File content as of revision 14:033ae98fca47:

/* 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.
 */

#include "mbed.h"
#include "ble/BLE.h"

#include "ADXL345.h"
#include "ble/services/UARTService.h"

#define NEED_CONSOLE_OUTPUT 0 /* 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 */

BLEDevice  ble;
DigitalOut led1(LED1);

UARTService *uartServicePtr;
ADXL345 accelerometer(p5, p6, p7, p8); // (SDA, SDO, SCL, CS);
Serial pc(USBTX, USBRX); //For raw data

int readings[3] = {0, 0, 0};
float mag_lsb;

float x,y,z,mag_g;
float acc_readings[6][3];
float calc_offsets[3];
const float g=9.80665;
const float g_mm=g*1000;
const float acc_res_mg=3.9063; //acc resolution mg/LSB

int8_t offset2_8bit_int[3]={0,0,0};
char offset2_8bit_char[3];

float mg_offsets[3]={0.0,0.0,0.0}; //fine offsets in mg's which cannot be corrected by adxl

void acc_read();
void display_acc();
void acc_store_offsets();   
int sign(float input); 
void display_fine_acc();


void disconnectionCallback(const Gap::DisconnectionCallbackParams_t *params)
{
    DEBUG("Disconnected!\n\r");
    DEBUG("Restarting the advertising process\n\r");
    ble.startAdvertising();
}

void onDataWritten(const GattWriteCallbackParams *params)
{
    if ((uartServicePtr != NULL) && (params->handle == uartServicePtr->getTXCharacteristicHandle())) {
        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(void)
{
    led1 = 1;
    Ticker ticker;
    ticker.attach(periodicCallback, 1);

    DEBUG("Initialising the nRF51822\n\r");
    ble.init();
    ble.onDisconnection(disconnectionCallback);
    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 (true) {
        ble.waitForEvent();
    }
    
    pc.baud(9600); //set baud rate for USB serial to 921600bps
    
    pc.printf("Starting ADXL345 test...\n");
    pc.printf("Device ID is: 0x%02x\n", accelerometer.getDevId());
        

    //Go into standby mode to configure the device.
    accelerometer.setPowerControl(0x00);

    //Full resolution, +/-4g, 3.9mg/LSB.
    accelerometer.setDataFormatControl(0x0B);

    //3.2kHz data rate.
    accelerometer.setDataRate(ADXL345_3200HZ);

    pc.printf("Axes offsets: ");
    pc.printf("X: %d \t",accelerometer.getOffset(0x00));
    pc.printf("Y: %d \t",accelerometer.getOffset(0x01));
    pc.printf("Z: %d \n",accelerometer.getOffset(0x02));

    //Measurement mode.
    accelerometer.setPowerControl(0x08);
    
    pc.printf("Current IMU reading: \n");
    acc_read();
    display_acc();
    
    pc.printf("\nTo Calculate new offsets IMU needs to be re-oriented 12 times,\n Send 'R' when ready...\n\n");
    while(pc.getc() != 'R') {}
    
    pc.printf("Resetting current offsets... \n");
    acc_store_offsets();
    
    {
        pc.printf("Okay, ready for first coarse reading set,\n Put IMU with +Z pointing up, then press 'R' when ready \n");
        while(pc.getc() != 'R') {}
        wait(0.1);
        for(int n=0; n<10; n++)
        {
        wait(0.1); 
        acc_read();
        acc_readings[4][0]+=x;
        acc_readings[4][1]+=y;
        acc_readings[4][2]+=z;
        }  
        //display_acc();
        pc.printf("\n");
    
        pc.printf("Put IMU with -Z pointing up, then press 'R' when ready \n");
        while(pc.getc() != 'R') {}
        wait(0.1); 
        for(int n=0; n<10; n++)
        {
        wait(0.1);
        acc_read();
        acc_readings[5][0]+=x;
        acc_readings[5][1]+=y;
        acc_readings[5][2]+=z;
        }
        //display_acc();
        pc.printf("\n");
    
        
        pc.printf("Put IMU with +Y pointing up, then press 'R' when ready \n");
        while(pc.getc() != 'R') {}
        wait(0.1); 
        for(int n=0; n<10; n++)
        {
        wait(0.1);
        acc_read();
        acc_readings[2][0]+=x;
        acc_readings[2][1]+=y;
        acc_readings[2][2]+=z;
        }
        //display_acc();
        pc.printf("\n");
        
