stm32/accel: Add support for KXTJ3.

1 files changed, 69 insertions, 7 deletions

diff --git a/ports/stm32/accel.c b/ports/stm32/accel.c
index b4916b5059..634ed0a752 100644
--- a/ports/stm32/accel.c
+++ b/ports/stm32/accel.c
@@ -33,21 +33,30 @@
 #include "i2c.h"
 #include "accel.h"
 
-#if MICROPY_HW_HAS_MMA7660
+#if MICROPY_HW_HAS_MMA7660 || MICROPY_HW_HAS_KXTJ3
 
 /// \moduleref pyb
 /// \class Accel - accelerometer control
 ///
-/// Accel is an object that controls the accelerometer.  Example usage:
+/// Accel is an object that controls the MMA7660 or the KXTJ3 accelerometer
+/// depending on one/two constant in mpconfigboard.h file of board project :
+/// #define MICROPY_HW_HAS_MMA7660      (1)
+/// #define MICROPY_HW_HAS_KXTJ3        (0) // not mandatory if equal to 0
+///
+/// Example usage:
 ///
 ///     accel = pyb.Accel()
 ///     for i in range(10):
 ///         print(accel.x(), accel.y(), accel.z())
 ///
-/// Raw values are between -32 and 31.
+/// Raw values are between -32 and 31 for -/+ 1.5G acceleration for MMA7660.
+/// Raw values are between -128 and 127 for -/+ 8G acceleration for KXTJ3.
+
 
 #define I2C_TIMEOUT_MS (50)
 
+#if MICROPY_HW_HAS_MMA7660
+
 #define ACCEL_ADDR                  (76)
 #define ACCEL_REG_X                 (0)
 #define ACCEL_REG_Y                 (1)
@@ -56,16 +65,36 @@
 #define ACCEL_REG_MODE              (7)
 #define ACCEL_AXIS_SIGNED_VALUE(i)  (((i) & 0x3f) | ((i) & 0x20 ? (~0x1f) : 0))
 
+#elif MICROPY_HW_HAS_KXTJ3
+
+#define ACCEL_ADDR                  (0x0f)
+#define ACCEL_REG_DCST_RESP         (0x0c)
+#define ACCEL_REG_WHO_AM_I          (0x0f)
+#define ACCEL_REG_X                 (0x07) // XOUT_H
+#define ACCEL_REG_Y                 (0x09) // YOUT_H
+#define ACCEL_REG_Z                 (0x0B) // ZOUT_H
+#define ACCEL_REG_CTRL_REG1         (0x1B)
+#define ACCEL_REG_CTRL_REG2         (0x1d)
+#define ACCEL_REG_CTRL_REG2         (0x1d)
+#define ACCEL_REG_DATA_CTRL_REG     (0x21)
+#define ACCEL_AXIS_SIGNED_VALUE(i)  (((i) & 0x7f) | ((i) & 0x80 ? (~0x7f) : 0))
+
+#endif
+
 void accel_init(void) {
+    #if MICROPY_HW_HAS_MMA7660
     // PB5 is connected to AVDD; pull high to enable MMA accel device
     mp_hal_pin_low(MICROPY_HW_MMA_AVDD_PIN); // turn off AVDD
     mp_hal_pin_output(MICROPY_HW_MMA_AVDD_PIN);
+    #endif
 }
 
 STATIC void accel_start(void) {
     // start the I2C bus in master mode
     i2c_init(I2C1, MICROPY_HW_I2C1_SCL, MICROPY_HW_I2C1_SDA, 400000, I2C_TIMEOUT_MS);
 
+    #if MICROPY_HW_HAS_MMA7660
+
     // turn off AVDD, wait 30ms, turn on AVDD, wait 30ms again
     mp_hal_pin_low(MICROPY_HW_MMA_AVDD_PIN); // turn off
     mp_hal_delay_ms(30);
@@ -90,6 +119,27 @@ STATIC void accel_start(void) {
 
