NanoMotorCarrier: add battery charge API

Author: facchinm

src/MotorController.cpp

@@ -18,6 +18,13 @@
 #include "Common.h"
 #include "Wire.h"
 
+#define PMIC_ADDRESS  0x6B
+#define PMIC_REG00    0x00
+#define PMIC_REG01    0x01
+#define PMIC_REG02    0x02
+#define PMIC_REG04    0x04
+#define PMIC_REG05    0x05
+
 String mc::MotorController::getFWVersion() {
   char ret[5];
   getData(GET_VERSION, (uint8_t*)ret);
@@ -42,6 +49,14 @@ float mc::MotorController::getTemperature() {
 
 int mc::MotorController::begin() {
   Wire.begin();
+
+  // PMIC initialization raw APIs: are sused to initialize the
+  // PMIC when used with nano 33 iot
+#ifdef ARDUINO_SAMD_NANO_33_IOT
+   Serial.println("Board: Nano 33 IoT");
+   enable_battery_charging();
+   Serial.println("Charging enabled....");
+#endif
   String version = getFWVersion();
   if (version.c_str()[0] == '0') {
     return 1;
@@ -59,4 +74,27 @@ int mc::MotorController::getFreeRam() {
   int ret;
   getData(GET_FREE_RAM, (uint8_t*)&ret);
   return ret;
+}
+
+void mc::MotorController::enable_battery_charging() {
+  Wire.beginTransmission(PMIC_ADDRESS);
+  Wire.write(PMIC_REG00);
+  Wire.write(0x06); // min sys voltage 3.88V + max input current 2.0 A
+  Wire.endTransmission();
+  Wire.beginTransmission(PMIC_ADDRESS);
+  Wire.write(PMIC_REG01);
+  Wire.write(0x1B); // Charge Battery + Minimum System Voltage 3.5V
+  Wire.endTransmission();
+  Wire.beginTransmission(PMIC_ADDRESS);
+  Wire.write(PMIC_REG02);
+  Wire.write(0x00); // Charge current  512 mA
+  Wire.endTransmission();
+  Wire.beginTransmission(PMIC_ADDRESS);
+  Wire.write(PMIC_REG04);
+  Wire.write(0x9E); // Charge Voltage Limit 4.128V
+  Wire.endTransmission();
+  Wire.beginTransmission(PMIC_ADDRESS);
+  Wire.write(PMIC_REG05);
+  Wire.write(0x8A); // Enable Battery Charge termination + disable watchdog
+  Wire.endTransmission();
 }

src/MotorController.h

@@ -32,6 +32,9 @@ class MotorController {
     uint8_t getIrqStatus();
     int getFreeRam();
     volatile uint8_t irq_status;
+  private:
+    void enable_battery_charging();
+
 };
 }