SX1261 & RP2040 SPI speed and timing limits #938

Mictronics · 2024-01-20T20:08:38Z

Mictronics
Jan 20, 2024

I'm working with code from the Meshtastics project on the RP2040 platform in combination with a Waveshare LoRa SX1261 module.
To improve/decrease power consumption I reduced the RP2040 system clock. While the RP2040 accepts frequencies down to 18 MHz everthing below 23 MHz fails to detect the SX1261 using this radio lib.

With some tweaking of SPI speed (500 kHz indstead of 4 MHz) and an increasing RADIOLIB_MODULE_SPI_TIMEOUT to avoid GPIO timeout errors I was able to archive at least a chip detection and some initialization.
However, the init then asserts in setCodingRate

  // configure publicly accessible settings
  state = setCodingRate(cr);
  RADIOLIB_ASSERT(state);

resulting in

RadioLib Debug Info
Version:  6.4.0.0
Platform: Raspberry Pi Pico (unofficial)
Compiled: Jan 19 2024 19:50:26

Found SX126x: RADIOLIB_SX126X_REG_VERSION_STRING:
0000320 53 58 31 32 36 31 20 56 32 44 20 32 44 30 32 00 | SX1261 V2D 2D02.

M    SX126x
Calibration failed, device errors: 0x20

In general high SPI frequencies with lower system clock will result in SPI read errors and for example garbage in the above version string.

So my question:
Are there any experiences with how low the SPI can be clocked and/or timing can be lowered to make the SX1261 work?

jgromes · 2024-01-20T20:37:49Z

jgromes
Jan 20, 2024
Maintainer

increasing RADIOLIB_MODULE_SPI_TIMEOUT to avoid GPIO timeout errors

I'm guessing that at some point you got a debug message like "GPIO pre-transfer timeout, is it connected?". That suggests you either have an issue in the BUSY pin connection (unlikely if it works at higher speeds), or your lower clock speed is interfering with time measurement in the RP2040 Arduino core. Otherwise you're basically suggesting that the SX126x is taking longer to de-assert its busy signal when host MCU has slower clock, which seems rather implausible.

However, the init then asserts in setCodingRate

Is that really the place where it's failing? That would be surprising, could you post the output with debug+verbose? I would expect calibration errors to appear very early in initialization. The device error is 0x20 - quick look in the SX126x datasheet/SX126x header shows that this is RADIOLIB_SX126X_XOSC_START_ERR, failure to start the high-speed oscillator (crystal or TCXO). This is typical if you have incorrect TCXO voltage (again, unlikely if it works on higher MCU frequencies), or if the calibration process itself failed somehow. As part of that process, RadioLib waits for 5 ms before attempting to poll the BUSY pin for calibration completion. So again, either an issue in BUSY pin connection (unlikely) or an issue with time measurement.

Are there any experiences with how low the SPI can be clocked and/or timing can be lowered to make the SX1261 work?

All of those are platform-dependent questions; at the end of the day, RadioLib just calls SPI.transfer - what happens within that is up to your Arduino core. How did you verify the SPI is actually working at these frequencies/clock configurations? And did you check the SX1261 datasheet to verify that your SPI configuration actually meets the transceiver timing requirements?

0 replies

Mictronics · 2024-01-21T15:06:13Z

Mictronics
Jan 21, 2024
Author

I'm guessing that at some point you got a debug message like "GPIO pre-transfer timeout, is it connected?".

That's correct. I'm thinking also about time measurement issues but I didn't investigate further. All code works fine at 48 MHz system clock and 4 MHz SPI speed.

Is that really the place where it's failing?

Yes. I added a debug output after RADIOLIB_ASSERT in SX126x::begin and the assert was triggered after setCodingRate.

How did you verify the SPI is actually working at these frequencies/clock configurations?

Lowering the system clock but not touching the SPI clock results for example in garbage when querying RADIOLIB_SX126X_REG_VERSION_STRING, string not found at all or after several tries.

And did you check the SX1261 datasheet to verify that your SPI configuration actually meets the transceiver timing requirements?

Nope. My testing was a quick try to see what is possible in terms of power reduction. Then run into the radio lib issues but was not investigating into deep. Not sure if I will track this down further. This is why I asked for experience to see if it makes sense or not.

Thanks anyway for your feedback.

1 reply

jgromes Jan 21, 2024
Maintainer

Lowering the system clock but not touching the SPI clock results for example in garbage when querying RADIOLIB_SX126X_REG_VERSION_STRING, string not found at all or after several tries.

That seems to support the theory that the clock for the SPI peripheral is not configured correctly on low system clock settings.

Nope. My testing was a quick try to see what is possible in terms of power reduction. Then run into the radio lib issues but was not investigating into deep. Not sure if I will track this down further. This is why I asked for experience to see if it makes sense or not.