        pc.printf("Put IMU with -Y pointing up, then press 'R' when ready \n");
        while(pc.getc() != 'R') {}
        wait(0.1); 
        for(int n=0; n<10; n++)
        {
        wait(0.1);
        acc_read();
        acc_readings[3][0]+=x;
        acc_readings[3][1]+=y;
        acc_readings[3][2]+=z;
        }
        //display_acc();
        pc.printf("\n");
        
        pc.printf("Put IMU with +X pointing up, then press 'R' when ready \n");
        while(pc.getc() != 'R') {}
        wait(0.1); 
        for(int n=0; n<10; n++)
        {
        wait(0.1);
        acc_read();
        acc_readings[0][0]+=x;
        acc_readings[0][1]+=y;
        acc_readings[0][2]+=z;
        }
        //display_acc();
        pc.printf("\n");
        
        pc.printf("Put IMU with -X pointing up, then press 'R' when ready \n");
        while(pc.getc() != 'R') {}
        wait(0.1); 
        for(int n=0; n<10; n++)
        {
        wait(0.1);
        acc_read();
        acc_readings[1][0]+=x;
        acc_readings[1][1]+=y;
        acc_readings[1][2]+=z;
        }
        //display_acc();
        pc.printf("\n");
    }
    
     calc_offsets[0] = (acc_readings[0][0] - acc_readings[1][0])/(10*2*acc_res_mg) - 256;
     calc_offsets[1] = (acc_readings[2][1] - acc_readings[3][1])/(10*2*acc_res_mg) - 256;
     calc_offsets[2] = (acc_readings[4][2] - acc_readings[5][2])/(10*2*acc_res_mg) - 256;
     
    calc_offsets[0] = calc_offsets[0]/4; //convert to 8 bit scale 15.6 mg/LSB
    calc_offsets[1] = calc_offsets[1]/4; //convert to 8 bit scale 15.6 mg/LSB
    calc_offsets[2] = calc_offsets[2]/4; //convert to 8 bit scale 15.6 mg/LSB
    
    pc.printf("Coarse calibration complete, offsets in 8bit scale (15.6mg/LSB) are: \t");
    pc.printf("X: %.1f, Y: %.1f, Z: %.1f", calc_offsets[0], calc_offsets[1], calc_offsets[2]);


    pc.printf("\n Apply offsets to ADXL345? Press Y to continue... \n");
    while(pc.getc() != 'Y') {}
    acc_store_offsets();    
    pc.printf("\n Done! ADXL 345 is now calibrated!!!\n\n New offsets are: \n");
        pc.printf("X: %d \t",accelerometer.getOffset(0x00));
        pc.printf("Y: %d \t",accelerometer.getOffset(0x01));
        pc.printf("Z: %d \n",accelerometer.getOffset(0x02));
    pc.printf("\n");
    wait(1);
    
    
    {
        float mg_offsets_x[2]={0,0};
        float mg_offsets_y[2]={0,0};
        float mg_offsets_z[2]={0,0};
        
        pc.printf("Ready for fine reading set,\n Put IMU with +Z pointing up, then press 'R' when ready \n");
        while(pc.getc() != 'R') {}
        wait(0.1);
        for(int n=0; n<10; n++)
        {
        wait(0.1); 
        acc_read();
        mg_offsets_z[0]+=z;
        }
        pc.printf("\n");
        
        pc.printf("Put IMU with -Z pointing up, then press 'R' when ready \n");
        while(pc.getc() != 'R') {}
        wait(0.1); 
        for(int n=0; n<10; n++)
        {
        wait(0.1); 
        acc_read();
        mg_offsets_z[1]+=z;
        }
        pc.printf("\n");
        
        pc.printf("Put IMU with +Y pointing up, then press 'R' when ready \n");
        while(pc.getc() != 'R') {}
        wait(0.1); 
        for(int n=0; n<10; n++)
        {
        wait(0.1); 
        acc_read();
        mg_offsets_y[0]+=y;
        }
        pc.printf("\n");
        
        pc.printf("Put IMU with -Y pointing up, then press 'R' when ready \n");
        while(pc.getc() != 'R') {}
        wait(0.1); 
        for(int n=0; n<10; n++)
        {
        wait(0.1); 
        acc_read();
        mg_offsets_y[1]+=y;
        }
        pc.printf("\n");
        
