#211 Fixed vl53 deck driver hijacking i2c buss.

The vl53 deck driver used interrupt polling and a periodic timer to read
out sensor data. The periodic timer was running faster then the vl53
sensor could provide values leaving the driver in a constant polling
state. This had the consequence that the mem subsystem, having a lower
priority, never got to read the eeprom on the same i2c buss. A
relaxation delay was added to fix this. Also the sensor reading was
changed from every 100ms to as fast as possible.

src/config/config.h

@@ -82,6 +82,7 @@
 #define CRTP_TX_TASK_PRI        2
 #define CRTP_RX_TASK_PRI        2
 #define EXTRX_TASK_PRI          2
+#define VL53_TASK_PRI           2
 #define LOG_TASK_PRI            1
 #define MEM_TASK_PRI            1
 #define PARAM_TASK_PRI          1
@@ -125,6 +126,7 @@
 #define PROXIMITY_TASK_NAME     "PROXIMITY"
 #define EXTRX_TASK_NAME         "EXTRX"
 #define UART_RX_TASK_NAME       "UART"
+#define VL53_TASK_NAME          "VL53"
 
 //Task stack sizes
 #define SYSTEM_TASK_STACKSIZE         (2* configMINIMAL_STACK_SIZE)
@@ -145,6 +147,7 @@
 #define PROXIMITY_TASK_STACKSIZE      configMINIMAL_STACK_SIZE
 #define EXTRX_TASK_STACKSIZE          configMINIMAL_STACK_SIZE
 #define UART_RX_TASK_STACKSIZE        configMINIMAL_STACK_SIZE
+#define VL53_TASK_STACKSIZE           (2 * configMINIMAL_STACK_SIZE)
 
 //The radio channel. From 0 to 125
 #define RADIO_CHANNEL 80

src/deck/drivers/src/vl53l0x.c

@@ -147,7 +147,7 @@ void vl53l0xInit(DeckInfo* info)
   i2cdevInit(I2C1_DEV);
   I2Cx = I2C1_DEV;
   devAddr = VL53L0X_DEFAULT_ADDRESS;
-  xTaskCreate(vl53l0xTask, "vl53l0x", 2*configMINIMAL_STACK_SIZE, NULL, 3, NULL);
+  xTaskCreate(vl53l0xTask, VL53_TASK_NAME, VL53_TASK_STACKSIZE, NULL, VL53_TASK_PRI, NULL);
 
 #if defined(ESTIMATOR_TYPE_kalman) && defined(UPDATE_KALMAN_WITH_RANGING)
   // pre-compute constant in the measurement noise mdoel
@@ -177,7 +177,7 @@ void vl53l0xTask(void* arg)
 
   vl53l0xSetVcselPulsePeriod(VcselPeriodPreRange, 18);
   vl53l0xSetVcselPulsePeriod(VcselPeriodFinalRange, 14);
-  vl53l0xStartContinuous(100);
+  vl53l0xStartContinuous(0);
   while (1) {
     xLastWakeTime = xTaskGetTickCount();
     range_last = vl53l0xReadRangeContinuousMillimeters();
@@ -912,6 +912,11 @@ uint16_t vl53l0xReadRangeContinuousMillimeters(void)
   while ((val & 0x07) == 0)
   {
     i2cdevReadByte(I2Cx, devAddr, VL53L0X_RA_RESULT_INTERRUPT_STATUS, &val);
+    if ((val & 0x07) == 0)
+    {
+      // Relaxation delay when polling interrupt
+      vTaskDelay(M2T(1));
+    }
     if (checkTimeoutExpired())
     {
       did_timeout = true;

src/modules/src/position_estimator_altitude.c

@@ -45,7 +45,7 @@ struct selfState_s {
 static struct selfState_s state = {
   .estimatedZ = 0.0f,
   .velocityZ = 0.0f,
-  .estAlphaZrange = 0.93f,
+  .estAlphaZrange = 0.90f,
   .estAlphaAsl = 0.997f,
   .velocityFactor = 1.0f,
   .vAccDeadband = 0.04f,