From e8615511d97ae0dfd74dcec36a28f34db776612d Mon Sep 17 00:00:00 2001
From: William Clark <wrvc96@gmail.com>
Date: Wed, 10 Jan 2024 17:57:25 +0000
Subject: [PATCH] interupt reg + sync reads

---
 main.c    | 12 +++---------
 mpu6050.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++--
 mpu6050.h | 12 ++++++++++++
 3 files changed, 68 insertions(+), 11 deletions(-)

diff --git a/main.c b/main.c
index 4ee7373..cd8e675 100644
--- a/main.c
+++ b/main.c
@@ -23,6 +23,7 @@ int main() {
 
     mpu6050.cfg.gyro = MPU6050_GYRO_FS_250;
     mpu6050.cfg.acc = MPU6050_ACC_FS_2G;
+    mpu6050.cfg.int_enable.data_rdy = 1;
 
     /* reset all signal paths */
     /* enable gyro, acc and temp */
@@ -48,7 +49,7 @@ int main() {
 
     /* enable DATA_RDY interrupt (polling for now) */
     /* active when internal writes to all out data regs are done */
-    if (i2c_write(REG_INT_ENABLE, 0x01)) {
+    if (i2c_write(REG_INT_ENABLE, mpu6050.cfg.int_enable.data_rdy & 1)) {
         exit(1);
     }
 
@@ -63,15 +64,8 @@ int main() {
     usleep(200 * 1000);
 
 LOOP:
-    if (mpu6050_read_gyro(&mpu6050)) {
-        exit(1);
-    }
 
-    if (mpu6050_read_acc(&mpu6050)) {
-        exit(1);
-    }
-
-    if (mpu6050_read_temp(&mpu6050)) {
+    if (mpu6050_read(&mpu6050)) {
         exit(1);
     }
 
diff --git a/mpu6050.c b/mpu6050.c
index cca6453..a162ca0 100644
--- a/mpu6050.c
+++ b/mpu6050.c
@@ -44,12 +44,20 @@ int mpu6050_deinit(mpu6050_t *mpu6050) {
 int mpu6050_read_acc(mpu6050_t *mpu6050) {
     uint8_t data[6];
     uint8_t shift;
+    uint8_t int_status;
     int err = 0;
 
     assert(mpu6050);
-
     shift = acc_i16_shift(mpu6050->cfg.acc);
 
+    /* if data_rdy interrupt is enabled, wait for data to be ready */
+    if (mpu6050->cfg.int_enable.data_rdy) {
+        do {
+            err |= mpu6050->dev.read(REG_INT_STATUS, &int_status, 1);
+            mpu6050->dev.sleep(1000); /* 1 ms */
+        } while(!err && !(int_status & 1));
+    }
+
     err |= mpu6050->dev.read(REG_ACCEL_XOUT_H, data, 6);
     mpu6050->data.acc.x = (int16_t)(data[0] << 8 | data[1]) >> shift;
     mpu6050->data.acc.y = (int16_t)(data[2] << 8 | data[3]) >> shift;
@@ -62,12 +70,20 @@ int mpu6050_read_acc(mpu6050_t *mpu6050) {
 int mpu6050_read_gyro(mpu6050_t *mpu6050) {
     uint8_t data[6];
     uint8_t shift;
+    uint8_t int_status;
     int err = 0;
 
     assert(mpu6050);
-
     shift = gyro_i16_shift(mpu6050->cfg.gyro);
 
+    /* if data_rdy interrupt is enabled, wait for data to be ready */
+    if (mpu6050->cfg.int_enable.data_rdy) {
+        do {
+            err |= mpu6050->dev.read(REG_INT_STATUS, &int_status, 1);
+            mpu6050->dev.sleep(1000); /* 1 ms */
+        } while(!err && !(int_status & 1));
+    }
+
     err |= mpu6050->dev.read(REG_GYRO_XOUT_H, data, 6);
 
     mpu6050->data.gyro.x = ((int16_t)(data[0] << 8 | data[1]) >> shift);
@@ -89,6 +105,41 @@ int mpu6050_read_temp(mpu6050_t *mpu6050) {
     return err;
 }
 