Seems to me exclusively like platform issues. There's not much RadioLib can do if you configure your system clock in such a way that the SPI peripheral stops working ;)

Mictronics · 2024-01-21T16:30:18Z

Mictronics
Jan 21, 2024
Author

Seems to me exclusively like platform issues. There's not much RadioLib can do if you configure your system clock in such a way that the SPI peripheral stops working ;)

Don't get me wrong. I do not blame radio lib or expect something. My question was purely about experience, if someone already tried low speed setups maybe etc. Just information exchange. I will think about some more and get back into this.

0 replies

secretman28 · 2024-02-14T01:07:03Z

secretman28
Feb 14, 2024

following

0 replies

HeadBoffin · 2024-02-14T10:15:02Z

HeadBoffin
Feb 14, 2024
Collaborator

Reducing the clock below a stable speed for SPI may well be a zero sum game as the Pico doesn't have any useful low power modes, so whilst you may save a few nJ by lowering the clock, the RP2040 doesn't appear to sleep at less than 1mA and most of your power on Meshtastic is burnt on Rx time anyway. It might be worth trying a board without radio to measure the standing current at the different clock levels.

0 replies

Mictronics · 2024-02-23T19:58:20Z

Mictronics
Feb 23, 2024
Author

Actual status: The problems with low sys clock are not caused by the SPI speed but the delay(ms) functions.
In Meshtastic code there are two global delay(ms) functions declared. One in framework-arduino for RP2040 and one in FreeRTOS. The one in framework-arduino is a weak symbol, hence overwritten by the one in FreeRTOS.

I did some tests with delaying a GPIO toggle and monitoring with a o-scope. The delay(ms) in framework-arduino provides a stable and reproducible delay by given time. Also delayMicroseconds works fine.
However, the delay(ms) from FreeRTOS causes a variable delay for a given time. Close to what is expected as long as the sys clock is high enough.
On low sys clock, 18 MHz, the RP2040 minimum, the delay(ms) is no longer reliable. A requested delay(1) results in real ~6.7ms while a delay(10) is up to 76ms.

With such unstable an unreliable delay the RadioLib is not working stable, some functions not at all. Not blaming the RadioLib here, just facts. When solved the Meshtastic code may run with 10-15mA on the Pico at 18MHz.

2 replies

jgromes Feb 23, 2024
Maintainer

That's an interesting observation - thanks! I'm not aware of any functionality in RadioLib that would depend on the millisecond counter being accurate. So this would probably require further digging to figure out where exactly does an unexpected delay length cause RadioLib to fail.

StevenCellist Feb 24, 2024
Collaborator

Side note that LoRaWAN does ;)

Mictronics · 2024-02-24T09:41:05Z

Mictronics
Feb 24, 2024
Author

The RadioLib may not fail directly but a returned status is maybe not as expected. The status byte has a command timeout flag that notes:
2. A transaction from host took too long to complete and triggered an internal watchdog. The watchdog mechanism can be disabled by host; it is meant to ensure all outcomes are flagged to the host MCU.

One function that reproducible has problems with inaccurate delay is findChip. With inaccurate delay it takes 3-5 iterations of the loop to detect the chip id string. The failed iterations are returning lots of 0xa2 or 0x00.

3 replies

jgromes Feb 24, 2024
Maintainer

Hmm ... I don't know where exactly the SX126x watchdog starts counting. If it's at the falling edge of NSS, then, in a multi-threaded environment, it could be possible that the thread RadioLib is running in gets blocked by a higher-priority thread, keeping the SPI transaction hanging, and the SX126x watchdog being triggered. So this could be a case of improperly handled thread priorities.

Mictronics Feb 26, 2024
Author

This might be the case. One more thing I found in Meshtastic code is that somewhere the NSS is set low before code enters SPItransfer or SPItransferStream.
I set an GPIO in parallel to NSS in both functions and in some cases the NSS is pulled low ~660us (@18MHz sys clock) before it should be low in transfer functions. Need to find where that happens.
So if your guess is applicable then everything might be fine on high sys_clock since the code timing might stay below such timeout.
Anyway, the watchdog is not mentioned in datasheet anywhere else except in that note on page 97. It's all another wild guess.

[Edit]
It's the standby wakeup that is pulling NSS low. However, I don't know where the delay is coming from. Busy pin is already low.

jgromes Feb 26, 2024
Maintainer

Anyway, the watchdog is not mentioned in datasheet anywhere else except in that note on page 97

Ah yes, Semtech docs strike again. It also mentions it can be disabled by the host MCU without any explanation as to how ;)

Mictronics · 2024-03-05T18:30:04Z

Mictronics
Mar 5, 2024
Author

So after endless fiddling with Meshtastic code and no success I stopped and took a different approach. Created a completely new platformio project for the Pico module, included just the radioLib. Took some code from the radioLib example "RadioLib/examples/SX126x/SX126x_Settings/SX126x_Settings.ino".

