AP_ICEngine : Fuel pump implementation and cleanup

libraries/AP_ICEngine/AP_ICEngine.cpp

@@ -643,6 +643,10 @@ void AP_ICEngine::set_ignition(bool on)
     }
 #endif // AP_RELAY_ENABLED
 
+#if AP_ICENGINE_TCA9554_STARTER_ENABLED
+    tca9554_starter.set_ignition(on);
+#endif
+
 }
 
 /*

libraries/AP_ICEngine/AP_ICEngine_TCA9554.cpp

@@ -11,21 +11,31 @@ extern const AP_HAL::HAL& hal;
 
 /*
  * TCA9554 output register mapping for PMB Rev E
- * P0 = PMU_EN - PMU output ON/OFF  (CN6 pin 2)
- * P1 = ECU_EN - Unused (previously Engine Kill Switch)
+ * (Net labels in the schematic are out of date, but shown for reference)
+ * P0 = PMU_EN - Unused
+ * P1 = ECU_EN - Fuel Pump MOSFET (CN5 pin 3)
  * P2 = I2C_P2 - Unused
  * P3 = LED (active low)
  * P4 = PMU_START - Crank Direction (CN6 pin 5)
- * P5 = PMU_ARM  - Crank Signal (CN6 pin 6)
+ * P5 = PMU_ARM  - Crank Signal (CN6 pin 6) (active low)
  * P6 = PMU_STAT_IN - Unused
  * P7 = PMU_STAT - Unused
  */
+enum PIN_MASK {
+    FUEL_PUMP       = 1 << 1,
+    LED_OFF         = 1 << 3,           
+    REVERSE         = 1 << 4,
+    STOP_CRANKING   = 1 << 5,
+};
+
 #define TCA9554_I2C_BUS      1
 #define TCA9554_I2C_ADDR     0x20
 #define TCA9554_OUTPUT       0x01  // Output Port register address. Outgoing logic levels
-#define TCA9554_OUT_DEFAULT  0x30  // 0011 0000
+#define TCA9554_OUT_DEFAULT  (LED_OFF | STOP_CRANKING)
 #define TCA9554_CONF         0x03  // Configuration Port register address [0 = Output]
-#define TCA9554_PINS         0xC2  // Set all used ports to outputs = 1100 0010
+#define TCA9554_PINS         (~(FUEL_PUMP | LED_OFF | REVERSE | STOP_CRANKING))  // Set all used ports to outputs
+
+#define FUEL_PUMP_PRIMING_TIME_MS 30000
 
 /*
   initialise TCA9554
@@ -60,7 +70,7 @@ bool AP_ICEngine_TCA9554::TCA9554_init()
 /*
   set the state of the i2c controller
  */
-void AP_ICEngine_TCA9554::TCA9554_set(TCA9554_state_t value)
+void AP_ICEngine_TCA9554::TCA9554_set(uint8_t value)
 {
     const uint32_t now_ms = AP_HAL::millis();
     if (now_ms - last_reg_check_ms > 100) {
@@ -76,7 +86,7 @@ void AP_ICEngine_TCA9554::TCA9554_set(TCA9554_state_t value)
     if (value != last_state) {
         WITH_SEMAPHORE(dev_TCA9554->get_semaphore());
         // set outputs and status leds
-        if (dev_TCA9554->write_register(TCA9554_OUTPUT, (~(value<<2) & 0x0C) | value)) {
+        if (dev_TCA9554->write_register(TCA9554_OUTPUT, value)) {
             last_state = value;
         }
     }
@@ -91,11 +101,14 @@ void AP_ICEngine_TCA9554::set_starter(bool on, AP_Int8 crank_direction)
             return;
         }
     }
-    if (!crank_direction) {
-        TCA9554_set(on? STARTER_FORWARD : STARTER_OFF);
-    } else {
-        TCA9554_set(on? STARTER_REVERSE : STARTER_OFF);
+    uint8_t value = on ? 0 : STOP_CRANKING | LED_OFF;
+    if (crank_direction) {
+        value |= REVERSE;
+    }
+    if (ignition_on || AP_HAL::millis64() < FUEL_PUMP_PRIMING_TIME_MS) {
+        value |= FUEL_PUMP;
     }
+    TCA9554_set(value);
 }
 
 #endif // AP_ICENGINE_TCA9554_STARTER_ENABLED

libraries/AP_ICEngine/AP_ICEngine_TCA9554.h

@@ -9,22 +9,19 @@
 
 class AP_ICEngine_TCA9554 {
 public:
+    void set_ignition(bool on) { ignition_on = on; }
     void set_starter(bool on, AP_Int8 crank_direction);
 
 private:
     AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev_TCA9554;
 
-    enum TCA9554_state_t {
-        STARTER_OFF = 0x30, // output register - 0011 0000
-        STARTER_FORWARD = 0x11, // output register - 0001 0001 - Forward direction
-        STARTER_REVERSE = 0x01, // output register - 0000 0001 - Reverse direction
-    };
-    TCA9554_state_t last_state;
+    uint8_t last_state;
 
     bool initialised;
+    bool ignition_on;
 
     bool TCA9554_init();
-    void TCA9554_set(TCA9554_state_t value);
+    void TCA9554_set(uint8_t value);
     uint32_t last_reg_check_ms;
 };