initial code for i2c communication with accelerometers
Dependencies: BLE_API mbed-dev nRF51822
Fork of capstone_i2c by
main.cpp
- Committer:
- cpadua
- Date:
- 2017-04-11
- Revision:
- 5:a52a03b6d13b
- Parent:
- 3:3d08e2045bde
File content as of revision 5:a52a03b6d13b:
/* Copyright (c) 2012-2014 RedBearLab Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #include "mbed.h" #include "wire.h" #define BLE_Nano //#define nRF_51822 #ifdef nRF_51822 #define SCL 28 #define SDA 29 #endif #ifdef BLE_Nano #define SCL 8 #define SDA 10 #endif #define DEV_ADDR 0xA0 #define ADDR_ONE 0x30 #define ADDR_TWO 0x32 #define AXIS_X 0x00 #define AXIS_Y 0x01 #define AXIS_Z 0x02 #define REG_OUT_X_L 0x28 #define REG_CTRL1 0x20 #define REG_CTRL4 0x23 #define REG_WHOAMI 0x0F #define RANGE_2G 0x00 #define DEVICE_ID 0x33 #define DATARATE_400HZ 0b0111 // 400Hz #define DATARATE_200HZ 0b0110 // 200Hz #define DATARATE_100HZ 0b0101 // 100Hz #define DATARATE_50HZ 0b0100 // 50Hz #define DATARATE_25HZ 0b0011 // 25Hz #define DATARATE_10HZ 0b0010 // 10Hz #define DATARATE_1HZ 0b0001 // 1Hz #define DATARATE_POWERDOWN 0 // Power down #define DATARATE_LOWPOWER_1K6HZ 0b1000 // Low power mode (1.6KHz) #define DATARATE_LOWPOWER_5KHZ 0b1001 // Low power mode (5KHz) / Normal power mode (1.25KHz) Serial pc(USBTX, USBRX); TwoWire Wire = TwoWire(NRF_TWI0); void AT24C512_WriteBytes(uint16_t addr, uint8_t *pbuf, uint16_t length, uint16_t i2cAddr) { Wire.beginTransmission(i2cAddr); int err = Wire.write( (uint8_t)addr ); Wire.write(pbuf, length); if (err != 0) { pc.printf("error on write write! %d\n", err); } uint8_t err8 = Wire.endTransmission(); if (err8 != 0) { pc.printf("error on write end transmission! %d\n", err8); } } void AT24C512_ReadBytes(uint16_t addr, uint8_t *pbuf, uint16_t length, uint16_t i2cAddr) { Wire.beginTransmission(i2cAddr); int err= Wire.write( (uint8_t)addr ); if (err != 0) { pc.printf("error on read write! %d\n", err); } uint8_t err8 = Wire.endTransmission(); if (err8 != 0) { pc.printf("error on read end transmission! %d\n", err8); } err8 = Wire.requestFrom(i2cAddr+1, length); if (err != 0) { pc.printf("error on read request from! %d\n", err8); } while( Wire.available() > 0 ) { *pbuf = Wire.read(); pbuf++; } } //Set the bit at index 'bit' to 'value' on 'input' and return uint8_t setBit(uint8_t input, uint8_t bit, uint8_t value) { uint8_t mask = 1 << bit; input &= ~mask; if (value == 1) { input |= mask; } return input; } uint16_t getAxis(uint16_t axis, uint16_t i2cAddr) { uint8_t base = REG_OUT_X_L + (2 * axis); uint8_t* low = new uint8_t[1]; uint8_t* high = new uint8_t[1]; AT24C512_ReadBytes(base, low, 1, i2cAddr); AT24C512_ReadBytes(base + 1, high, 1, i2cAddr); uint16_t res = low[0] | (high[0] << 8); return res; } void setRange(uint8_t range, uint16_t i2cAddr) { uint8_t* val = new uint8_t[1]; AT24C512_ReadBytes(REG_CTRL4, val, 1, i2cAddr);//get value from the register val[0] &= ~(0b110000); //zero out lowest 4 bits val[0] |= (range << 4); // write in our new range AT24C512_WriteBytes(REG_CTRL4, val, 1, i2cAddr); } //Set whether we want to use high resolution or not void setHighResolution(bool highRes, uint16_t i2cAddr) { uint8_t* val = new