I see the same problems with SX1262 initialization at low RP2040 sys clock. Chip detection and init fails <18 MHz. Chip found, but other init failures 18 MHz > sys_clock < 24 MHz. Successful init > 24 MHz.

Still have no idea what the problem might be. This watchdog maybe?
I will keep fiddling with the code below to reduce complexity and exclude all the other Meshtastic code stuff.

That's the code I am running on a Pico with Waveshare LoRa module attached:

#include <Arduino.h>
#include <pico/stdlib.h>
#include <RadioLib.h>

#define LORA_SCK 10
#define LORA_MISO 12
#define LORA_MOSI 11
#define LORA_CS 3

#define LORA_RESET 15
#define LORA_DIO1 20
#define LORA_DIO2 2

#define SX126X_CS LORA_CS
#define SX126X_DIO1 LORA_DIO1
#define SX126X_BUSY LORA_DIO2
#define SX126X_RESET LORA_RESET

void setup()
{
  set_sys_clock_khz(24000, false);

  SPI1.setSCK(LORA_SCK);
  SPI1.setTX(LORA_MOSI);
  SPI1.setRX(LORA_MISO);
  pinMode(LORA_CS, OUTPUT);
  digitalWrite(LORA_CS, HIGH);
  SPI1.begin(false);

  SPISettings spiSettings(4000000, MSBFIRST, SPI_MODE0);
  SX1262 radio1 = new Module(SX126X_CS, SX126X_DIO1, SX126X_RESET, SX126X_BUSY, SPI1, spiSettings);

  Serial1.begin(115200);

  // initialize SX1268 with default settings
  Serial1.print(F("[SX1262] Initializing ... "));
  int state = radio1.begin();
  if (state == RADIOLIB_ERR_NONE)
  {
    Serial1.println(F("success!"));
  }
  else
  {
    Serial1.print(F("failed, code "));
    Serial1.println(state);
    while (true)
      ;
  }

  // set carrier frequency to 869.525 MHz
  if (radio1.setFrequency(869.525) == RADIOLIB_ERR_INVALID_FREQUENCY)
  {
    Serial1.println(F("Selected frequency is invalid for this module!"));
    while (true)
      ;
  }

  // set bandwidth to 250 kHz
  if (radio1.setBandwidth(250.0) == RADIOLIB_ERR_INVALID_BANDWIDTH)
  {
    Serial1.println(F("Selected bandwidth is invalid for this module!"));
    while (true)
      ;
  }

  // set spreading factor to 10
  if (radio1.setSpreadingFactor(10) == RADIOLIB_ERR_INVALID_SPREADING_FACTOR)
  {
    Serial1.println(F("Selected spreading factor is invalid for this module!"));
    while (true)
      ;
  }

  // set coding rate to 6
  if (radio1.setCodingRate(6) == RADIOLIB_ERR_INVALID_CODING_RATE)
  {
    Serial1.println(F("Selected coding rate is invalid for this module!"));
    while (true)
      ;
  }

  // set LoRa sync word to 0x2B
  if (radio1.setSyncWord(0x2B) != RADIOLIB_ERR_NONE)
  {
    Serial1.println(F("Unable to set sync word!"));
    while (true)
      ;
  }

  // set output power to 10 dBm (accepted range is -17 - 22 dBm)
  if (radio1.setOutputPower(10) == RADIOLIB_ERR_INVALID_OUTPUT_POWER)
  {
    Serial1.println(F("Selected output power is invalid for this module!"));
    while (true)
      ;
  }

  // set over current protection limit to 80 mA (accepted range is 45 - 240 mA)
  // NOTE: set value to 0 to disable overcurrent protection
  if (radio1.setCurrentLimit(80) == RADIOLIB_ERR_INVALID_CURRENT_LIMIT)
  {
    Serial1.println(F("Selected current limit is invalid for this module!"));
    while (true)
      ;
  }

  // set LoRa preamble length to 15 symbols (accepted range is 0 - 65535)
  if (radio1.setPreambleLength(15) == RADIOLIB_ERR_INVALID_PREAMBLE_LENGTH)
  {
    Serial1.println(F("Selected preamble length is invalid for this module!"));
    while (true)
      ;
  }

  // disable CRC
  if (radio1.setCRC(false) == RADIOLIB_ERR_INVALID_CRC_CONFIGURATION)
  {
    Serial1.println(F("Selected CRC is invalid for this module!"));
    while (true)
      ;
  }

  radio1.sleep(true);
  Serial1.println(F("done!"));
}

void loop()
{
  // put your main code here, to run repeatedly:
}

8 replies

Mictronics Mar 6, 2024
Author

18MHz GET_STATUS

18MHz NSS to first clock

18MHz read ID string complete

18MHz reset - 10ms resolution to record reset sequence

18MHz SPI clock

24MHz GET_STATUS

24MHz NSS to first clock

24MHz read ID string complete

24MHz reset - 5ms resolution, only one reset pulse

24MHz SPI clock
Signals:
D0 = NSS
D1 = CLK
D2 = MOSI
D3 = MISO
D4 = BUSY
D5 = TEST GPIO for triggering purpose
D6 = not used, label wrong
D7 = RESET

Taken with 18MHz and 24MHz sys_clock.