     // wait for MMA to become active
     mp_hal_delay_ms(30);
+
+    #elif MICROPY_HW_HAS_KXTJ3
+
+    // readout WHO_AM_I register to check KXTJ3 device presence
+    uint8_t data[2] = { ACCEL_REG_WHO_AM_I };
+    i2c_writeto(I2C1, ACCEL_ADDR, data, 1, false);
+    i2c_readfrom(I2C1, ACCEL_ADDR, data, 1, true);
+    if (data[0] != 0x35) {
+        mp_raise_msg(&mp_type_OSError, "accelerometer not found");
+    }
+
+    // set operating mode (default: 8 bits, range +/-8G)
+    data[0] = ACCEL_REG_CTRL_REG1;
+    data[1] = 0x90;
+    i2c_writeto(I2C1, ACCEL_ADDR, data, 2, true);
+    // set dat output rates to 200Hz (LPF roll-over 10ms), idd=35uA
+    data[0] = ACCEL_REG_DATA_CTRL_REG;
+    data[1] = 0x04;
+    i2c_writeto(I2C1, ACCEL_ADDR, data, 2, true);
+
+    #endif
 }
 
 /******************************************************************************/
@@ -158,10 +208,15 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_z_obj, pyb_accel_z);
 /// \method tilt()
 /// Get the tilt register.
 STATIC mp_obj_t pyb_accel_tilt(mp_obj_t self_in) {
+    #if MICROPY_HW_HAS_MMA7660
     uint8_t data[1] = { ACCEL_REG_TILT };
     i2c_writeto(I2C1, ACCEL_ADDR, data, 1, false);
     i2c_readfrom(I2C1, ACCEL_ADDR, data, 1, true);
     return mp_obj_new_int(data[0]);
+    #elif MICROPY_HW_HAS_KXTJ3
+    /// No tilt like register with KXTJ3 accelerometer
+    return 0;
+    #endif
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_tilt_obj, pyb_accel_tilt);
 
@@ -172,13 +227,20 @@ STATIC mp_obj_t pyb_accel_filtered_xyz(mp_obj_t self_in) {
 
     memmove(self->buf, self->buf + NUM_AXIS, NUM_AXIS * (FILT_DEPTH - 1) * sizeof(int16_t));
 
-    uint8_t data[NUM_AXIS] = { ACCEL_REG_X };
+    #if MICROPY_HW_HAS_MMA7660
+    const size_t DATA_SIZE = NUM_AXIS;
+    const size_t DATA_STRIDE = 1;
+    #elif MICROPY_HW_HAS_KXTJ3
+    const size_t DATA_SIZE = 5;
+    const size_t DATA_STRIDE = 2;
+    #endif
+    uint8_t data[DATA_SIZE]; data[0] = ACCEL_REG_X;
     i2c_writeto(I2C1, ACCEL_ADDR, data, 1, false);
-    i2c_readfrom(I2C1, ACCEL_ADDR, data, 3, true);
+    i2c_readfrom(I2C1, ACCEL_ADDR, data, DATA_SIZE, true);
 
     mp_obj_t tuple[NUM_AXIS];
     for (int i = 0; i < NUM_AXIS; i++) {
-        self->buf[NUM_AXIS * (FILT_DEPTH - 1) + i] = ACCEL_AXIS_SIGNED_VALUE(data[i]);
+        self->buf[NUM_AXIS * (FILT_DEPTH - 1) + i] = ACCEL_AXIS_SIGNED_VALUE(data[i * DATA_STRIDE]);
         int32_t val = 0;
         for (int j = 0; j < FILT_DEPTH; j++) {
             val += self->buf[i + NUM_AXIS * j];
@@ -225,4 +287,4 @@ const mp_obj_type_t pyb_accel_type = {
     .locals_dict = (mp_obj_dict_t*)&pyb_accel_locals_dict,
 };
 
-#endif // MICROPY_HW_HAS_MMA7660
+#endif // MICROPY_HW_HAS_MMA7660 || MICROPY_HW_HAS_KXTJ3