scale test, C++ enum and bus_addr

add scale_test executable demonstrating C++lib and scaling, create enum MPU6050::Scale, C++ set bus_addr, remove #include stdlib.h from headers

Author: NirajPatelRobots

i2c/mpu6050_i2c/CMakeLists.txt

@@ -19,3 +19,13 @@ pico_enable_stdio_uart(mpu6050_i2c 0)
 
 # add url via pico_set_program_url
 example_auto_set_url(mpu6050_i2c)
+
+
+add_executable(mpu6050_i2c_scale_test mpu6050_scale_test.cpp)
+target_link_libraries(mpu6050_i2c_scale_test MPU6050_i2c_pico_cpp_lib)
+
+# create map/bin/hex file etc.
+pico_add_extra_outputs(mpu6050_i2c_scale_test)
+# enable usb output, disable uart output
+pico_enable_stdio_usb(mpu6050_i2c_scale_test 1)
+pico_enable_stdio_uart(mpu6050_i2c_scale_test 0)

i2c/mpu6050_i2c/mpu6050.cpp

@@ -1,6 +1,4 @@
 #include "mpu6050.hpp"
-#include "pico/binary_info.h"
-#include "hardware/i2c.h"
 #include "mpu6050_i2c.h"
 
 /*MPU6050::MPU6050() :  //TODO: smart pointers
@@ -11,32 +9,33 @@ chip_temp(*temp) {
     MPU6050(accel, gyro, temp);
 } */
 
-MPU6050::MPU6050(float *accel_out, float *gyro_out) :
- accel(accel_out),  gyro(gyro_out), chip_temp(temp) {
-    accel_scale = 0;
-    gyro_scale = 0;
+MPU6050::MPU6050(float *accel_out, float *gyro_out, uint8_t addr) :
+ chip_temp(temp), accel(accel_out),  gyro(gyro_out), accel_scale(Scale_0), gyro_scale(Scale_0), bus_addr(addr) {
     setup_MPU6050_i2c();
 }
 
 void MPU6050::power(uint8_t CLKSEL, bool temp_disable, bool sleep, bool cycle) {
+    mpu6050_setbusaddr(bus_addr);
     mpu6050_power(CLKSEL, temp_disable, sleep, cycle);
 }
 
 void MPU6050::reset(void) {
+    mpu6050_setbusaddr(bus_addr);
     mpu6050_reset();
 }
 
-void MPU6050::setscale_accel(uint8_t scale_num) {
-    accel_scale = scale_num & 3;
-    mpu6050_setscale_accel((MPU6050_Scale)accel_scale);
+void MPU6050::setscale_accel(MPU6050::Scale scale) {
+    mpu6050_setbusaddr(bus_addr);
+    mpu6050_setscale_accel((MPU6050_Scale)scale);
 }
 
-void MPU6050::setscale_gyro(uint8_t scale_num) {
-    gyro_scale = scale_num & 3;
-    mpu6050_setscale_gyro((MPU6050_Scale)gyro_scale);
+void MPU6050::setscale_gyro(MPU6050::Scale scale) {
+    mpu6050_setbusaddr(bus_addr);
+    mpu6050_setscale_gyro((MPU6050_Scale)scale);
 }
 
 void MPU6050::read(void) {
+    mpu6050_setbusaddr(bus_addr);
     mpu6050_read(accel, gyro, &temp, (MPU6050_Scale)accel_scale, (MPU6050_Scale)gyro_scale);
 }
 

i2c/mpu6050_i2c/mpu6050.hpp

@@ -2,24 +2,28 @@
 An abstraction of pico example C code. 
 TODO:
     smart ptrs for results
-    C++ scale enums
-    mpu6050_t struct in C code for storing scales and bus addr
+    set timing
+    set and read filter cutoff
+    interrupts
  */
-#include "pico/stdlib.h"
+#include "stdint.h"
 
 class MPU6050 {
-    float *accel, *gyro, temp;
-    uint8_t accel_scale, gyro_scale;
 public:
     const float &chip_temp; // [C]
 
     MPU6050(); //TODO
-    MPU6050(float *accel_out, float *gyro_out); // [m/s^2], [rad/s]
+    MPU6050(float *accel_out, float *gyro_out, uint8_t i2c_addr=0x68); // [m/s^2], [rad/s]
 
     void power(uint8_t CLKSEL, bool temp_disable, bool sleep, bool cycle);
     void reset(void);
 
-    void setscale_accel(uint8_t scale_num); //scale 0-3 is 2g, 4g, 8g, or 16g
-    void setscale_gyro(uint8_t scale_num); // scale 0-3 is 250, 500, 1000, or 2000 deg/s
+    enum Scale {Scale_0 = 0, Scale_1, Scale_2, Scale_3};
+    void setscale_accel(Scale scale); //scale 0-3 is 2g, 4g, 8g, or 16g
+    void setscale_gyro(Scale scale); // scale 0-3 is 250, 500, 1000, or 2000 deg/s
     void read(void);
+private:
+    float *accel, *gyro, temp;
+    enum Scale accel_scale, gyro_scale;
+    uint8_t bus_addr;
 };

i2c/mpu6050_i2c/mpu6050_i2c.h

@@ -5,7 +5,8 @@ Niraj Patel March 2022 */
 extern "C" {
 #endif
 
-#include "pico/stdlib.h"
+#include "stdint.h"
+#include "stddef.h"
 
 typedef enum MPU6050_Scale {MPU_FS_0, MPU_FS_1, MPU_FS_2, MPU_FS_3} MPU6050_Scale;
 

i2c/mpu6050_i2c/mpu6050_scale_test.cpp

@@ -0,0 +1,32 @@
+/**
+ * mpu6050 I2c C++ example demonstrating the mpu6050's scaling feature
+ */
+
+#include <stdio.h>
+#include "mpu6050.hpp"
+#include "pico/stdlib.h"
+
+int main() {
+    float accel[3], gyro[3]; // TODO we shouldn't need this
+    MPU6050 *IMU = new MPU6050(accel, gyro);
+    printf("MPU6050 Scaling test\n");
+    IMU->reset();
+    IMU->power(1, false, false, false);
+    printf("Scaled Accelerometer and Gyroscope readings\n");
+    printf("Should be roughly equal before and after scale changes\n");
+    int accel_scale = 0, gyro_scale = 2;
+    while (true) {
+        IMU->setscale_accel((MPU6050::Scale)(accel_scale));
+        IMU->setscale_gyro((MPU6050::Scale)(gyro_scale));
+        printf("\nAcclerometer scale: %i, Gyroscope scale: %i\n", accel_scale, gyro_scale);
+        for (int i = 0; i < 100; i++) {
+            IMU->read();
+            printf("%+6f %+6f %+6f | %+6f %+6f %+6f\r",
+                   accel[0], accel[1], accel[2], gyro[0], gyro[1], gyro[2]);
+            if (i == 0) { printf("\n"); }
+            sleep_ms(10);
+        }
+        accel_scale = (accel_scale + 1) % 4;
+        gyro_scale = (gyro_scale + 1) % 4;
+    }
+}