Kenji Arai
Analog Devices 3-axis accelerometer. I2C interface
Diff: ADXL345.cpp
- Revision:
- 0:21a3f84ad1c9
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/ADXL345.cpp Sat Sep 23 22:21:33 2017 +0000
@@ -0,0 +1,346 @@
+/*
+ * mbed library program
+ * ADXL345: 3-axis accelerometer, made by Analog Devices
+ * http://www.analog.com/static/imported-files/data_sheets/ADXL345.pdf
+ *
+ * Copyright (c) 2017 Kenji Arai / JH1PJL
+ * http://www.page.sannet.ne.jp/kenjia/index.html
+ * http://mbed.org/users/kenjiArai/
+ * Modify: August 13th, 2017
+ * Revised: September 23rd, 2017
+ *
+ */
+
+#include "ADXL345.h"
+
+// definition for Nomalization
+#define ADXL345_SENSITIVITY_2G 4.0f
+#define ADXL345_SENSITIVITY_4G 8.0f
+#define ADXL345_SENSITIVITY_8G 16.0f
+#define ADXL345_SENSITIVITY_16G 32.0f
+#define ADXL345_SEN_FULL_RES 4.0f
+
+//Gravity at Earth's surface in m/s/s
+#define GRAVITY (9.80665f / 1000)
+
+#if MBED_MAJOR_VERSION == 2
+#define WAIT_MS(x) wait_ms(x)
+#elif MBED_MAJOR_VERSION == 5
+#define WAIT_MS(x) Thread::wait(x)
+#else
+#error "Running on Unknown OS"
+#endif
+
+ADXL345::ADXL345 (PinName p_sda, PinName p_scl,
+ uint8_t addr, uint8_t data_rate, uint8_t fullscale) :
+ _i2c_p(new I2C(p_sda, p_scl)), _i2c(*_i2c_p)
+{
+ _i2c.frequency(400000);
+ initialize (addr, data_rate, fullscale);
+}
+
+ADXL345::ADXL345 (PinName p_sda, PinName p_scl, uint8_t addr) :
+ _i2c_p(new I2C(p_sda, p_scl)), _i2c(*_i2c_p)
+{
+ _i2c.frequency(400000);
+ initialize (addr, ADXL345_DR_200HZ, ADXL345_FULL_RES_16G);
+}
+
+ADXL345::ADXL345 (PinName p_sda, PinName p_scl) :
+ _i2c_p(new I2C(p_sda, p_scl)), _i2c(*_i2c_p)
+{
+ _i2c.frequency(400000);
+ initialize(ADXL345_V_CHIP_ADDR, ADXL345_DR_200HZ, ADXL345_FULL_RES_16G);
+ if (acc_ready == false){
+ initialize(ADXL345_G_CHIP_ADDR, ADXL345_DR_200HZ, ADXL345_FULL_RES_16G);
+ }
+}
+
+ADXL345::ADXL345 (I2C& p_i2c,
+ uint8_t addr, uint8_t data_rate, uint8_t fullscale) : _i2c(p_i2c)
+{
+ _i2c.frequency(400000);
+ initialize (addr, data_rate, fullscale);
+}
+
+ADXL345::ADXL345 (I2C& p_i2c, uint8_t addr) : _i2c(p_i2c)
+{
+ _i2c.frequency(400000);
+ initialize (addr, ADXL345_DR_200HZ, ADXL345_FULL_RES_16G);
+}
+
+ADXL345::ADXL345 (I2C& p_i2c) : _i2c(p_i2c)
+{
+ _i2c.frequency(400000);
+ initialize(ADXL345_V_CHIP_ADDR, ADXL345_DR_200HZ, ADXL345_FULL_RES_16G);
+ if (acc_ready == false){
+ initialize(ADXL345_G_CHIP_ADDR, ADXL345_DR_200HZ, ADXL345_FULL_RES_16G);
