add irq, C++ timing

Author: NirajPatelRobots

i2c/mpu6050_i2c/mpu6050.cpp

@@ -1,6 +1,26 @@
 #include "mpu6050.hpp"
 #include "mpu6050_i2c.h"
 
+
+MPU6050SensorTimingParams::MPU6050SensorTimingParams(int _bandwidth, float _delay, float _sample_rate)
+    : bandwidth(_bandwidth), delay(_delay), sample_rate(_sample_rate) {}
+
+inline const MPU6050SensorTimingParams convert(mpu6050_timing_params_t *c_struct) {  // unfortunate awkwardness of wrapping a C lib
+    return MPU6050SensorTimingParams(c_struct->bandwidth, c_struct->delay, c_struct->sample_rate);
+}
+
+MPU6050TimingParams::MPU6050TimingParams(uint8_t lowpass_filter_cfg, uint8_t sample_rate_div) {
+    mpu6050_timing_params_t accel_timing_c, gyro_timing_c;
+    mpu6050_calc_timing(lowpass_filter_cfg, sample_rate_div, &accel_timing_c, &gyro_timing_c);
+    accel_timing = convert(&accel_timing_c);
+    gyro_timing = convert(&gyro_timing_c);
+}
+
+MPU6050TimingParams::MPU6050TimingParams(const MPU6050SensorTimingParams &_accel_timing,
+                                         const MPU6050SensorTimingParams &_gyro_timing)
+    : accel_timing(_accel_timing), gyro_timing(_gyro_timing) {}
+
+
 /*MPU6050::MPU6050() :  //TODO: smart pointers
 chip_temp(*temp) {
     accel = {0., 0., 0.};
@@ -45,4 +65,16 @@ bool MPU6050::is_connected() {
     mpu6050_setbusaddr(bus_addr);
     return mpu6050_is_connected();
 }
+
+void MPU6050::set_timing(uint8_t lowpass_filter_cfg, uint8_t sample_rate_div) {
+    mpu6050_setbusaddr(bus_addr);
+    mpu6050_set_timing(lowpass_filter_cfg, sample_rate_div);
+}
+
+MPU6050TimingParams MPU6050::read_timing(void) {
+    mpu6050_timing_params_t accel_timing_c, gyro_timing_c;
+    mpu6050_read_timing(&accel_timing_c, &gyro_timing_c);
+    return MPU6050TimingParams(convert(&accel_timing_c), convert(&gyro_timing_c));
+}
+
 

i2c/mpu6050_i2c/mpu6050.hpp

@@ -2,12 +2,22 @@
 An abstraction of pico example C code. 
 TODO:
     smart ptrs for results
-    set timing
-    set and read filter cutoff
-    interrupts
  */
 #include "stdint.h"
 
+struct MPU6050SensorTimingParams {
+    MPU6050SensorTimingParams() = default;
+    MPU6050SensorTimingParams(int _bandwidth, float _delay, float _sample_rate);
+    int bandwidth; // lowpass filter bandwidth [Hz]
+    float delay; // lowpass filter delay [ms]
+    float sample_rate; // rate of new data loading in the register [Hz]
+};
+struct MPU6050TimingParams {
+    MPU6050TimingParams(uint8_t lowpass_filter_cfg, uint8_t sample_rate_div);
+    MPU6050TimingParams(const MPU6050SensorTimingParams &_accel_timing, const MPU6050SensorTimingParams &_gyro_timing);
+    MPU6050SensorTimingParams accel_timing, gyro_timing;
+};
+
 class MPU6050 {
 public:
     const float &chip_temp; // [C]
@@ -24,6 +34,8 @@ class MPU6050 {
     void setscale_gyro(Scale scale); // scale 0-3 is 250, 500, 1000, or 2000 deg/s
     void read(void);
     bool is_connected(void);
+    void set_timing(uint8_t lowpass_filter_cfg, uint8_t sample_rate_div);
+    MPU6050TimingParams read_timing(void);
 private:
     float *accel, *gyro, temp;
     enum Scale accel_scale, gyro_scale;

i2c/mpu6050_i2c/mpu6050_i2c.c

@@ -34,6 +34,7 @@
 static uint8_t bus_addr = 0x68;
 // Register addresses in the MPU6050 to read and write data to
 const uint8_t REG_ACCEL_OUT = 0x3B, REG_GYRO_OUT = 0x43, REG_TEMP_OUT = 0x41,
+              REG_INT_PIN_CFG = 0x37, REG_INT_ENABLE = 0x38, REG_INT_STATUS = 0x3A,
               REG_SMPRT_DIV = 0x19, REG_SIGNAL_PATH_RESET = 0x68, REG_PWR_MGMT_1 = 0x6B, REG_WHO_AM_I = 0x75,
               REG_CONFIG = 0x1A, REG_GYRO_CONFIG = 0x1B, REG_ACCEL_CONFIG = 0x1C;
 
@@ -172,6 +173,17 @@ void mpu6050_calc_timing(uint8_t filter_cfg, uint8_t sample_rate_div,
     }
 }
 
+void mpu6050_configure_interrupt(bool active_low, bool open_drain, bool latch_pin, bool read_clear, bool enable) {
+    mpu6050_writereg(REG_INT_PIN_CFG,   ((uint8_t)active_low << 7) + ((uint8_t)open_drain << 6)
+                                       + ((uint8_t)latch_pin << 5) + ((uint8_t)read_clear << 4));
+    mpu6050_writereg(REG_INT_ENABLE, (uint8_t)enable);
+}
+uint8_t mpu6050_read_interrupt_status() {
+    uint8_t interrupt_status;
+    mpu6050_readreg(REG_INT_STATUS, &interrupt_status, 1);
+    return interrupt_status;
+}
+
 bool mpu6050_is_connected(void) {
     uint8_t who_are_you = 0;
     mpu6050_readreg(REG_WHO_AM_I, &who_are_you, 1);

i2c/mpu6050_i2c/mpu6050_i2c.h

@@ -37,12 +37,20 @@ bool mpu6050_is_connected();
 void mpu6050_accel_selftest_on();  // TODO: find out what "self test" does
 // turn on the mpu6050's gyroscope self test. Turn it off after a few 100ms with mpu6050_setscale_gyro
 void mpu6050_gyro_selftest_on();
+
 // configure lowpass filter and sample rate. Higher filter_cfg -> slower change, higher sample_rate_div -> slower sampling
 void mpu6050_set_timing(uint8_t lowpass_filter_cfg, uint8_t sample_rate_div);
 void mpu6050_read_timing(mpu6050_timing_params_t *accel_timing, mpu6050_timing_params_t *gyro_timing);
 void mpu6050_calc_timing(uint8_t filter_cfg, uint8_t sample_rate_div,
                          mpu6050_timing_params_t *accel_timing, mpu6050_timing_params_t *gyro_timing);
 
+void mpu6050_configure_interrupt(bool active_low, // Whether the INT pin is active low or active high
+                                 bool open_drain, // Whether the INT pin is push-pull or open-drain
+                                 bool latch_pin,  // Whether the INT pin latches or pulses for 50us
+                                 bool read_clear, // Whether interrupt status bits are cleared by reading interrupt status (default) or on any read
+                                 bool enable);    // Turn interrupts on or off
+uint8_t mpu6050_read_interrupt_status(); // 0 =  no interrupts set, 1 = data ready
+
 //set and use scaling. The first read() after setscale() might not have the updated scaling.
 void mpu6050_setscale_accel(MPU6050_Scale accel_scale);
 void mpu6050_setscale_gyro(MPU6050_Scale gyro_scale);