First integration of the motion sensor (bma 421) : step counting + wake on wrist rotation + app to see the value of the 3 axis in "real time".

src/drivers/Bma421.h

@@ -0,0 +1,43 @@
+#pragma once
+#include <drivers/Bma421_C/bma4_defs.h>
+
+namespace Pinetime {
+  namespace Drivers {
+    class TwiMaster;
+    class Bma421 {
+    public:
+      struct Values {
+        uint32_t steps;
+        int16_t x;
+        int16_t y;
+        int16_t z;
+      };
+      Bma421(TwiMaster& twiMaster, uint8_t twiAddress);
+      Bma421(const Bma421&) = delete;
+      Bma421& operator=(const Bma421&) = delete;
+      Bma421(Bma421&&) = delete;
+      Bma421& operator=(Bma421&&) = delete;
+
+      void Init();
+      void Reset();
+      Values Process();
+
+      void Read(uint8_t registerAddress, uint8_t *buffer, size_t size);
+      void Write(uint8_t registerAddress, const uint8_t *data, size_t size);
+
+      void OnIrq();
+
+      uint32_t GetNbInterrupts() const {return nbInterrupts;}
+
+    private:
+      TwiMaster& twiMaster;
+      uint8_t twiAddress;
+
+      struct bma4_dev bma;
+      struct bma4_accel_config accel_conf;
+      static constexpr uint8_t deviceAddress = 0x18;
+
+      uint32_t nbInterrupts = 0;
+    };
+  }
+}