added example sketch to find linear hall ADC center offsets, plus tweak to BLDCMotor for continuous sensor updating

Author: nanoparticle

examples/utils/sensor_test/linear_hall_sensors/find_raw_centers/find_raw_centers.ino

@@ -0,0 +1,62 @@
+/**
+ * An example to find the center offsets for both ADC channels used in the LinearHall sensor constructor
+ * Spin your motor through at least one full revolution to average out all of the variations in magnet strength.
+ */
+
+//Change these defines to match the analog input pins that your hall sensors are connected to
+#define LINEAR_HALL_CHANNEL_A 39
+#define LINEAR_HALL_CHANNEL_B 33
+
+
+//program variables
+int minA, maxA, minB, maxB, centerA, centerB;
+unsigned long timestamp;
+
+void setup() {
+  // monitoring port
+  Serial.begin(115200);
+
+  // initialise magnetic sensor hardware
+  pinMode(LINEAR_HALL_CHANNEL_A, INPUT);
+  pinMode(LINEAR_HALL_CHANNEL_B, INPUT);
+  
+  minA = analogRead(LINEAR_HALL_CHANNEL_A);
+  maxA = minA;
+  centerA = (minA + maxA) / 2;
+  minB = analogRead(LINEAR_HALL_CHANNEL_B);
+  maxB = minB;
+  centerB = (minB + maxB) / 2;
+
+  Serial.println("Sensor ready");
+  delay(1000);
+  timestamp = millis();
+}
+
+void loop() {
+  //read sensors and update variables
+  int tempA = analogRead(LINEAR_HALL_CHANNEL_A);
+  if (tempA < minA) minA = tempA;
+  if (tempA > maxA) maxA = tempA;
+  centerA = (minA + maxA) / 2;
+  int tempB = analogRead(LINEAR_HALL_CHANNEL_B);
+  if (tempB < minB) minB = tempB;
+  if (tempB > maxB) maxB = tempB;
+  centerB = (minB + maxB) / 2;
+
+  if (millis() > timestamp + 100) {
+    timestamp = millis();
+    // display the center counts, and max and min count
+    Serial.print("A:");
+    Serial.print(centerA);
+    Serial.print("\t, B:");
+    Serial.print(centerB);
+    Serial.print("\t, min A:");
+    Serial.print(minA);
+    Serial.print("\t, max A:");
+    Serial.print(maxA);
+    Serial.print("\t, min B:");
+    Serial.print(minB);
+    Serial.print("\t, max B:");
+    Serial.println(maxB);
+  }
+}

src/BLDCMotor.cpp

@@ -174,6 +174,7 @@ int BLDCMotor::alignSensor() {
     for (int i = 0; i <=500; i++ ) {
       float angle = _3PI_2 + _2PI * i / 500.0f;
       setPhaseVoltage(voltage_sensor_align, 0,  angle);
+	  sensor->update();
       _delay(2);
     }
     // take and angle in the middle
@@ -183,6 +184,7 @@ int BLDCMotor::alignSensor() {
     for (int i = 500; i >=0; i-- ) {
       float angle = _3PI_2 + _2PI * i / 500.0f ;
       setPhaseVoltage(voltage_sensor_align, 0,  angle);
+	  sensor->update();
       _delay(2);
     }
     sensor->update();