microbit: First draft of Magnetometer BLE service

This commit is contained in:
Joe Finney 2015-09-19 21:03:36 +01:00
parent ae0e5611c3
commit 1e71169550
2 changed files with 154 additions and 0 deletions

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#ifndef MICROBIT_MAGNETOMETER_SERVICE_H
#define MICROBIT_MAGNETOMETER_SERVICE_H
#include "MicroBit.h"
// UUIDs for our service and characteristics
extern const uint8_t MicroBitMagnetometerServiceUUID[];
extern const uint8_t MicroBitMagnetometerServiceDataUUID[];
extern const uint8_t MicroBitMagnetometerServiceBearingUUID[];
extern const uint8_t MicroBitMagnetometerServicePeriodUUID[];
/**
* Class definition for a MicroBit BLE Magnetometer Service.
* Provides access to live magnetometer data via BLE, and provides basic configuration options.
*/
class MicroBitMagnetometerService
{
public:
/**
* Constructor.
* Create a representation of the MagnetometerService
* @param _ble The instance of a BLE device that we're running on.
*/
MicroBitMagnetometerService(BLEDevice &_ble);
private:
/**
* Callback. Invoked when any of our attributes are written via BLE.
*/
void onDataWritten(const GattWriteCallbackParams *params);
/**
* Magnetometer update callback
*/
void magnetometerUpdate(MicroBitEvent e);
// Bluetooth stack we're running on.
BLEDevice &ble;
// memory for our 8 bit control characteristics.
uint16_t magnetometerDataCharacteristicBuffer[3];
uint16_t magnetometerBearingCharacteristicBuffer;
uint16_t magnetometerPeriodCharacteristicBuffer;
// Handles to access each characteristic when they are held by Soft Device.
GattAttribute::Handle_t magnetometerDataCharacteristicHandle;
GattAttribute::Handle_t magnetometerBearingCharacteristicHandle;
GattAttribute::Handle_t magnetometerPeriodCharacteristicHandle;
};
#endif

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/**
* Class definition for the custom MicroBit Magnetometer Service.
* Provides a BLE service to remotely read the state of the magnetometer, and configure its behaviour.
*/
#include "MicroBit.h"
#include "ble/UUID.h"
#include "MicroBitMagnetometerService.h"
/**
* Constructor.
* Create a representation of the MagnetometerService
* @param _ble The instance of a BLE device that we're running on.
*/
MicroBitMagnetometerService::MicroBitMagnetometerService(BLEDevice &_ble) :
ble(_ble)
{
// Create the data structures that represent each of our characteristics in Soft Device.
GattCharacteristic magnetometerDataCharacteristic(MicroBitMagnetometerServiceDataUUID, (uint8_t *)magnetometerDataCharacteristicBuffer, 0,
sizeof(magnetometerDataCharacteristicBuffer), GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_READ | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY);
GattCharacteristic magnetometerBearingCharacteristic(MicroBitMagnetometerServiceBearingUUID, (uint8_t *)magnetometerBearingCharacteristicBuffer, 0,
sizeof(magnetometerBearingCharacteristicBuffer), GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_READ | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY);
GattCharacteristic magnetometerPeriodCharacteristic(MicroBitMagnetometerServicePeriodUUID, (uint8_t *)magnetometerPeriodCharacteristicBuffer, 0,
sizeof(magnetometerPeriodCharacteristicBuffer),
GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_READ | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_WRITE_WITHOUT_RESPONSE);
// Initialise our characteristic values.
magnetometerDataCharacteristicBuffer[0] = 0;
magnetometerDataCharacteristicBuffer[1] = 0;
magnetometerDataCharacteristicBuffer[2] = 0;
magnetometerBearingCharacteristicBuffer = 0;
magnetometerPeriodCharacteristicBuffer = 0;
GattCharacteristic *characteristics[] = {&magnetometerDataCharacteristic, &magnetometerBearingCharacteristic, &magnetometerPeriodCharacteristic};
GattService service(MicroBitMagnetometerServiceUUID, characteristics, sizeof(characteristics) / sizeof(GattCharacteristic *));
ble.addService(service);
magnetometerDataCharacteristicHandle = magnetometerDataCharacteristic.getValueHandle();
magnetometerBearingCharacteristicHandle = magnetometerBearingCharacteristic.getValueHandle();
magnetometerPeriodCharacteristicHandle = magnetometerPeriodCharacteristic.getValueHandle();
ble.updateCharacteristicValue(magnetometerDataCharacteristicHandle, (const uint8_t *)&magnetometerDataCharacteristicBuffer, sizeof(magnetometerDataCharacteristicBuffer));
ble.updateCharacteristicValue(magnetometerBearingCharacteristicHandle, (const uint8_t *)&magnetometerDataCharacteristicBuffer, sizeof(magnetometerDataCharacteristicBuffer));
ble.updateCharacteristicValue(magnetometerPeriodCharacteristicHandle, (const uint8_t *)&magnetometerPeriodCharacteristicBuffer, sizeof(magnetometerPeriodCharacteristicBuffer));
ble.onDataWritten(this, &MicroBitMagnetometerService::onDataWritten);
uBit.MessageBus.listen(MICROBIT_ID_COMPASS, MICROBIT_COMPASS_EVT_DATA_UPDATE, this, &MicroBitMagnetometerService::magnetometerUpdate, MESSAGE_BUS_LISTENER_NONBLOCKING | MESSAGE_BUS_LISTENER_URGENT);
}
/**
* Callback. Invoked when any of our attributes are written via BLE.
*/
void MicroBitMagnetometerService::onDataWritten(const GattWriteCallbackParams *params)
{
if (params->handle == magnetometerPeriodCharacteristicHandle && params->len >= sizeof(magnetometerPeriodCharacteristicBuffer))
{
magnetometerPeriodCharacteristicBuffer = *((uint8_t *)params->data);
uBit.compass.setPeriod(magnetometerPeriodCharacteristicBuffer);
}
}
/**
* Magnetometer update callback
*/
void MicroBitMagnetometerService::magnetometerUpdate(MicroBitEvent e)
{
magnetometerDataCharacteristicBuffer[0] = uBit.compass.getX();
magnetometerDataCharacteristicBuffer[1] = uBit.compass.getY();
magnetometerDataCharacteristicBuffer[2] = uBit.compass.getZ();
magnetometerBearingCharacteristicBuffer = (uint16_t) uBit.compass.bearing();
ble.gattServer().notify(magnetometerDataCharacteristicHandle,(uint8_t *)magnetometerDataCharacteristicBuffer, sizeof(magnetometerDataCharacteristicBuffer));
ble.gattServer().notify(magnetometerDataCharacteristicHandle,(uint8_t *)magnetometerBearingCharacteristicBuffer, sizeof(magnetometerDataCharacteristicBuffer));
}
const uint8_t MicroBitMagnetometerServiceUUID[] = {
0xe9,0x5d,0xf2,0xd8,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
};
const uint8_t MicroBitMagnetometerServiceDataUUID[] = {
0xe9,0x5d,0xfb,0x11,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
};
const uint8_t MicroBitMagnetometerServicePeriodUUID[] = {
0xe9,0x5d,0x38,0x6c,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
};
// TODO: Need an assigned UUID from martin here..
const uint8_t MicroBitMagnetometerServiceBearingUUID[] = {
0xe9,0x5d,0xde,0xad,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
};