If you wand to see something specific let me know.

Mictronics Mar 6, 2024
Author

One thing I noticed: at 24MHz I see much more BUSY activity then with 18MHz, and at 18MHz I get sporadic -706 and -707 errors.

jgromes Mar 7, 2024
Maintainer

Thanks for the screenshots. At first glance, something weird is definitely happening when reading the ID string at 18 MHz. MOSI seems to be sending out data in the middle of the ID string read. I would expect it to only send the command and register address at the beginning of the read - just like is the case at 24 MHz. There you can clearly see the first three bytes sent from RP2040, and then just NOPs (0x00). I have no idea why it's so broken at 18 MHz, but if this happens for other commands as well, that will for sure break the communication.

Alright, fine, you got me - ordered a couple cheap RP2040s, let's get to the bottom of this.

Mictronics Mar 7, 2024
Author

Reading ID string in detail at 18MHz:

Byte 1

Byte 2

Byte 3

Byte 4

Byte 5

Bytes 6-8, 10, 12, 15-19

Byte 9

Byte 11

Byte 13

Byte 14

Byte 20

Mictronics Mar 7, 2024
Author

Boot with SPI init and Id string read at 18MHz.

SPI::begin(0), rx=12, cs=13, sck=10, tx=11
SPI::beginTransaction(clk=0, bo=LSB)
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
[SX1262] Initializing ... 
RadioLib Debug Info
Version:  6.4.2.0
Platform: Raspberry Pi Pico (unofficial)
Compiled: Mar  5 2024 20:13:16

SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: deinitting currently active SPI
SPI: initting SPI
SPI: actual baudrate=4000000
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP CMD_SET_NOP
SPI: read back aa
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP CMD_SET_NOP
SPI: read back aa
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP CMD_SET_NOP
SPI: read back aa
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP CMD_SET_NOP
SPI: read back aa
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP CMD_SET_NOP
SPI: read back aa
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP CMD_SET_NOP
SPI: read back a2
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(c0), cpol=0, cpha=0 CMD_GET_STATUS
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP CMD_SET_NOP
SPI: read back a2
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(1d), cpol=0, cpha=0 CMD_READ_REGISTER
SPI: read back a2
SPI::transfer(03), cpol=0, cpha=0 REG_VERSION_STRING
SPI: read back a2
SPI::transfer(20), cpol=0, cpha=0 REG_VERSION_STRING
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SX126x not found! (1 of 10 tries) RADIOLIB_SX126X_REG_VERSION_STRING:
0000320 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 | ................
Expected string: SX1261
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 2a
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back aa
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back aa
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(c0), cpol=0, cpha=0 CMD_GET_STATUS
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(1d), cpol=0, cpha=0 CMD_READ_REGISTER
SPI: read back a2
SPI::transfer(03), cpol=0, cpha=0 REG_VERSION_STRING
SPI: read back a2
SPI::transfer(20), cpol=0, cpha=0 REG_VERSION_STRING
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 5b
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back ca
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 0c
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 1b
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back c0
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 00
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back b8
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back ae
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 8f
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 01
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 42
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back ac
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 75
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 1a
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back e1
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back d5
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SX126x not found! (2 of 10 tries) RADIOLIB_SX126X_REG_VERSION_STRING:
0000320 5b ca 0c 1b c0 00 b8 ae 8f 01 42 ac 75 1a e1 d5 | [.........B.u...
Expected string: SX1261
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 2a
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back aa
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: transfer(00), cpol=0, cpha=0
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SX126x not found! (5 of 10 tries) RADIOLIB_SX126X_REG_VERSION_STRING:
0000320 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 | ................
Expected string: SX1261
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 2a
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back aa
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back aa
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(c0), cpol=0, cpha=0 CMD_GET_STATUS
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(1d), cpol=0, cpha=0 CMD_READ_REGISTER
SPI: read back a2
SPI::transfer(03), cpol=0, cpha=0 REG_VERSION_STRING
SPI: read back a2
SPI::transfer(20), cpol=0, cpha=0 REG_VERSION_STRING
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 00
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 1d
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 03
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 00
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 9a
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 04
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 20
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 00
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 00
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 00
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 00
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 00
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 00
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 00
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 00
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SX126x not found! (6 of 10 tries) RADIOLIB_SX126X_REG_VERSION_STRING:
0000320 00 a2 1d 03 00 9a 04 20 00 00 00 00 00 00 00 00 | ....... ........
Expected string: SX1261
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 2a
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back aa
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(c0), cpol=0, cpha=0 CMD_GET_STATUS
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(1d), cpol=0, cpha=0 CMD_READ_REGISTER
SPI: read back a2
SPI::transfer(03), cpol=0, cpha=0 REG_VERSION_STRING
SPI: read back a2
SPI::transfer(20), cpol=0, cpha=0 REG_VERSION_STRING
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SX126x not found! (7 of 10 tries) RADIOLIB_SX126X_REG_VERSION_STRING:
0000320 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 | ................
Expected string: SX1261
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back 2a
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back aa
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back aa
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back aa
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SPI::beginTransaction(clk=4000000, bo=MSB)
SPI: Reusing existing initted SPI
SPI: IRQ masks before = 00000000 00000000 00000000 00000000
SPI: IRQ masks after = 00000000 00000000 00000000 00000000
SPI::transfer(80), cpol=0, cpha=0 CMD_SET_STANDBY
SPI: read back a2
SPI::tra
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::transfer(00), cpol=0, cpha=0 CMD_SET_NOP
SPI: read back a2
SPI::endTransaction()
SPI: IRQ masks = 00000000 00000000 00000000 00000000
SX126x not found! (10 of 10 tries) RADIOLIB_SX126X_REG_VERSION_STRING:
0000320 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 a2 | ................
Expected string: SX1261
No SX126x found!
failed, code -2

