Revision 3:b9783107a8c4, committed 2019-09-30

Comitter:

f3d

Date:

Mon Sep 30 11:59:42 2019 +0000

Parent:

2:4871b5ad7938

Commit message:

Magnetometer for the LSM303

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/magservice.h	Mon Sep 30 11:59:42 2019 +0000
@@ -0,0 +1,101 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __BLE_MAG_SERVICE_H__
+#define __BLE_MAG_SERVICE_H__
+#include <mbed.h>
+// Accelerometer : LSM303
+//I2C i2c(P0_30, P0_0); // SDA is on P0_30, SCL is on P0_0
+const int LSM303_ADDRESS = (0x19<<1); 
+//const int MMA8653_ID = 0x5a;
+class MAGService {
+public:
+    const static uint16_t MAG_SERVICE_UUID = 0xfff3;
+    const static uint16_t MAG_X_CHARACTERISTIC_UUID = 0x1;
+    const static uint16_t MAG_Y_CHARACTERISTIC_UUID = 0x2;
+    const static uint16_t MAG_Z_CHARACTERISTIC_UUID = 0x3;
+
+    MAGService(BLEDevice &_ble, int16_t initialValueForMAGCharacteristic) :
+        ble(_ble), MagX(MAG_X_CHARACTERISTIC_UUID, &initialValueForMAGCharacteristic),MagY(MAG_Y_CHARACTERISTIC_UUID, &initialValueForMAGCharacteristic),MagZ(MAG_Z_CHARACTERISTIC_UUID, &initialValueForMAGCharacteristic)
+    {
+        GattCharacteristic *charTable[] = {&MagX,&MagY,&MagZ};
+        GattService         MagService(MAG_SERVICE_UUID, charTable, sizeof(charTable) / sizeof(GattCharacteristic *));
+        ble.addService(MagService);
+        // Wake the accelerometer from sleep mode by writing disabling low power mode, setting freq to 10Hz and enabling all three axes
+        char Data[8]; // Declare a buffer for data transfer    
+        int Status;
+        Data[0]=0x20;   // wake up LSM303 (max speed, all accel channels)
+        Data[1]=0x77;
+        Status = i2c.write(LSM303_ADDRESS,Data,2);  // Write data to register   
+       
+        Data[0]=0x23;   // enable high resolution mode
+        Data[1]=0x0e; 
+        Status = i2c.write(LSM303_ADDRESS,Data,2);  // Write data to register   
+    }
+
+    GattAttribute::Handle_t getValueHandle() const {
+        return MagX.getValueHandle();
+    }
+    void updateMagX(uint16_t newValue) {
+        ble.gattServer().write(MagX.getValueHandle(), (uint8_t *)&newValue, sizeof(uint16_t));
+    }
+    void updateMagY(uint16_t newValue) {
+        ble.gattServer().write(MagY.getValueHandle(), (uint8_t *)&newValue, sizeof(uint16_t));
+    }
+    void updateMagZ(uint16_t newValue) {
+        ble.gattServer().write(MagZ.getValueHandle(), (uint8_t *)&newValue, sizeof(uint16_t));
+    }
+    void poll()
+    {
+        char Data[8]; // Declare a buffer for data transfer    
+        int Status;
+        int16_t X;
+                         
+        // Modify to suit your chip:
+        // Goal get X,Y and Z readings off magnetometer.
+        Data[0]=0x80 + 0x28; // Register number 0x28 has the X data (2 bytes)
+        Status = i2c.write(LSM303_ADDRESS,Data,1,true);  // Write register number
+        Status = i2c.read(LSM303_ADDRESS,Data,2); // Read register contents
+        X = Data[1];
+        X = (X << 8) + Data[0];
+        
+        int16_t Y;
+        Data[0]=0x80 + 0x2a; // Register number 0x2a has the Y data (2 bytes)
+        Status = i2c.write(LSM303_ADDRESS,Data,1,true);  // Write register number
+        Status = i2c.read(LSM303_ADDRESS,Data,2); // Read register contents
+        Y = Data[1];
+        Y = (Y << 8) + Data[0];
+        
+        int16_t Z;
+        Data[0]=0x80 + 0x2c; // Register number 0x2c has the Z data (2 bytes)
+        Status = i2c.write(LSM303_ADDRESS,Data,1,true);  // Write register number
+        Status = i2c.read(LSM303_ADDRESS,Data,2); // Read register contents
+        Z = Data[1];
+        Z = (Z << 8) + Data[0];
+        
+        updateMagX(X);
+        updateMagY(Y);
+        updateMagZ(Z);        
+        
+    }
+private:
+    BLEDevice &ble;
+    ReadOnlyGattCharacteristic<int16_t>  MagX;
+    ReadOnlyGattCharacteristic<int16_t>  MagY;
+    ReadOnlyGattCharacteristic<int16_t>  MagZ;
+};
+
+#endif /* #ifndef __BLE_ACCEL_SERVICE_H__ */

--- a/main.cpp	Mon Sep 30 10:38:33 2019 +0000
+++ b/main.cpp	Mon Sep 30 11:59:42 2019 +0000
@@ -19,6 +19,7 @@
 #include "LEDService.h"
 #include "ButtonAService.h"
 #include "accelService.h"
+#include "magservice.h"
 
 /* 
  * All the LEDs on the micro:bit are part of the LED Matrix,
@@ -32,12 +33,12 @@
 
 const static char     DEVICE_NAME[] = "front1";
 //static const uint16_t uuid16_list[] = {LEDService::LED_SERVICE_UUID,ACCELService::ACCEL_SERVICE_UUID,ButtonAService::BUTTONA_SERVICE_UUID};
-static const uint16_t uuid16_list[] = {ACCELService::ACCEL_SERVICE_UUID};
+static const uint16_t uuid16_list[] = {0xA012,0xFFF3};
 
 LEDService *ledServicePtr;
 ButtonAService * btnAServicePtr;
 ACCELService *AccelServicePtr;
-
+MAGService * MagServicePtr;
 Ticker ticker;
 
 void disconnectionCallback(const Gap::DisconnectionCallbackParams_t *params)
@@ -50,6 +51,7 @@
     
     btnAServicePtr->poll();
     AccelServicePtr->poll();
+    MagServicePtr->poll();
     if (btnAServicePtr->GetButtonAState())
         alivenessLED = 1;
     else
@@ -109,6 +111,7 @@
     btnAServicePtr = new ButtonAService(ble);
     int16_t Tst=0;
     AccelServicePtr = new ACCELService(ble,Tst);
+    MagServicePtr = new MAGService(ble,Tst);
     /* setup advertising */
     ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE);
     ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_16BIT_SERVICE_IDS, (uint8_t *)uuid16_list, sizeof(uuid16_list));