finally I have done to implement that ADXL345 can throw data over BLE using nRF UART app service with this code. now my problem is how to change 2's complement ADXL345 data to array of string/character.
here it is the data using nRF51 uart app
so how to fix random character to array of string number. like the number of sensor measurenment.
here this code:
#include "ADXL345_I2C.h"
#include "mbed.h"
#include "ble/BLE.h"
#include "ble/services/UARTService.h"
#include "Serial.h"
#define NEED_CONSOLE_OUTPUT 1 /* Set this if you need debug messages on the console;
* it will have an impact on code-size and power consumption. */
#if NEED_CONSOLE_OUTPUT
#define DEBUG(...) { printf(__VA_ARGS__); }
#else
#define DEBUG(...) /* nothing */
#endif /* #if NEED_CONSOLE_OUTPUT */
ADXL345_I2C accelerometer(p30, p7);
BLEDevice ble;
DigitalOut led1(LED1);
Serial uart1(USBTX,USBRX);
UARTService *uartServicePtr;
void disconnectionCallback(const Gap::DisconnectionCallbackParams_t *params)
{
DEBUG("Disconnected!\n\r");
DEBUG("Restarting the advertising process\n\r");
ble.startAdvertising();
}
void connectionCallback(const Gap::ConnectionCallbackParams_t *params)
{
DEBUG("Connected!\n\r");
}
uint8_t b[40]={'a','d','q','w'};
void onDataWritten(const GattWriteCallbackParams *params)
{
if ((uartServicePtr != NULL) && (params->handle == uartServicePtr->getTXCharacteristicHandle()))
{
uint16_t bytesRead = params->len;
DEBUG("received %u bytes %s\n\r", bytesRead,params->data);
/*uint16_t bytesRead = params->len;
DEBUG("received %u bytes\n\r", bytesRead);
ble.updateCharacteristicValue(uartServicePtr->getRXCharacteristicHandle(), params->data, bytesRead);*/
}
}
void periodicCallback(void)
{
led1 = !led1;
}
int main() {
uart1.baud(9600);
int readings[3] = {0, 0, 0};
pc.printf("Starting ADXL345 test...\n");
wait(.001);
pc.printf("Device ID is: 0x%02x\n", accelerometer.getDeviceID());
wait(.001);
//Go into standby mode to configure the device.
accelerometer.setPowerControl(0x00);
//Full resolution, +/-16g, 4mg/LSB.
accelerometer.setDataFormatControl(0x0B);
//3.2kHz data rate.
accelerometer.setDataRate(ADXL345_3200HZ);
//Measurement mode.
accelerometer.setPowerControl(0x08);
led1 = 1;
uart1.baud(9600);
Ticker ticker;
ticker.attach(periodicCallback, 1);
DEBUG("Initialising the nRF51822\n\r");
ble.init();
ble.onDisconnection(disconnectionCallback);
ble.onConnection(connectionCallback);
ble.onDataWritten(onDataWritten);
/* setup advertising */
ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED);
ble.setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED);
ble.accumulateAdvertisingPayload(GapAdvertisingData::SHORTENED_LOCAL_NAME,
(const uint8_t *)"BLE UART", sizeof("BLE UART") - 1);
ble.accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_128BIT_SERVICE_IDS,
(const uint8_t *)UARTServiceUUID_reversed, sizeof(UARTServiceUUID_reversed));
ble.setAdvertisingInterval(1000); /* 1000ms; in multiples of 0.625ms. */
ble.startAdvertising();
UARTService uartService(ble);
uartServicePtr = &uartService;
while (1)
{
ble.waitForEvent();
wait(0.1);
accelerometer.getOutput(readings);
uart1.printf("%i, %i, %i\n", (int16_t)readings[0], (int16_t)readings[1], (int16_t)readings[2]);
ble.updateCharacteristicValue(uartServicePtr->getRXCharacteristicHandle(), (const uint8_t*)readings[0], sizeof(readings),false);
ble.updateCharacteristicValue(uartServicePtr->getRXCharacteristicHandle(), (const uint8_t*)readings[1], sizeof(readings),false);
ble.updateCharacteristicValue(uartServicePtr->getRXCharacteristicHandle(), (const uint8_t*)readings[2], sizeof(readings),false);
}
}
