Diff: main.cpp

Revision:

0:0dc9a3be9863

Child:

1:b4065d4d692a

diff -r 000000000000 -r 0dc9a3be9863 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Sep 19 02:40:41 2016 +0000
@@ -0,0 +1,169 @@
+/**
+ *  @brief simple accelerometer reading demo
+ */
+#include "mbed.h"
+#include "rtos.h"
+#include "ST7567.h"
+
+/* defines the axis for acc */
+#define ACC_NOOF_AXIS       3
+
+/* defines the time of acquisition in ms */
+#define ACC_SAMPLE_RATE     200
+
+/* acc event flags */
+#define ACC_EVENT           0x00000001
+
+/* bmi160 slave address */
+#define BMI160_ADDR         ((0x68)<<1)
+
+/* LCD parameters */
+#define LCD_HEIGHT          64
+#define LCD_WIDTH           128
+#define FONT_HEIGHT         10
+#define FONT_WIDTH          5
+
+/* Debug LED */
+DigitalOut debug_led(LED1);
+
+/* thread for accelerometer and LCD */
+
+unsigned char acc_stack[1024];
+unsigned char lcd_stack[1024];
+Thread acc_thread(osPriorityRealtime, 1024 ,&acc_stack[0]);
+Thread lcd_thread(osPriorityNormal, 1024, &lcd_stack[0]);
+
+/* semaphore to sync acc reading to lcd printing */
+Semaphore acc_sema;
+
+/* buffer to store acc samples */
+int16_t acc_sample_buffer[ACC_NOOF_AXIS] = {0x5555, 0x5555, 0x5555};
+uint8_t acc_status = 0;
+
+
+
+/**
+ * @brief i2c event callback
+ */
+
+/**
+ * @brief accelerometer processing task 
+ */
+static void acc_task(void) {
+    I2C *imu_comm = new I2C(P2_3, P2_4);
+    char i2c_reg_buffer[2] = {0};
+    
+    /* setup the frequency */
+    imu_comm->frequency(20000);
+
+    /* issue a sw reset */
+    i2c_reg_buffer[0] = 0x7E;
+    i2c_reg_buffer[1] = 0xB6;    
+    imu_comm->write(BMI160_ADDR, i2c_reg_buffer, sizeof(i2c_reg_buffer), false);
+
+    /* wait property time for device reset */
+    Thread::wait(200);
+
+    /* enable the accelerometer */
+    i2c_reg_buffer[0] = 0x7E;
+    i2c_reg_buffer[1] = 0x11;    
+    imu_comm->write(BMI160_ADDR, i2c_reg_buffer, sizeof(i2c_reg_buffer), false);
+ 
+    /* sets the output data rate to 100 Hz */
+    i2c_reg_buffer[0] = 0x40;
+    i2c_reg_buffer[1] = 0x28;    
+    imu_comm->write(BMI160_ADDR, i2c_reg_buffer, sizeof(i2c_reg_buffer), false);
+ 
+    for(;;) {
+        int err = 0;
+        
+        /* reads status register */
+        i2c_reg_buffer[0] = 0x02;
+        err = imu_comm->write(BMI160_ADDR, i2c_reg_buffer, 1, true);
+        err = imu_comm->read(BMI160_ADDR, (char *)&acc_status, sizeof(acc_status), false);
+        
+        /* reads the acc register */
+        i2c_reg_buffer[0] = 0x12;
+        err = imu_comm->write(BMI160_ADDR, i2c_reg_buffer, 1, true);
+        err = imu_comm->read(BMI160_ADDR, (char *)&acc_sample_buffer, sizeof(acc_sample_buffer), false);
+
+        acc_sema.release();
+        Thread::wait(200);
+    }    
+}
+
+
+/**
+ * @brief lcd update task 
+ */
+static void lcd_task(void) {
+    const char banner[] = {"Embarcados IMU demo\0"};
+    const char x_axis_text[] = {"x raw axis:\0"};
+    const char y_axis_text[] = {"y raw axis:\0"};
+    const char z_axis_text[] = {"z raw axis:\0"};
+    const char status_text[] = {"acc status:\0"};
+    DigitalOut *lcd_led = new DigitalOut(LED3);
+    
+    char acc_buffer[8] = {0}; 
+    
+    *lcd_led = 1;
+    
+    /* creates an spi lcd object */
+    ST7567 *lcd = new ST7567(D11, D13, D12, D9, D10);
+    lcd->set_contrast(0x35); 
+    lcd->cls();  
+    
+    /* center the text banner */
+    lcd->locate((LCD_WIDTH - (sizeof(banner) * FONT_WIDTH))/2,1); 
+    lcd->printf(banner);
+    
+    lcd->locate(0, FONT_HEIGHT * 2);
+    lcd->printf(x_axis_text);
+    lcd->locate(0, FONT_HEIGHT * 3);
+    lcd->printf(y_axis_text);
+    lcd->locate(0, FONT_HEIGHT * 4);
+    lcd->printf(z_axis_text);    
+    lcd->locate(0, FONT_HEIGHT * 5);
+    lcd->printf(status_text);
+
+
+    for(;;) {
+        /* wait for accelerometer event */
+        acc_sema.wait();
+        
+        *lcd_led = 0;
+        
+        /* new samples arrived, format and prints on lcd */
+        sprintf(&acc_buffer[0],"%d", acc_sample_buffer[0]);
+        lcd->locate(sizeof(x_axis_text)*FONT_WIDTH, FONT_HEIGHT * 2);
+        lcd->printf(acc_buffer);
+        
+        sprintf(&acc_buffer[0],"%d", acc_sample_buffer[1]);
+        lcd->locate(sizeof(y_axis_text)*FONT_WIDTH, FONT_HEIGHT * 3);
+        lcd->printf(acc_buffer);
+
+        sprintf(&acc_buffer[0],"%d", acc_sample_buffer[2]);
+        lcd->locate(sizeof(z_axis_text)*FONT_WIDTH, FONT_HEIGHT * 4);
+        lcd->printf(acc_buffer);
+        
+        sprintf(&acc_buffer[0],"%x", acc_status);
+        lcd->locate(sizeof(status_text)*FONT_WIDTH, FONT_HEIGHT * 5);
+        lcd->printf(acc_buffer);
+        
+        *lcd_led = 1;
+        /* block this task until the next semaphore trigger */
+    }
+}
+
+/**
+ * @brief main application entry point
+ */
+int main(void) {
+    
+    debug_led = 1;
+    
+    /* starts the two threads of this app */
+    acc_thread.start(acc_task);
+    lcd_thread.start(lcd_task);
+    debug_led = 0;
+}