Chandra Tjhai / Mbed 2 deprecated ENGO333_Lab_tiltmeter

Simple tiltmeter using accelerometer

Dependencies:   mbed C12832

ENGO333_MMA7660.cpp@0:7d6134e052e0, 2019-11-23 (annotated)

Committer:
chtjhai
Date:
Sat Nov 23 04:58:09 2019 +0000
Revision:
0:7d6134e052e0
Simple tiltmeter using accelerometer

Who changed what in which revision?

UserRevisionLine numberNew contents of line
chtjhai 0:7d6134e052e0 1 #include "ENGO333_MMA7660.h"
chtjhai 0:7d6134e052e0 2
chtjhai 0:7d6134e052e0 3 const float GRAVITY = 9.8086;
chtjhai 0:7d6134e052e0 4
chtjhai 0:7d6134e052e0 5 ENGO333_MMA7660::ENGO333_MMA7660() : i2c(p28, p27)
chtjhai 0:7d6134e052e0 6 {
chtjhai 0:7d6134e052e0 7 SetActiveMode();
chtjhai 0:7d6134e052e0 8 SetSamplingRateAM(MMA7660_AMSR8);
chtjhai 0:7d6134e052e0 9 measAccel[0] = measAccel[1] = measAccel[2] = 0;
chtjhai 0:7d6134e052e0 10 }
chtjhai 0:7d6134e052e0 11
chtjhai 0:7d6134e052e0 12 bool ENGO333_MMA7660::TestConnection()
chtjhai 0:7d6134e052e0 13 {
chtjhai 0:7d6134e052e0 14 char data[3] = {128, 128, 128};
chtjhai 0:7d6134e052e0 15 bool alert;
chtjhai 0:7d6134e052e0 16
chtjhai 0:7d6134e052e0 17 // Check data validity
chtjhai 0:7d6134e052e0 18 alert = false;
chtjhai 0:7d6134e052e0 19 i2c.readBytes(MMA7660_ADDRESS, MMA7660_XOUT_REG, data, 3);
chtjhai 0:7d6134e052e0 20 for (int i = 0; i < 3; ++i) {
chtjhai 0:7d6134e052e0 21 if (data[i] > 63)
chtjhai 0:7d6134e052e0 22 alert = true;
chtjhai 0:7d6134e052e0 23 }
chtjhai 0:7d6134e052e0 24
chtjhai 0:7d6134e052e0 25 if (alert == false) {
chtjhai 0:7d6134e052e0 26 return true;
chtjhai 0:7d6134e052e0 27 } else {
chtjhai 0:7d6134e052e0 28 return false;
chtjhai 0:7d6134e052e0 29 }
chtjhai 0:7d6134e052e0 30 }
chtjhai 0:7d6134e052e0 31
chtjhai 0:7d6134e052e0 32 void ENGO333_MMA7660::SetActiveMode()
chtjhai 0:7d6134e052e0 33 {
chtjhai 0:7d6134e052e0 34 i2c.writeOneByte(MMA7660_ADDRESS, MMA7660_MODE_REG, 0x01);
chtjhai 0:7d6134e052e0 35 }
chtjhai 0:7d6134e052e0 36
chtjhai 0:7d6134e052e0 37 void ENGO333_MMA7660::SetSamplingRateAM(MMA7660_AMSR_t samplingRate)
chtjhai 0:7d6134e052e0 38 {
chtjhai 0:7d6134e052e0 39 char oldValue, newValue;
chtjhai 0:7d6134e052e0 40 oldValue = i2c.readOneByte(MMA7660_ADDRESS, MMA7660_SR_REG);
chtjhai 0:7d6134e052e0 41 oldValue = oldValue & 0x07;
chtjhai 0:7d6134e052e0 42 newValue = oldValue | samplingRate;
chtjhai 0:7d6134e052e0 43 i2c.writeOneByte(MMA7660_ADDRESS, MMA7660_SR_REG, newValue);
chtjhai 0:7d6134e052e0 44 }
chtjhai 0:7d6134e052e0 45
chtjhai 0:7d6134e052e0 46 void ENGO333_MMA7660::ReadAccelerometers()
chtjhai 0:7d6134e052e0 47 {
chtjhai 0:7d6134e052e0 48 char data[3];
chtjhai 0:7d6134e052e0 49 bool alert;
chtjhai 0:7d6134e052e0 50
chtjhai 0:7d6134e052e0 51 // Check data validity
chtjhai 0:7d6134e052e0 52 do {
chtjhai 0:7d6134e052e0 53 alert = false;
chtjhai 0:7d6134e052e0 54 i2c.readBytes(MMA7660_ADDRESS, MMA7660_XOUT_REG, data, 3);
chtjhai 0:7d6134e052e0 55 for (int i = 0; i < 3; ++i) {
chtjhai 0:7d6134e052e0 56 if (data[i] > 63)
chtjhai 0:7d6134e052e0 57 alert = true;
chtjhai 0:7d6134e052e0 58 if (data[i] > 31)
chtjhai 0:7d6134e052e0 59 data[i] += 128 + 64;
chtjhai 0:7d6134e052e0 60 }
chtjhai 0:7d6134e052e0 61 } while (alert);
chtjhai 0:7d6134e052e0 62
chtjhai 0:7d6134e052e0 63 measAccel[0] = (signed char)(data[0]) / MMA7660_SCALE * GRAVITY;
chtjhai 0:7d6134e052e0 64 measAccel[1] = (signed char)(data[1]) / MMA7660_SCALE * GRAVITY;
chtjhai 0:7d6134e052e0 65 measAccel[2] = (signed char)(data[2]) / MMA7660_SCALE * GRAVITY;
chtjhai 0:7d6134e052e0 66 }
chtjhai 0:7d6134e052e0 67
chtjhai 0:7d6134e052e0 68 float ENGO333_MMA7660::GetAccelX() const
chtjhai 0:7d6134e052e0 69 {
chtjhai 0:7d6134e052e0 70 return measAccel[0];
chtjhai 0:7d6134e052e0 71 }
chtjhai 0:7d6134e052e0 72
chtjhai 0:7d6134e052e0 73 float ENGO333_MMA7660::GetAccelY() const
chtjhai 0:7d6134e052e0 74 {
chtjhai 0:7d6134e052e0 75 return measAccel[1];
chtjhai 0:7d6134e052e0 76 }
chtjhai 0:7d6134e052e0 77
chtjhai 0:7d6134e052e0 78 float ENGO333_MMA7660::GetAccelZ() const
chtjhai 0:7d6134e052e0 79 {
chtjhai 0:7d6134e052e0 80 return measAccel[2];
chtjhai 0:7d6134e052e0 81 }
chtjhai 0:7d6134e052e0 82
chtjhai 0:7d6134e052e0 83