+/* combines the operations of read_temp(), read_gyro() and read_acc() */
+/* if data_rdy interrupt is enabled, this will read all data synched */
+int mpu6050_read(mpu6050_t *mpu6050) {
+    uint8_t data[14]; /* gyro + accel + temp */
+    uint8_t shift_gyro, shift_acc, int_status;
+    int err = 0;
+
+    assert(mpu6050);
+
+    shift_gyro = gyro_i16_shift(mpu6050->cfg.gyro);
+    shift_acc = acc_i16_shift(mpu6050->cfg.acc);
+
+    /* if data_rdy interrupt is enabled, wait for data to be ready */
+    if (mpu6050->cfg.int_enable.data_rdy) {
+        do {
+            err |= mpu6050->dev.read(REG_INT_STATUS, &int_status, 1);
+            mpu6050->dev.sleep(1000); /* 1 ms */
+        } while(!err && !(int_status & 1));
+    }
+
+    err |= mpu6050->dev.read(REG_ACCEL_XOUT_H, data, 14);
+    /* 0-5 acc */
+    mpu6050->data.acc.x = (int16_t)(data[0] << 8 | data[1]) >> shift_acc;
+    mpu6050->data.acc.y = (int16_t)(data[2] << 8 | data[3]) >> shift_acc;
+    mpu6050->data.acc.z = (int16_t)(data[4] << 8 | data[5]) >> shift_acc;
+    /* 6-7 temp */
+    mpu6050->data.temp = (int16_t)(data[6] << 8 | data[7])/34 + 365;
+    /* 8-13 gyro */
+    mpu6050->data.gyro.x = ((int16_t)(data[ 8] << 8 | data[ 9]) >> shift_gyro);
+    mpu6050->data.gyro.y = ((int16_t)(data[10] << 8 | data[11]) >> shift_gyro);
+    mpu6050->data.gyro.z = ((int16_t)(data[12] << 8 | data[13]) >> shift_gyro);
+
+    return err;
+}
+
 /* How much to shift down an i16 accel sample depending on full-scale mode set */
 static uint8_t acc_i16_shift(uint8_t fs) {
     switch(fs) {
diff --git a/mpu6050.h b/mpu6050.h
index 92bb124..104d495 100644
--- a/mpu6050.h
+++ b/mpu6050.h
@@ -23,9 +23,19 @@ struct mpu6050_dev {
     int (*deinit)(void);
 };
 
+/* for configuring REG_INT_ENABLE */
+struct mpu6050_int_enable {
+    uint8_t mot; /* enables motion detect interrupt */
+    uint8_t fifo_overflow; /* enables FIFO buffer overflow interrupt */
+    uint8_t i2c_mst; /* enables any i2c master to generate interrupt */
+    uint8_t data_rdy; /* enable interrupt upon finished write to data out registers */
+};
+
+/* configuring variables that are written to the device */
 struct mpu6050_config {
     uint8_t gyro;
     uint8_t acc;
+    struct mpu6050_int_enable int_enable;
 };
 
 /* 1 lsb = 1 mg (1/1000 g) */
@@ -42,6 +52,7 @@ struct mpu6050_gyroscope {
     int16_t z;
 };
 
+/* stores all converted data read from the device */
 struct mpu6050_data {
     struct mpu6050_accelerometer acc;
     struct mpu6050_gyroscope gyro;
@@ -61,5 +72,6 @@ int mpu6050_deinit(mpu6050_t *mpu6050);
 int mpu6050_read_acc(mpu6050_t *mpu6050);
 int mpu6050_read_gyro(mpu6050_t *mpu6050);
 int mpu6050_read_temp(mpu6050_t *mpu6050);
+int mpu6050_read(mpu6050_t *mpu6050);
 
 #endif
\ No newline at end of file