Added MSA301 driver, library, and example

drivers/msa301/msa301.cpp

@@ -7,24 +7,22 @@
 
 namespace pimoroni {
 
-  enum reg {
-    RESET     = 0x00,
-    X_AXIS    = 0x02,
-    Y_AXIS    = 0x04,
-    Z_AXIS    = 0x06
-    // todo: lots of other features
-  };
-
   void MSA301::init() {
     i2c_init(i2c, 400000);
 
     gpio_set_function(sda, GPIO_FUNC_I2C); gpio_pull_up(sda);
     gpio_set_function(scl, GPIO_FUNC_I2C); gpio_pull_up(scl);
+    
+    if(interrupt != PIN_UNUSED) {
+      gpio_set_function(interrupt, GPIO_FUNC_SIO);
+      gpio_set_dir(interrupt, GPIO_IN);
+      gpio_pull_up(interrupt);
+    }
 
     reset();
 
-    i2c_reg_write_uint8(0x11, 0x00); // set power mode
+    set_power_mode(PowerMode::NORMAL);
-    i2c_reg_write_uint8(0x0f, 0x00); // set range & resolution
+    set_range_and_resolution(Range::G_2, Resolution::BITS_14);
   }
 
   void MSA301::i2c_reg_write_uint8(uint8_t reg, uint8_t value) {
@@ -32,6 +30,13 @@ namespace pimoroni {
     i2c_write_blocking(i2c, address, buffer, 2, false);
   }
 
+  uint8_t MSA301::i2c_reg_read_uint8(uint8_t reg) {
+    uint8_t value;
+    i2c_write_blocking(i2c, address, &reg, 1, true);
+    i2c_read_blocking(i2c, address, (uint8_t *)&value, 1, false);
+    return value;
+  }
+
   int16_t MSA301::i2c_reg_read_int16(uint8_t reg) {
     int16_t value;
     i2c_write_blocking(i2c, address, &reg, 1, true);
@@ -40,15 +45,19 @@ namespace pimoroni {
   }
 
   void MSA301::reset() {
-    i2c_reg_write_uint8(reg::RESET, 0b00100100);
+    i2c_reg_write_uint8(SOFT_RESET, 0b00100100);
     sleep_ms(1);
   }
 
-  float MSA301::get_axis(uint8_t axis, uint8_t sample_count) {
+  uint8_t MSA301::part_id() {
+    return i2c_reg_read_uint8(PART_ID);
+  }
+
+  float MSA301::get_axis(Axis axis, uint8_t sample_count) {
     if(sample_count > 1) {
       int32_t total = 0;
       for(uint8_t i = 0; i < sample_count; i++) {
-        total += i2c_reg_read_int16(axis);
+        total += i2c_reg_read_int16(int(axis));
       }
       total /= sample_count;
       return total / 16384.0f;
@@ -57,4 +66,49 @@ namespace pimoroni {
     return i2c_reg_read_int16(axis) / 16384.0f;
   }
 
+  MSA301::Orientation MSA301::get_orientation() {
+    return (Orientation)((i2c_reg_read_uint8(ORIENTATION_STATUS) >> 4) & 0b11);
+  }
+
+  void MSA301::set_power_mode(MSA301::PowerMode power_mode) {
+    i2c_reg_write_uint8(POWER_MODE_BANDWIDTH, power_mode); 
+  }
+
+  void MSA301::set_range_and_resolution(Range range, MSA301::Resolution resolution) { 
+    i2c_reg_write_uint8(RESOLUTION_RANGE, range | resolution); 
+  }
+
+  void MSA301::set_axis_polarity(int polarity) {
+    i2c_reg_write_uint8(SET_AXIS_POLARITY, polarity);
+  }
+
+  void MSA301::disable_all_interrupts() {
+    enable_interrupts(MSA301::Interrupt::NONE);
+  }
+  
+  void MSA301::enable_interrupts(int interrupts) { 
+    i2c_reg_write_uint8(INTERRUPT_ENABLE_0, interrupts & 0xff); 
+    i2c_reg_write_uint8(INTERRUPT_ENABLE_1, (interrupts & 0xff00) >> 8); 
+  }
+
+  bool MSA301::read_interrupt(Interrupt interrupt) {    
+    if(interrupt == NEW_DATA) {
+      return i2c_reg_read_uint8(DATA_INTERRUPT) & 0b1;  
+    }
+
+    // determine which bit indicates the status of this interrupt
+    uint8_t bit = 0;
+    if(interrupt == FREEFALL)     bit = 0;
+    if(interrupt == ACTIVE)       bit = 2;
+    if(interrupt == DOUBLE_TAP)   bit = 4;
+    if(interrupt == SINGLE_TAP)   bit = 5;
+    if(interrupt == ORIENTATION)  bit = 6;
+    
+    return i2c_reg_read_uint8(MOTION_INTERRUPT) & (1U << bit);
+  }
+
+  void MSA301::set_interrupt_latch(MSA301::InterruptLatchPeriod latch_period, bool reset_latched = false) {
+    i2c_reg_write_uint8(INTERRUPT_LATCH_PERIOD, latch_period | (reset_latched ? 0b10000000: 0b0)); 
+  }
+
 }