Mictronics · 2024-03-07T18:58:45Z

Mictronics
Mar 7, 2024
Author

Some more weird things here. Sending a triple 0x55 command at 18 and 24 MHz.

uint8_t cmd[] = {0x55,0x55,0x55};
SPItransferStream(cmd, 3, false, NULL, inBytes, 16, true, RADIOLIB_MODULE_SPI_TIMEOUT);

@18MHz the command bytes are not in sequence ?! But still 20 bytes are clocked out. Really weird.

@24MHz as expected.

13 replies

Mictronics Mar 9, 2024
Author

I really think you should report this to the RP2040 Arduino core, seems like a major issue.

Is that the repo maintained by Earle Philhower, arduino-pico?

jgromes Mar 9, 2024
Maintainer

Well .. you tell me, which core are you using? There's the one you mentioned, but also an official one maintained by Arduino, which is supposedly a lot worse.

Mictronics Mar 9, 2024
Author

It's the framework-arduinopico which is the default package in platformio: https://github.com/earlephilhower/arduino-pico/
So the issue goes there then.

Mictronics Mar 9, 2024
Author

Issue raised earlephilhower/arduino-pico#2048

Mictronics Mar 9, 2024
Author

Another test about checking and setting sys_clk using example code from the SDK: hello_48MHz.c

In this output the code start with default F_CPU at 133MHz and then sets sys_clk to 18MHz.

Start
pll_sys  = 133000kHz
pll_usb  = 48000kHz
rosc     = 5626kHz
clk_sys  = 133001kHz
clk_peri = 48000kHz
clk_usb  = 48000kHz
clk_adc  = 48000kHz
clk_rtc  = 47kHz
Set sys_clk
pll_sys  = 18000kHz
pll_usb  = 48000kHz
rosc     = 5638kHz
clk_sys  = 18000kHz
clk_peri = 48000kHz
clk_usb  = 48000kHz
clk_adc  = 48000kHz
clk_rtc  = 47kHz

In the following output F_CPU was redefined and the code already starts with sys_clk at 18MHz.

Start
pll_sys  = 18000kHz
pll_usb  = 48000kHz
rosc     = 5638kHz
clk_sys  = 18000kHz
clk_peri = 48000kHz
clk_usb  = 48000kHz
clk_adc  = 48000kHz
clk_rtc  = 47kHz
Set sys_clk
pll_sys  = 18000kHz
pll_usb  = 48000kHz
rosc     = 5641kHz
clk_sys  = 18000kHz
clk_peri = 48000kHz
clk_usb  = 48000kHz
clk_adc  = 48000kHz
clk_rtc  = 47kHz

With such clock settings the SPI should work flawlessly at 18MHz and any desired SPI clock. Peripheral clock at 48MHz is more than sufficient I guess for an 4MHz SPI clock.
Maybe the SPI is overflowing the core at 18MHz but why it works at 24MHz then, no idea.

[Edit]
SPI is running at 48MHz peripheral clock when sys_clock is modified.

// By default, clk_peri (which drives the serial parts of SPI and UART) is
// attached directly to clk_sys, so varies if the system clock is scaled up
// and down. clk_peri has a multiplexer (though no divider) which allows it to
// be attached to other sources.
//
// If set_sys_clock_khz is called (here setting the system clock to 133 MHz),
// this automatically attaches clk_peri to the USB PLL, which by default we run
// at 48 MHz. As long as you call this *before* configuring your UART etc, the
// UART baud rate will then not be affected by subsequent changes to clk_sys.
//
// However, dropping clk_peri to 48 MHz limits the maximum serial frequencies
// that can be attained by UART and particularly SPI. This example shows how
// clk_peri can be attached directly to the system PLL, and the clk_sys
// divider can then be varied to scale the system (CPUs, DMA, bus fabric etc)
// frequency up and down whilst keeping clk_peri at a constant 133 MHz.