+ }
+}
+
+void ADXL345::initialize (uint8_t addr, uint8_t data_rate, uint8_t fullscale)
+{
+ // Check acc is available or not
+ acc_addr = addr;
+ dt[0] = ADXL345_DEVID;
+ _i2c.write(acc_addr, dt, 1, true);
+ _i2c.read(acc_addr, dt, 1, false);
+ if (dt[0] == ADXL345_DEVICE_ID){
+ acc_ready = true;
+ } else {
+ acc_ready = false;
+ return; // acc chip is NOT on I2C line then terminate
+ }
+ // BW Rate
+ dt[0] = ADXL345_BW_RATE;
+ dt[1] = data_rate | ADXL345_NOT_LOW_PWR; // normal(not low power mode)
+ setting_data[0] = dt[1];
+ _i2c.write(acc_addr, dt, 2, false);
+ // Data format (measurement range)
+ dt[0] = ADXL345_DATA_FORMAT;
+ dt[1] = fullscale;
+ setting_data[1] = dt[1];
+ _i2c.write(acc_addr, dt, 2, false);
+ switch (fullscale){
+ case ADXL345_FS_2G:
+ fs_factor = ADXL345_SENSITIVITY_2G;
+ break;
+ case ADXL345_FS_4G:
+ fs_factor = ADXL345_SENSITIVITY_4G;
+ break;
+ case ADXL345_FS_8G:
+ fs_factor = ADXL345_SENSITIVITY_8G;
+ break;
+ case ADXL345_FS_16G:
+ fs_factor = ADXL345_SENSITIVITY_16G;
+ break;
+ case ADXL345_FULL_RES_16G:
+ fs_factor = ADXL345_SEN_FULL_RES;
+ break;
+ default:
+ fs_factor = 1.0f;
+ break;
+ }
+ // Data ready flag
+ dt[0] = ADXL345_INT_ENABLE;
+ dt[1] = 0x80;
+ setting_data[2] = dt[1];
+ _i2c.write(acc_addr, dt, 2, false);
+ // Start measurement mode
+ dt[0] = ADXL345_POWER_CTL;
+ dt[1] = 0x08;
+ setting_data[3] = dt[1];
+ _i2c.write(acc_addr, dt, 2, false);
+ // offset compensation
+ dt[0] = ADXL345_OFSX;
+ dt[1] = 0x01;
+ _i2c.write(acc_addr, dt, 2, false);
+ dt[0] = ADXL345_OFSY;
+ dt[1] = 0x00;
+ _i2c.write(acc_addr, dt, 2, false);
+ dt[0] = ADXL345_OFSZ;
+ dt[1] = 0x00;
+ _i2c.write(acc_addr, dt, 2, false);
+}
+
+void ADXL345::read_reg_data(char *data)
+{
+ // read all of X,Y & Z
+ dt[0] = ADXL345_DATAX0;
+ _i2c.write(acc_addr, dt, 1, true);
+ _i2c.read(acc_addr, data, 6, false);
+}
+
+void ADXL345::read_mg_data(float *dt_usr)
+{
+ return read_mg_g_data(dt_usr, 0);
+}
+
+void ADXL345::read_g_data(float *dt_usr)
+{
+ return read_mg_g_data(dt_usr, 1);
+}
+
+void ADXL345::read_data(float *dt_usr)
+{
+ return read_mg_g_data(dt_usr, 2);
+}
+
+void ADXL345::read_mg_g_data(float *dt_usr, uint8_t n)
+{
+ char data[6];
+ float fct;
+
+ if (acc_ready == false){
+ dt_usr[0] = 0;
+ dt_usr[1] = 0;
+ dt_usr[2] = 0;
+ return;
+ }
+ read_reg_data(data);
+ if (n == 0){
+ fct = fs_factor;
+ } else if (n == 1){
