add demo for LIS3DSH accelerometer with leds

STM32/libraries/BoardExamples/examples/Discovery407VG/LIS3DSH_demo/LIS3DSH_demo.ino

@@ -0,0 +1,148 @@
+/*
+ * Simple demo to test LIS3DSH found in STM32F4 Discovery board
+ * CS pin = PE3
+ * Use Arduino IDE serial plotter to visualize
+ * 
+ * leds are used to visualize sensor position
+ */
+
+#include "Arduino.h"
+#include <SPI.h>
+
+#define RD 0x80
+#define WR 0x00
+
+#define CTRL_REG4 0x20
+#define CTRL_REG5 0x24
+#define CTRL_REG3 0x23
+
+#define OUT_X_L 0x28
+#define OUT_X_H 0x29
+#define OUT_Y_L 0x2A
+#define OUT_Y_H 0x2B
+#define OUT_Z_L 0x2C
+#define OUT_Z_H 0x2D
+
+#define WHO_AM_I 0x0F
+
+void readReg(uint8_t addr, uint8_t* data) {
+  digitalWrite(PE3, LOW);
+  uint8_t ret =SPI.transfer(addr|RD);   
+  delayMicroseconds(50);
+  ret =SPI.transfer(0x00);   
+  delayMicroseconds(50);
+  //Serial.print("R:");
+  //Serial.println(ret,HEX); 
+  digitalWrite(PE3, HIGH); 
+  *data=ret;
+}
+
+void printXYZ() {
+ 
+  uint8_t xl;
+  readReg(OUT_X_L, &xl); 
+ 
+  uint8_t xh;
+  readReg(OUT_X_H, &xh); 
+ 
+  int16_t X = (xh << 8) | (xl); 
+  
+    if (X<0) {
+    analogWrite(PD12,X*-1/64);
+    analogWrite(PD14,0);
+  } else {    
+    analogWrite(PD14,X/64);
+    analogWrite(PD12,0);
+  }
+
+  uint8_t yl;
+  readReg(OUT_Y_L, &yl); 
+ 
+  uint8_t yh;
+  readReg(OUT_Y_H, &yh); 
+ 
+  int16_t Y = (yh << 8) | (yl); 
+
+  if (Y<0) {
+    analogWrite(PD15,Y*-1/64);
+    analogWrite(PD13,0);
+  } else {    
+    analogWrite(PD13,Y/64);
+    analogWrite(PD15,0);
+  }
+
+  uint8_t zl;
+  readReg(OUT_Z_L, &zl); 
+ 
+  uint8_t zh;
+  readReg(OUT_Z_H, &zh); 
+ 
+  int16_t Z = (zh << 8) | (zl); 
+  
+  
+  Serial.print(X);
+  Serial.print(",");
+  Serial.print(Y);
+  Serial.print(",");
+  Serial.println(Z);
+ 
+}
+
+void initSensor() {
+
+ /* 
+ 
+ taken from datasheet, init with two commands:
+  
+  1. Write CTRL_REG4 = 67h
+  X, Y, Z enabled, ODR = 100 Hz
+  
+  2. Write CTRL_REG3 = C8h
+  DRY active high on INT1 pin
+
+ */
+
+  Serial.println("init LIS3DSH Sensor");
+  SPI.begin(); 
+  SPI.setDataMode(SPI_MODE0);
+  SPI.setBitOrder(MSBFIRST);
+  //SPI.beginTransaction(SPISettings(8000000, MSBFIRST, SPI_MODE0));
+ 
+  digitalWrite(PE3, LOW);
+  uint8_t ret =SPI.transfer(CTRL_REG4); 
+  delay(1);
+  ret =SPI.transfer(0x77);  
+
+  //ret =SPI.transfer(CTRL_REG5); 
+  //delay(10);
+  //ret =SPI.transfer(0x0);  
+ 
+  digitalWrite(PE5, HIGH);
+  
+  /* read ID, expect 0x3F for LIS3DSH */
+  uint8_t id;
+  readReg(WHO_AM_I, &id); 
+  
+  Serial.print("ID=");
+  Serial.println(id, HEX);
+ 
+  Serial.println("...done");
+}
+
+void setup() {
+  
+  Serial.begin(230400);
+  pinMode(PE3, OUTPUT);
+  pinMode(PD15, OUTPUT);
+  pinMode(PD14, OUTPUT);
+  pinMode(PD13, OUTPUT);
+  
+  initSensor(); 
+}
+
+
+void loop() {
+  printXYZ();
+  delay(20);
+}
+