Diff: perso/diver.h

Revision:

3:24069293d35d

Parent:

2:1d66e2e776bc

diff -r 1d66e2e776bc -r 24069293d35d perso/diver.h
--- a/perso/diver.h	Wed May 13 08:01:47 2015 +0000
+++ b/perso/diver.h	Tue Sep 15 16:09:10 2015 +0000
@@ -1,40 +1,44 @@
-// pour le moment ce sont des choses inutiles
+
+// pour lecture I2C  accelerometre 
+   PinName const SDA = PTE25;
+   PinName const SCL = PTE24; 
+   I2C i2c(SDA,SCL);
+
+#define REG_WHO_AM_I      0x0D
+#define REG_CTRL_REG_1    0x2A
+#define REG_OUT_X_MSB     0x01
+#define REG_OUT_Y_MSB     0x03
+#define REG_OUT_Z_MSB     0x05
+
+#define MMA8451_I2C_ADDRESS (0x1d<<1)
+
+// #define UINT14_MAX        16383
+#define UINT14_MAX        16384
 
 
-/*#if defined(TARGET_LPC11U24)    //SEEEDUINO_ARCH
-#define PIN_XP          P0_14
-#define PIN_XM          P0_12
-#define PIN_YP          P0_13
-#define PIN_YM          P0_11
-#define PIN_MOSI        P1_22
-#define PIN_MISO        P1_21
-#define PIN_SCLK        P1_20
-#define PIN_CS_TFT      P1_24
-#define PIN_DC_TFT      P1_25
-#define PIN_BL_TFT      P1_5
-#define PIN_CS_SD       P1_18
-#elif defined(TARGET_LPC1768)   //SEEEDUINO_ARCH_PRO
-#define PIN_XP          P0_26
-#define PIN_XM          P0_24
-#define PIN_YP          P0_25
-#define PIN_YM          P0_23
-#define PIN_MOSI        P0_18
-#define PIN_MISO        P0_17
-#define PIN_SCLK        P0_15
-#define PIN_CS_TFT      P2_3
-#define PIN_DC_TFT      P2_4
-#define PIN_BL_TFT      P2_5
-#define PIN_CS_SD       P2_2
-#else //please redefine the following pins
-#define PIN_XP
-#define PIN_XM
-#define PIN_YP
-#define PIN_YM
-#define PIN_MOSI
-#define PIN_MISO
-#define PIN_SCLK
-#define PIN_CS_TFT
-#define PIN_DC_TFT
-#define PIN_BL_TFT
-#define PIN_CS_SD
-#endif*/
+static const float redx=0.0f;
+static const float redy=1.0f;
+static const float greenx=sqrt(3.0f)/2.0f;
+static const float greeny=-0.5f;
+static const float bluex=-sqrt(3.0f)/2.0f;
+static const float bluey=-0.5f;
+
+static const float twothirds=2.0f/3.0f;
+
+
+float acclnread(uint8_t reg)
+{
+  // Normalisation here seems wrong
+  char t[1]= {reg};
+  i2c.write(MMA8451_I2C_ADDRESS,t,1,true);
+  uint8_t xbits[2] = {0,0};
+  i2c.read(MMA8451_I2C_ADDRESS,(char *)xbits,2);
+  int16_t xint = 0;
+  xint=(xbits[0]<<6)|(xbits[1]>>2);
+  // this sign flip code looks wrong, UINT14_MAX maps to 0
+  // UINT14_MAX=16383, should it be UINT14_MAX=16384 
+  if (xint > UINT14_MAX>>1)
+    xint -= UINT14_MAX;
+  return float(xint)/4096.0f;
+  //  return float(xint);
+}