+ fct = fs_factor / 1000.0f;
+ } else {
+ fct = fs_factor * GRAVITY;
+ }
+ // change data type
+ dt_usr[0] = float(int16_t((data[1] << 8) | data[0])) * fct;
+ dt_usr[1] = float(int16_t((data[3] << 8) | data[2])) * fct;
+ dt_usr[2] = float(int16_t((data[5] << 8) | data[4])) * fct;
+}
+
+uint8_t ADXL345::read_id()
+{
+ dt[0] = ADXL345_DEVID;
+ _i2c.write(acc_addr, dt, 1, true);
+ _i2c.read(acc_addr, dt, 1, false);
+ return (uint8_t)dt[0];
+}
+
+bool ADXL345::data_ready()
+{
+ if (acc_ready == true){
+ dt[0] = ADXL345_INT_SOURCE;
+ _i2c.write(acc_addr, dt, 1, true);
+ _i2c.read(acc_addr, dt, 1, false);
+ if (dt[0] & 0x80){ // Check ready bit
+ return true;
+ } else {
+ return false;
+ }
+ }
+ return false;
+}
+
+void ADXL345::frequency(int hz)
+{
+ _i2c.frequency(hz);
+}
+
+uint8_t ADXL345::read_reg(uint8_t addr)
+{
+ if (acc_ready == true){
+ dt[0] = addr;
+ _i2c.write(acc_addr, dt, 1, true);
+ _i2c.read(acc_addr, dt, 1, false);
+ } else {
+ dt[0] = 0xff;
+ }
+ return (uint8_t)dt[0];
+}
+
+void ADXL345::write_reg(uint8_t addr, uint8_t data)
+{
+ if (acc_ready == true){
+ dt[0] = addr;
+ dt[1] = data;
+ _i2c.write(acc_addr, dt, 2, false);
+ }
+}
+
+void ADXL345::debug_print(void)
+{
+ printf("ADXL345 3-axes accelerometer\r\n");
+ printf(" DEVID=0x%02x\r\n", read_reg(ADXL345_DEVID));
+ printf(" THRESH_TAP=0x%02x\r\n", read_reg(ADXL345_THRESH_TAP));
+ printf(" OFSX=0x%02x,", read_reg(ADXL345_OFSX));
+ printf(" OFSY=0x%02x,", read_reg(ADXL345_OFSY));
+ printf(" OFSZ=0x%02x\r\n", read_reg(ADXL345_OFSZ));
+ printf(" DUR=0x%02x,", read_reg(ADXL345_DUR));
+ printf(" LATENT=0x%02x,", read_reg(ADXL345_LATENT));
+ printf(" WINDOW=0x%02x\r\n", read_reg(ADXL345_WINDOW));
+ printf(" THRESH_ACT=0x%02x,", read_reg(ADXL345_THRESH_ACT));
+ printf(" THRESH_INACT=0x%02x\r\n", read_reg(ADXL345_THRESH_INACT));
+ printf(" TIME_INACT=0x%02x,", read_reg(ADXL345_TIME_INACT));
+ printf(" ACT_INACT_CTL=0x%02x\r\n",
+ read_reg(ADXL345_ACT_INACT_CTL));
+ printf(" THRESH_FF=0x%02x,", read_reg(ADXL345_THRESH_FF));
+ printf(" TIME_FF=0x%02x,", read_reg(ADXL345_TIME_FF));
+ printf(" TAP_AXES=0x%02x,", read_reg(ADXL345_TAP_AXES));
+ printf(" ACT_TAP_STATUS=0x%02x\r\n",
+ read_reg(ADXL345_ACT_TAP_STATUS));
+ printf(" BW_RATE=0x%02x\r\n", read_reg(ADXL345_BW_RATE));
+ printf(" POWER_CTL=0x%02x\r\n", read_reg(ADXL345_POWER_CTL));
+ printf(" INT_ENABLE=0x%02x,", read_reg(ADXL345_INT_ENABLE));