Source: https://github.com/raspberrypi/pico-examples/blob/master/clocks/detached_clk_peri/detached_clk_peri.c

Mictronics · 2024-03-09T16:42:31Z

Mictronics
Mar 9, 2024
Author

Woohoo!!! Awesome it works!!!

pll_sys  = 18000kHz
pll_usb  = 48000kHz
rosc     = 5633kHz
clk_sys  = 18000kHz
clk_peri = 18000kHz
clk_usb  = 48000kHz
clk_adc  = 48000kHz
clk_rtc  = 47kHz
[SX1262] Initializing ... 
RadioLib Debug Info
Version:  6.4.2.0
Platform: Raspberry Pi Pico (unofficial)
Compiled: Mar  9 2024 17:34:27

Found SX126x: RADIOLIB_SX126X_REG_VERSION_STRING:
0000320 53 58 31 32 36 31 20 56 32 44 20 32 44 30 32 00 | SX1261 V2D 2D02.

M	SX126x
success!
done!

The solution is so simple!
After set_sys_clock_khz the peripheral clock must be switched back to clk_sys, so both running with the same frequency.

That's the code for above output:

#include <Arduino.h>
#include <pico/stdlib.h>
#include <RadioLib.h>
#include <hardware/spi.h>
#include <stdio.h>
#include <hardware/pll.h>
#include <hardware/clocks.h>
#include <hardware/structs/pll.h>
#include <hardware/structs/clocks.h>

#define LORA_SCK 10
#define LORA_MISO 12
#define LORA_MOSI 11
#define LORA_CS 3

#define LORA_RESET 15
#define LORA_DIO1 20
#define LORA_DIO2 2

#define SX126X_CS LORA_CS
#define SX126X_DIO1 LORA_DIO1
#define SX126X_BUSY LORA_DIO2
#define SX126X_RESET LORA_RESET

static void measure_freqs(void)
{
  uint f_pll_sys = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_PLL_SYS_CLKSRC_PRIMARY);
  uint f_pll_usb = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_PLL_USB_CLKSRC_PRIMARY);
  uint f_rosc = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_ROSC_CLKSRC);
  uint f_clk_sys = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_CLK_SYS);
  uint f_clk_peri = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_CLK_PERI);
  uint f_clk_usb = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_CLK_USB);
  uint f_clk_adc = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_CLK_ADC);
  uint f_clk_rtc = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_CLK_RTC);

  Serial1.printf("pll_sys  = %dkHz\n", f_pll_sys);
  Serial1.printf("pll_usb  = %dkHz\n", f_pll_usb);
  Serial1.printf("rosc     = %dkHz\n", f_rosc);
  Serial1.printf("clk_sys  = %dkHz\n", f_clk_sys);
  Serial1.printf("clk_peri = %dkHz\n", f_clk_peri);
  Serial1.printf("clk_usb  = %dkHz\n", f_clk_usb);
  Serial1.printf("clk_adc  = %dkHz\n", f_clk_adc);
  Serial1.printf("clk_rtc  = %dkHz\n", f_clk_rtc);

  // Can't measure clk_ref / xosc as it is the ref
}

void setup()
{
  set_sys_clock_khz(18000, false);
  clock_configure(
      clk_peri,
      0,                                                // No glitchless mux
      CLOCKS_CLK_PERI_CTRL_AUXSRC_VALUE_CLKSRC_PLL_SYS, // System PLL on AUX mux
      18000 * 1000,                                     // Input frequency
      18000 * 1000                                      // Output (must be same as no divider)
  );

  Serial1.begin(115200);
  measure_freqs();

  SPI1.setSCK(LORA_SCK);
  SPI1.setTX(LORA_MOSI);
  SPI1.setRX(LORA_MISO);
  pinMode(LORA_CS, OUTPUT);
  digitalWrite(LORA_CS, HIGH);
  SPI1.begin(false);

  SPISettings spiSettings(4000000, MSBFIRST, SPI_MODE0);
  SX1262 radio1 = new Module(SX126X_CS, SX126X_DIO1, SX126X_RESET, SX126X_BUSY, SPI1, spiSettings);

  // initialize SX1268 with default settings
  Serial1.print(F("[SX1262] Initializing ... "));
  int state = radio1.begin();
  if (state == RADIOLIB_ERR_NONE)
  {
    Serial1.println(F("success!"));
  }
  else
  {
    Serial1.print(F("failed, code "));
    Serial1.println(state);
    while (true)
      ;
  }

  // set carrier frequency to 869.525 MHz
  if (radio1.setFrequency(869.525) == RADIOLIB_ERR_INVALID_FREQUENCY)
  {
    Serial1.println(F("Selected frequency is invalid for this module!"));
    while (true)
      ;
  }