        pc.printf("Put IMU with +X pointing up, then press 'R' when ready \n");
        while(pc.getc() != 'R') {}
        wait(0.1); 
        for(int n=0; n<10; n++)
        {
        wait(0.1); 
        acc_read();
        mg_offsets_x[0]+=x;
        }
        pc.printf("\n");
        
        pc.printf("Put IMU with -X pointing up, then press 'R' when ready \n");
        while(pc.getc() != 'R') {}
        wait(0.1); 
        for(int n=0; n<10; n++)
        {
        wait(0.1); 
        acc_read();
        mg_offsets_x[1]+=x;
        }
        pc.printf("\n");
        
        mg_offsets[0] = ((mg_offsets_x[0]/10 - 1000) + (1000 + mg_offsets_x[1]/10))/2;
        mg_offsets[1] = ((mg_offsets_y[0]/10 - 1000) + (1000 + mg_offsets_y[1]/10))/2;
        mg_offsets[2] = ((mg_offsets_z[0]/10 - 1000) + (1000 + mg_offsets_z[1]/10))/2;
            
        pc.printf("Fine calibration complete, offsets in mg are: \t");
            pc.printf("X: %f \t",mg_offsets[0]);
            pc.printf("Y: %f \t",mg_offsets[1]);
            pc.printf("Z: %f \n",mg_offsets[2]);
    }
    
    wait(5);
    
    while(1)
    {
        wait(0.25);
        pc.printf("\nCurrent IMU reading:\n");
        acc_read();
        display_fine_acc();
    }
}


void acc_read()
{
    accelerometer.getOutput(readings);

    x=(int16_t)readings[0] * acc_res_mg;
    y=(int16_t)readings[1] * acc_res_mg;
    z=(int16_t)readings[2] * acc_res_mg;
        
    mag_g = sqrt(pow(x,2)+pow(y,2)+pow(z,2));
    mag_lsb = mag_g/acc_res_mg;
}

void display_acc()
{
    pc.printf("Raw: %i, %i, %i : %.1f\n", (int16_t)readings[0], (int16_t)readings[1], (int16_t)readings[2], mag_lsb); //Raw data
    pc.printf("mG's: %.3f, %.3f, %.3f : %.4f\n", x, y, z, mag_g); //In G's data
}

void display_fine_acc()
{
    x -= mg_offsets[0];
    y -= mg_offsets[1];
    z -= mg_offsets[2];
    
    readings[0] -= (int16_t) (mg_offsets[0]/acc_res_mg);
    readings[1] -= (int16_t) (mg_offsets[1]/acc_res_mg);
    readings[2] -= (int16_t) (mg_offsets[2]/acc_res_mg);
    
    mag_g = sqrt(pow(x,2)+pow(y,2)+pow(z,2));
    mag_lsb = mag_g/acc_res_mg;
    
    pc.printf("Raw: %i, %i, %i : %.1f\n", (int16_t)readings[0], (int16_t)readings[1], (int16_t)readings[2], mag_lsb); //Raw data
    pc.printf("mG's: %.3f, %.3f, %.3f : %.4f\n", x, y, z, mag_g); //In G's data
    pc.printf("Fine offset in mG's: %.3f, %.3f, %.3f\n", mg_offsets[0], mg_offsets[1], mg_offsets[2]); //In G's data
}

void acc_store_offsets()
{
    for(int v=0; v<=2; v++)
    {
        offset2_8bit_int[v] = (int8_t) calc_offsets[v];
        if(abs(calc_offsets[v] - offset2_8bit_int[v]) >= 0.5)
            offset2_8bit_int[v] += (int8_t) sign(calc_offsets[v]);
        
        offset2_8bit_int[v] = ~offset2_8bit_int[v];
        offset2_8bit_int[v] += 1;
        
        offset2_8bit_char[v] = offset2_8bit_int[v];
    }
    
        //Go into standby mode to configure the device.
        accelerometer.setPowerControl(0x00);
    
        accelerometer.setOffset(0x00, offset2_8bit_char[0]);
        wait(0.1); //wait a bit
        
        accelerometer.setOffset(0x01, offset2_8bit_char[1]);
        wait(0.1); //wait a bit
        
        accelerometer.setOffset(0x02, offset2_8bit_char[2]);
        wait(0.1); //wait a bit
        
        //Measurement mode.
        accelerometer.setPowerControl(0x08);
}

int sign(float input)
{
    if (input<0)
        return -1;
    else if(input>0)
        return 1;
    else
        return 0;
}