drivers/msa301/msa301.hpp

@@ -6,13 +6,37 @@
 namespace pimoroni {
 
   class MSA301 {
+    //--------------------------------------------------
+    // Constants
+    //--------------------------------------------------
+  public:
+    static const uint8_t DEFAULT_I2C_ADDRESS    = 0x26;
+    static const uint8_t DEFAULT_SDA_PIN        = 20;
+    static const uint8_t DEFAULT_SCL_PIN        = 21;
+    static const uint8_t DEFAULT_INT_PIN        = 22;
+    static const uint8_t PIN_UNUSED             = UINT8_MAX;
+    
+    static const uint8_t SOFT_RESET             = 0x00;
+    static const uint8_t PART_ID                = 0x01;
+    static const uint8_t MOTION_INTERRUPT       = 0x09;
+    static const uint8_t DATA_INTERRUPT         = 0x0a;
+    static const uint8_t ORIENTATION_STATUS     = 0x0c;
+    static const uint8_t RESOLUTION_RANGE       = 0x0f;
+    static const uint8_t POWER_MODE_BANDWIDTH   = 0x11;    
+    static const uint8_t SET_AXIS_POLARITY      = 0x12;
+    static const uint8_t INTERRUPT_ENABLE_0     = 0x16;
+    static const uint8_t INTERRUPT_ENABLE_1     = 0x17;
+    static const uint8_t INTERRUPT_LATCH_PERIOD = 0x21;
+    static const uint8_t FREEFALL_DURATION      = 0x22;
+
+  private:
     i2c_inst_t *i2c = i2c0;
 
     // interface pins with our standard defaults where appropriate
-    int8_t address   = 0x26;
+    int8_t address    = DEFAULT_I2C_ADDRESS;
-    int8_t sda       = 20;
+    int8_t sda        = DEFAULT_SDA_PIN;
-    int8_t scl       = 21;
+    int8_t scl        = DEFAULT_SCL_PIN;
-    int8_t interrupt = 22;
+    int8_t interrupt  = DEFAULT_INT_PIN;
 
   public:
     MSA301() {}
@@ -24,13 +48,90 @@ namespace pimoroni {
     void reset();
 
     void i2c_reg_write_uint8(uint8_t reg, uint8_t value);
+    uint8_t i2c_reg_read_uint8(uint8_t reg);
     int16_t i2c_reg_read_int16(uint8_t reg);
 
-    float get_axis(uint8_t axis, uint8_t sample_count = 1);
+    enum Axis {
+      X = 0x02,
+      Y = 0x04,
+      Z = 0x06
+    };
+
+    enum Orientation {
+      PORTRAIT            = 0b00, 
+      PORTRAIT_INVERTED   = 0b01, 
+      LANDSCAPE           = 0b10, 
+      LANDSCAPE_INVERTED  = 0b11
+    };
+
+    enum PowerMode {
+      NORMAL  = 0b00, 
+      LOW     = 0b01, 
+      SUSPEND = 0b10
+    };
+
+    enum Range {
+      G_2   = 0b00, 
+      G_4   = 0b01, 
+      G_8   = 0b10, 
+      G_16  = 0b11
+    };
+
+    enum Resolution {
+      BITS_14   = 0b0000, 
+      BITS_12   = 0b0100, 
+      BITS_10   = 0b1000, 
+      BITS_8    = 0b1100
+    };
+    
+    enum AxisPolarity {
+      INVERT_X  = 0b1000, 
+      INVERT_Y  = 0b0100, 
+      INVERT_Z  = 0b0010, 
+      XY_SWAP   = 0b0001
+    };
+
+    enum Interrupt {
+      NONE          = 0,       
+      ACTIVE        = 0b0000111,
+      NEW_DATA      = 0b1000000000000, 
+      FREEFALL      = 0b0100000000000,
+      ORIENTATION   = 0b1000000, 
+      SINGLE_TAP    = 0b0100000,
+      DOUBLE_TAP    = 0b0010000,
+      Z_ACTIVE      = 0b0000100, 
+      Y_ACTIVE      = 0b0000010, 
+      X_ACTIVE      = 0b0000001
+    };
+
+    enum InterruptLatchPeriod {
+      LATCH_1MS     = 0b1001,      
+      LATCH_2MS     = 0b1011,
+      LATCH_25MS    = 0b1100,
+      LATCH_50MS    = 0b1101,
+      LATCH_100MS   = 0b1110,
+      LATCH_250MS   = 0b0001,
+      LATCH_500MS   = 0b0010,
+      LATCH_1S      = 0b0011,
+      LATCH_2S      = 0b0100,
+      LATCH_4S      = 0b0101,
+      LATCH_8S      = 0b0110
+    };
+
+    uint8_t part_id();
+    float get_axis(Axis axis, uint8_t sample_count = 1);
+    float get_x_axis(uint8_t sample_count = 1) { return this->get_axis(MSA301::X, sample_count); }
+    float get_y_axis(uint8_t sample_count = 1) { return this->get_axis(MSA301::Y, sample_count); }
+    float get_z_axis(uint8_t sample_count = 1) { return this->get_axis(MSA301::Z, sample_count); }
+    Orientation get_orientation();
+    void set_power_mode(MSA301::PowerMode power_mode);
+    void set_range_and_resolution(Range range, MSA301::Resolution resolution);
+    void set_axis_polarity(int polarity);
+    void disable_all_interrupts();
+    void enable_interrupts(int interrupts);
+    void set_interrupt_latch(InterruptLatchPeriod latch_period, bool reset_latched);
+    bool read_interrupt(Interrupt interrupt);    
 