  // set bandwidth to 250 kHz
  if (radio1.setBandwidth(250.0) == RADIOLIB_ERR_INVALID_BANDWIDTH)
  {
    Serial1.println(F("Selected bandwidth is invalid for this module!"));
    while (true)
      ;
  }

  // set spreading factor to 10
  if (radio1.setSpreadingFactor(10) == RADIOLIB_ERR_INVALID_SPREADING_FACTOR)
  {
    Serial1.println(F("Selected spreading factor is invalid for this module!"));
    while (true)
      ;
  }

  // set coding rate to 6
  if (radio1.setCodingRate(6) == RADIOLIB_ERR_INVALID_CODING_RATE)
  {
    Serial1.println(F("Selected coding rate is invalid for this module!"));
    while (true)
      ;
  }

  // set LoRa sync word to 0x2B
  if (radio1.setSyncWord(0x2B) != RADIOLIB_ERR_NONE)
  {
    Serial1.println(F("Unable to set sync word!"));
    while (true)
      ;
  }

  // set output power to 10 dBm (accepted range is -17 - 22 dBm)
  if (radio1.setOutputPower(10) == RADIOLIB_ERR_INVALID_OUTPUT_POWER)
  {
    Serial1.println(F("Selected output power is invalid for this module!"));
    while (true)
      ;
  }

  // set over current protection limit to 80 mA (accepted range is 45 - 240 mA)
  // NOTE: set value to 0 to disable overcurrent protection
  if (radio1.setCurrentLimit(80) == RADIOLIB_ERR_INVALID_CURRENT_LIMIT)
  {
    Serial1.println(F("Selected current limit is invalid for this module!"));
    while (true)
      ;
  }

  // set LoRa preamble length to 15 symbols (accepted range is 0 - 65535)
  if (radio1.setPreambleLength(15) == RADIOLIB_ERR_INVALID_PREAMBLE_LENGTH)
  {
    Serial1.println(F("Selected preamble length is invalid for this module!"));
    while (true)
      ;
  }

  // disable CRC
  if (radio1.setCRC(false) == RADIOLIB_ERR_INVALID_CRC_CONFIGURATION)
  {
    Serial1.println(F("Selected CRC is invalid for this module!"));
    while (true)
      ;
  }

  radio1.sleep(true);
}

void loop()
{
  // put your main code here, to run repeatedly:
}

0 replies

Mictronics · 2024-03-09T17:14:29Z

Mictronics
Mar 9, 2024
Author

Meshtastic code is working!