uint8_t[1]; AT24C512_ReadBytes(REG_CTRL4, val, 1, i2cAddr);//get value from the register uint8_t final; if (highRes) { final = setBit(val[0], 3, 1); } else { final = setBit(val[0], 3, 1); } val[0] = final; AT24C512_WriteBytes(REG_CTRL4, val, 1, i2cAddr); } void setAxisStatus(uint8_t axis, bool enable, uint16_t i2cAddr) { uint8_t* current = new uint8_t[1]; AT24C512_ReadBytes(REG_CTRL1, current, 1, i2cAddr);//get value from the register uint8_t final; if (enable == 1) { final = setBit(current[0], axis, 1); } else { final = setBit(current[0], axis, 0); } current[0] = final; AT24C512_WriteBytes(REG_CTRL1, current, 1, i2cAddr); } void setDataRate(uint8_t dataRate, uint16_t i2cAddr) { uint8_t* val = new uint8_t[1]; AT24C512_ReadBytes(REG_CTRL1, val, 1, i2cAddr); val[0] &= 0b1111; //mask off lower bits val[0] |= (dataRate << 4); AT24C512_WriteBytes(REG_CTRL1, val, 1, i2cAddr); } void setBDU(bool bdu, uint16_t i2cAddr) { uint8_t* val = new uint8_t[1]; AT24C512_ReadBytes(REG_CTRL4, val, 1, i2cAddr);//get value from the register uint8_t final; if (bdu == true) { final = setBit(val[0], 7, 1); } else { final = setBit(val[0], 7, 1); } val[0] = final; AT24C512_WriteBytes(REG_CTRL4, val, 1, i2cAddr); } uint16_t getX(uint16_t i2cAddr) { return getAxis(AXIS_X, i2cAddr); } uint16_t getY(uint16_t i2cAddr) { return getAxis(AXIS_Y, i2cAddr); } uint16_t getZ(uint16_t i2cAddr) { return getAxis(AXIS_Z, i2cAddr); } int main(void) { pc.baud(9600); wait(5); //Wire.begin(); Wire.begin(SCL, SDA, TWI_FREQUENCY_100K); uint8_t address; int error; int nDevices; pc.printf("Scanning...\n"); nDevices = 0; for(address = 1; address < 127; address++ ) { pc.printf("address: %x\n", address); // The i2c_scanner uses the return value of // the Write.endTransmisstion to see if // a device did acknowledge to the address. Wire.beginTransmission(address << 1); error = Wire.endTransmission(); pc.printf("Error Code: %d\n", error); if (error == 0) { pc.printf("I2C device found at address 0x%x\n", address); nDevices++; } else if (error==4) { pc.printf("Unknown error at address 0x%x\n", address); } } if (nDevices == 0) pc.printf("No I2C devices found\n"); else { pc.printf("%d I2C devices found\n", nDevices); } uint8_t* whoami = new uint8_t[1]; AT24C512_ReadBytes(REG_WHOAMI, whoami, 1, ADDR_ONE); pc.printf("Whoami: %d\r\n", whoami[1]); wait(15); setAxisStatus(AXIS_X, true, ADDR_ONE); setAxisStatus(AXIS_Y, true, ADDR_ONE); setAxisStatus(AXIS_Z, true, ADDR_ONE); setDataRate(DATARATE_400HZ, ADDR_ONE); setHighResolution(true, ADDR_ONE); setBDU(true, ADDR_ONE); setRange(RANGE_2G, ADDR_ONE); setAxisStatus(AXIS_X, true, ADDR_TWO); setAxisStatus(AXIS_Y, true, ADDR_TWO); setAxisStatus(AXIS_Z, true, ADDR_TWO); setDataRate(DATARATE_400HZ, ADDR_ONE); setHighResolution(true, ADDR_TWO); setBDU(true, ADDR_TWO); setRange(RANGE_2G, ADDR_TWO); wait(0.1); while(1) { pc.printf("Read data from AT24C512 \r\n"); uint16_t x1 = getX(ADDR_ONE); uint16_t y1 = getY(ADDR_ONE); uint16_t z1 = getZ(ADDR_ONE); uint16_t x2 = getX(ADDR_TWO); uint16_t y2 = getY(ADDR_TWO); uint16_t z2 = getZ(ADDR_TWO); pc.printf("Accel one: x %d y %d z %d\r\n", x1, y1, z1); pc.printf("Accel two: x %d y %d z %d\r\n", x2, y2, z2); pc.printf("\r\n"); wait(1); } }