electronic_kit.md

Electronic kit

I bought this kit: https://www.amazon.co.jp/gp/product/B00MRQ5U1Y/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

##Parts

• MCP3008

• MCP9700-E/TO

• MI5

• SG90(Servo motor)

I have installed pi-blaster to enable PWM on my Raspberry Pi 3.

I modified the constant in "pi-blaster.c" to adjust PWM frequency to 50Hz:

- #define CYCLE_TIME_US   10000
+ #define CYCLE_TIME_US   20000
  #define SAMPLE_US               10
  #define NUM_SAMPLES             (CYCLE_TIME_US/SAMPLE_US)
  #define NUM_CBS                 (NUM_SAMPLES*2)

I connected my servo motor (SG90) to GPIO21, 5V and GND, then I tested that the motor rotates its arm from -90 degree to +90 degree:

$ sudo ./pi-blaster -g 21
$ sudo echo "21=0.025" > /dev/pi-blaster
$ sudo echo "21=0.125" > /dev/pi-blaster

Temperature calculation

####MCP9700 DC electrical characteristics

####MCP3008 digital output code calculation

####Temperature calculation

##Luminousity calculation

##Communicating with MCP3008 via SPI

Control bit: 1000

Send [0x01, 0x80, 0x00] from your Raspberry Pi to MCP3008 via SPI. MCP3008 returns 10bit data (value range: 0 - 1023).

##Code I made this code to obtain the output from MCP3008(CH0 and CH1) and calcuate the temperature and luminousity.

##Wirling

Pin	Name	Direction	Part
9	GND
17	3.3V
19	SPI0 MOSI		AD converter
21	SPI0 MISO		AD converter
23	SPI0 SCLK		AD converter
24	SPI0 CS0		AD converter
29	GPIO5	out	LED green
31	GPIO6	out	LED red
33	GPIO13	out	piezo buzzer
35	GPIO19	in	tactile switch

Note: one analog thermistor and one CdS are connected to the AD converter.