//\ E S H T /\ S T / C

INFO  | ??:??:?? 0 Clock speed:
INFO  | ??:??:?? 0 pll_sys  = 18000kHz
INFO  | ??:??:?? 0 pll_usb  = 48000kHz
INFO  | ??:??:?? 0 rosc     = 5636kHz
INFO  | ??:??:?? 0 clk_sys  = 18000kHz
INFO  | ??:??:?? 0 clk_peri = 18000kHz
INFO  | ??:??:?? 0 clk_usb  = 48000kHz
INFO  | ??:??:?? 0 clk_adc  = 48000kHz
INFO  | ??:??:?? 0 clk_rtc  = 47kHz
DEBUG | ??:??:?? 0 Filesystem files:
DEBUG | ??:??:?? 0  channels.proto (186 Bytes)
lfs_file_close: fd=0x200138b4
DEBUG | ??:??:?? 0  config.proto (93 Bytes)
lfs_file_close: fd=0x200138b4
DEBUG | ??:??:?? 0  db.proto (606 Bytes)
lfs_file_close: fd=0x200138b4
DEBUG | ??:??:?? 0  module.proto (100 Bytes)
lfs_file_close: fd=0x200138b4
DEBUG | ??:??:?? 0 Using analog input 26 for battery level
INFO  | ??:??:?? 0 Scanning for i2c devices...
DEBUG | ??:??:?? 0 Scanning for i2c devices on port 2
DEBUG | ??:??:?? 0 I2C device found at address 0x3c
INFO  | ??:??:?? 0 sh1106 display found
INFO  | ??:??:?? 0 sh1106 display found
DEBUG | ??:??:?? 0 0x8 subtype probed in 2 tries 
DEBUG | ??:??:?? 0 I2C device found at address 0x76
DEBUG | ??:??:?? 0 Wire.available() = 1
INFO  | ??:??:?? 0 BME-280 sensor found at address 0x76
DEBUG | ??:??:?? 0 Scanning for i2c devices on port 1
INFO  | ??:??:?? 0 2 I2C devices found
DEBUG | ??:??:?? 0 acc_info = 0
DEBUG | ??:??:?? 0 found i2c sensor meshtastic_TelemetrySensorType_BME280
INFO  | ??:??:?? 0 Meshtastic hwvendor=47, swver=2.2.25.0d3b50d6
INFO  | ??:??:?? 1 Initializing NodeDB
INFO  | ??:??:?? 1 Loading /prefs/db.proto
lfs_file_close: fd=0x200136c4
INFO  | ??:??:?? 1 Loaded saved devicestate version 22
INFO  | ??:??:?? 1 Loading /prefs/config.proto
lfs_file_close: fd=0x200136c4
INFO  | ??:??:?? 1 Loaded saved config version 22
INFO  | ??:??:?? 1 Loading /prefs/module.proto
lfs_file_close: fd=0x200136c4
INFO  | ??:??:?? 1 Loaded saved moduleConfig version 22
INFO  | ??:??:?? 1 Loading /prefs/channels.proto
lfs_file_close: fd=0x200136c4
INFO  | ??:??:?? 1 Loaded saved channelFile version 22
LittleFSDirImpl::openFile: rc=-2 fd=0x200136c4 path=`/oem/oem.proto` openMode=0 accessMode=1 err=-2
INFO  | ??:??:?? 1 No /oem/oem.proto preferences found
DEBUG | ??:??:?? 1 cleanupMeshDB purged 0 entries
WARN  | ??:??:?? 1 Using nodenum 0x17322735 
DEBUG | ??:??:?? 1 Expanding short PSK #1
INFO  | ??:??:?? 1 Wanted region 3, using EU_868
DEBUG | ??:??:?? 1 region=3, NODENUM=0x17322735, dbsize=6
DEBUG | ??:??:?? 1 Using GPIO18 for button
DEBUG | ??:??:?? 1 Read RTC time as 2448
DEBUG | ??:??:?? 1 Running without GPS.
DEBUG | ??:??:?? 1 NeighborInfoModule is disabled
INFO  | ??:??:?? 1 External Notification Module Disabled
INFO  | ??:??:?? 1 Turning on screen
DEBUG | ??:??:?? 1 Module wants a UI Frame
WARN  | ??:??:?? 1 SX126xInterface(cs=3, irq=20, rst=15, busy=2)
DEBUG | ??:??:?? 1 SX126X_DIO3_TCXO_VOLTAGE defined, using DIO3 as TCXO reference voltage at 1.800000 V
INFO  | ??:??:?? 1 Starting meshradio init...
DEBUG | ??:??:?? 1 (bw=250, sf=11, cr=4/5) packet symLen=8 ms, payloadSize=0, time 231 ms
DEBUG | ??:??:?? 1 (bw=250, sf=11, cr=4/5) packet symLen=8 ms, payloadSize=253, time 2115 ms
INFO  | ??:??:?? 1 Radio freq=869.525, config.lora.frequency_offset=0.000
INFO  | ??:??:?? 1 Set radio: region=EU_868, name=Private, config=0, ch=0, power=27
INFO  | ??:??:?? 1 Radio myRegion->freqStart -> myRegion->freqEnd: 869.400024 -> 869.650024 (0.250000 mhz)
INFO  | ??:??:?? 2 Radio myRegion->numChannels: 1 x 250.000kHz
INFO  | ??:??:?? 2 Radio channel_num: 1
INFO  | ??:??:?? 2 Radio frequency: 869.525024
INFO  | ??:??:?? 2 Slot time: 42 msec
INFO  | ??:??:?? 2 Set radio: final power level=22
RadioLib Debug Info
Version:  6.4.2.0
Platform: Raspberry Pi Pico (unofficial)
Compiled: Mar  9 2024 17:56:22

Found SX126x: RADIOLIB_SX126X_REG_VERSION_STRING:
0000320 53 58 31 32 36 31 20 56 32 44 20 32 44 30 32 00 | SX1261 V2D 2D02.

M	SX126x
INFO  | ??:??:?? 2 SX126x init result 0
INFO  | ??:??:?? 2 Frequency set to 869.525024
INFO  | ??:??:?? 2 Bandwidth set to 250.000000
INFO  | ??:??:?? 2 Power output set to 22
DEBUG | ??:??:?? 2 Current limit set to 140.000000
DEBUG | ??:??:?? 2 Current limit set result 0
DEBUG | ??:??:?? 2 Setting DIO2 as RF switch
DEBUG | ??:??:?? 2 SX126X_RXEN not defined, defaulting to RADIOLIB_NC
DEBUG | ??:??:?? 2 SX126X_TXEN not defined, defaulting to RADIOLIB_NC
DEBUG | ??:??:?? 2 Using MCU pin -1 as RXEN and pin -1 as TXEN to control RF switching
INFO  | ??:??:?? 2 Set RX gain to boosted mode; result: 0
Auto sleep period: 0
Auto wake period: 73728
INFO  | ??:??:?? 2 SX1262 Radio init succeeded, using SX1262 radio

2 replies

jgromes Mar 9, 2024
Maintainer

Awesome, good job!

Mictronics Mar 9, 2024
Author

Thanks for staying with me on that topic. 😉 👍

Provide feedback

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SX1261 & RP2040 SPI speed and timing limits #938

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