-    const uint8_t X = 0x02;
-    const uint8_t Y = 0x04;
-    const uint8_t Z = 0x06;
   };
-
 }
+

examples/CMakeLists.txt

@@ -7,6 +7,7 @@ add_subdirectory(breakout_matrix11x7)
 add_subdirectory(breakout_trackball)
 add_subdirectory(breakout_sgp30)
 add_subdirectory(breakout_colourlcd240x240)
+add_subdirectory(breakout_msa301)
 
 add_subdirectory(pico_display)
 add_subdirectory(pico_unicorn)

examples/breakout_msa301/CMakeLists.txt

@@ -0,0 +1,16 @@
+set(OUTPUT_NAME msa301_demo)
+
+add_executable(
+  ${OUTPUT_NAME}
+  demo.cpp
+)
+
+# enable usb output, disable uart output
+pico_enable_stdio_usb(${OUTPUT_NAME} 1)
+pico_enable_stdio_uart(${OUTPUT_NAME} 0)
+
+# Pull in pico libraries that we need
+target_link_libraries(${OUTPUT_NAME} pico_stdlib breakout_msa301)
+
+# create map/bin/hex file etc.
+pico_add_extra_outputs(${OUTPUT_NAME})

examples/breakout_msa301/demo.cpp

@@ -0,0 +1,27 @@
+#include <stdio.h>
+#include "pico/stdlib.h"
+
+#include "breakout_msa301.hpp"
+
+using namespace pimoroni;
+
+BreakoutMSA301 msa301;
+
+int main() {
+  stdio_init_all();
+
+  msa301.init();
+
+  uint8_t part_id = msa301.part_id();
+  printf("Found MSA301. Part ID: 0x%02x\n", part_id);
+
+  msa301.enable_interrupts(MSA301::FREEFALL | MSA301::ORIENTATION);
+
+  while(true){
+    printf("%d\n", msa301.read_interrupt(MSA301::FREEFALL));
+    printf("X: %f, Y: %f, Z: %f\n", msa301.get_x_axis(), msa301.get_y_axis(), msa301.get_z_axis());
+    printf("%d\n", msa301.get_orientation());
+    sleep_ms(100);
+  };
+  return 0;
+}

libraries/CMakeLists.txt

@@ -8,6 +8,7 @@ add_subdirectory(breakout_matrix11x7)
 add_subdirectory(breakout_trackball)
 add_subdirectory(breakout_sgp30)
 add_subdirectory(breakout_as7262)
+add_subdirectory(breakout_msa301)
 add_subdirectory(pico_graphics)
 add_subdirectory(pico_display)
 add_subdirectory(pico_unicorn)

libraries/breakout_msa301/CMakeLists.txt

@@ -0,0 +1 @@
+include(breakout_msa301.cmake)

libraries/breakout_msa301/breakout_msa301.cmake

@@ -0,0 +1,11 @@
+set(LIB_NAME breakout_msa301)
+add_library(${LIB_NAME} INTERFACE)
+
+target_sources(${LIB_NAME} INTERFACE
+  ${CMAKE_CURRENT_LIST_DIR}/${LIB_NAME}.cpp
+)
+
+target_include_directories(${LIB_NAME} INTERFACE ${CMAKE_CURRENT_LIST_DIR})
+
+# Pull in pico libraries that we need
+target_link_libraries(${LIB_NAME} INTERFACE pico_stdlib msa301)

libraries/breakout_msa301/breakout_msa301.cpp

@@ -0,0 +1,5 @@
+#include "breakout_msa301.hpp"
+
+namespace pimoroni {
+
+}

libraries/breakout_msa301/breakout_msa301.hpp

@@ -0,0 +1,8 @@
+#pragma once
+
+#include "../../drivers/msa301/msa301.hpp"
+
+namespace pimoroni {
+
+  typedef MSA301 BreakoutMSA301;
+}