+ printf(" INT_MAP=0x%02x,", read_reg(ADXL345_INT_MAP));
+ printf(" INT_SOURCE=0x%02x\r\n", read_reg(ADXL345_INT_SOURCE));
+ printf(" DATA_FORMAT=0x%02x\r\n", read_reg(ADXL345_DATA_FORMAT));
+ printf(" DATAX0=0x%02x,", read_reg(ADXL345_DATAX0));
+ printf(" 1=0x%02x,", read_reg(ADXL345_DATAX1));
+ printf(" DATAY0=0x%02x,", read_reg(ADXL345_DATAY0));
+ printf(" 1=0x%02x,", read_reg(ADXL345_DATAY1));
+ printf(" DATAZ0=0x%02x,", read_reg(ADXL345_DATAZ0));
+ printf(" 1=0x%02x\r\n", read_reg(ADXL345_DATAZ1));
+ printf(" FIFO_CTL=0x%02x,", read_reg(ADXL345_FIFO_CTL));
+ printf(" FIFO_STATUS=0x%02x\r\n", read_reg(ADXL345_FIFO_STATUS));
+ // internal data
+ printf(" ---- fs_factor=%f, acc_addr=0x%02x\r\n", fs_factor, acc_addr);
+}
+
+void ADXL345::self_test(void)
+{
+ float dt0[3] ={0};
+ float dt1[3] ={0};
+ float dt2[3];
+
+ dt[0] = ADXL345_DATA_FORMAT;
+ dt[1] = 0x0B;
+ _i2c.write(acc_addr, dt, 2, false);
+ dt[0] = ADXL345_POWER_CTL;
+ dt[1] = 0x08;
+ _i2c.write(acc_addr, dt, 2, false);
+ dt[0] = ADXL345_INT_ENABLE;
+ dt[1] = 0x80;
+ _i2c.write(acc_addr, dt, 2, false);
+ WAIT_MS(40);
+ for(uint8_t n = 0; n < 100; n++){
+ read_data(dt2);
+ dt0[0] += dt2[0];
+ dt0[1] += dt2[1];
+ dt0[2] += dt2[2];
+ }
+ dt0[0] /= 100;
+ dt0[1] /= 100;
+ dt0[2] /= 100;
+ //
+ dt[0] = ADXL345_DATA_FORMAT;
+ dt[1] = 0x8B;
+ _i2c.write(acc_addr, dt, 2, false);
+ WAIT_MS(40);
+ for(uint8_t n = 0; n < 100; n++){
+ read_data(dt2);
+ dt1[0] += dt2[0];
+ dt1[1] += dt2[1];
+ dt1[2] += dt2[2];
+ }
+ dt1[0] /= 100;
+ dt1[1] /= 100;
+ dt1[2] /= 100;
+ printf("X, 1st, %+8.4f, 2nd, %+8.4f, diff, %+8.4f\r\n",
+ dt0[0], dt1[0], dt0[0] - dt1[0]);
+ printf("Y, 1st, %+8.4f, 2nd, %+8.4f, diff, %+8.4f\r\n",
+ dt0[1], dt1[1], dt0[1] - dt1[1]);
+ printf("Z, 1st, %+8.4f, 2nd, %+8.4f, diff, %+8.4f\r\n",
+ dt0[2], dt1[2], dt0[2] - dt1[2]);
+ //Recover original setting
+ // BW Rate
+ dt[0] = ADXL345_BW_RATE;
+ dt[1] = setting_data[0];
+ _i2c.write(acc_addr, dt, 2, false);
+ // Data format (measurement range)
+ dt[0] = ADXL345_DATA_FORMAT;
+ dt[1] = setting_data[1];
+ _i2c.write(acc_addr, dt, 2, false);
+ // Data ready flag
+ dt[0] = ADXL345_INT_ENABLE;
+ dt[1] = setting_data[2];
+ _i2c.write(acc_addr, dt, 2, false);
+ // Start measurement mode
+ dt[0] = ADXL345_POWER_CTL;
+ dt[1] = setting_data[3];
+ _i2c.write(acc_addr, dt, 2, false);
+ WAIT_MS(40);
+ read_data(dt2); // dummy read
+}