Michael Walker / scp1000-D01

SCP1000-D01 MEMS pressure sensor library

scp1000.cpp@1:a45810688644, 2010-09-27 (annotated)

Committer:
MichaelW
Date:
Mon Sep 27 08:30:39 2010 +0000
Revision:
1:a45810688644
Parent:
0:dfe5ae6ea375
Child:
2:076ba33b1895
License info added

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MichaelW 1:a45810688644 1 /**
MichaelW 1:a45810688644 2 * @section LICENSE
MichaelW 1:a45810688644 3 *Copyright (c) 2010 ARM Ltd.
MichaelW 1:a45810688644 4 *
MichaelW 1:a45810688644 5 *Permission is hereby granted, free of charge, to any person obtaining a copy
MichaelW 1:a45810688644 6 *of this software and associated documentation files (the "Software"), to deal
MichaelW 1:a45810688644 7 *in the Software without restriction, including without limitation the rights
MichaelW 1:a45810688644 8 *to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
MichaelW 1:a45810688644 9 *copies of the Software, and to permit persons to whom the Software is
MichaelW 1:a45810688644 10 *furnished to do so, subject to the following conditions:
MichaelW 0:dfe5ae6ea375 11 *
MichaelW 1:a45810688644 12 *The above copyright notice and this permission notice shall be included in
MichaelW 1:a45810688644 13 *all copies or substantial portions of the Software.
MichaelW 1:a45810688644 14 *
MichaelW 1:a45810688644 15 *THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
MichaelW 1:a45810688644 16 *IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
MichaelW 1:a45810688644 17 *FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
MichaelW 1:a45810688644 18 *AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
MichaelW 1:a45810688644 19 *LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
MichaelW 1:a45810688644 20 *OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
MichaelW 1:a45810688644 21 *THE SOFTWARE.
MichaelW 1:a45810688644 22 *
MichaelW 1:a45810688644 23 *
MichaelW 1:a45810688644 24 * @section DESCRIPTION
MichaelW 1:a45810688644 25 *
MichaelW 0:dfe5ae6ea375 26 *
MichaelW 0:dfe5ae6ea375 27 */
MichaelW 0:dfe5ae6ea375 28
MichaelW 0:dfe5ae6ea375 29 #include "scp1000.h"
MichaelW 0:dfe5ae6ea375 30
MichaelW 0:dfe5ae6ea375 31 SCP1000::SCP1000(PinName mosi, PinName miso, PinName sck, PinName CSB):
MichaelW 0:dfe5ae6ea375 32 _spi(mosi, miso, sck),
MichaelW 0:dfe5ae6ea375 33 _CSB(CSB)
MichaelW 0:dfe5ae6ea375 34 /* _DRDY(NULL),
MichaelW 0:dfe5ae6ea375 35 _TRIG(Null),
MichaelW 0:dfe5ae6ea375 36 _PD(NULL)*/{
MichaelW 0:dfe5ae6ea375 37 _CSB = 1;
MichaelW 0:dfe5ae6ea375 38 wait(0.1);
MichaelW 0:dfe5ae6ea375 39 _CSB = 0;
MichaelW 0:dfe5ae6ea375 40 //Force reset
MichaelW 0:dfe5ae6ea375 41 _spi.write(((0x06<< 2) | 0x02));
MichaelW 0:dfe5ae6ea375 42 _spi.write(0x01);
MichaelW 0:dfe5ae6ea375 43 _CSB = 1;
MichaelW 0:dfe5ae6ea375 44 wait(0.06);
MichaelW 0:dfe5ae6ea375 45 _CSB = 0;
MichaelW 0:dfe5ae6ea375 46 //Check starup Procedure has finished
MichaelW 0:dfe5ae6ea375 47 int status;
MichaelW 0:dfe5ae6ea375 48 do{
MichaelW 0:dfe5ae6ea375 49 _spi.write(0x07 << 2);
MichaelW 0:dfe5ae6ea375 50 status = _spi.write(0x00);
MichaelW 0:dfe5ae6ea375 51 //printf("waiting for startup to finish %i\n", status);
MichaelW 0:dfe5ae6ea375 52 wait(0.1);
MichaelW 0:dfe5ae6ea375 53 }while((status & 0x01)); //Wait for LSB to go low
MichaelW 0:dfe5ae6ea375 54
MichaelW 0:dfe5ae6ea375 55 _spi.write(0x1F << 2);
MichaelW 0:dfe5ae6ea375 56 status = _spi.write(0x00);
MichaelW 0:dfe5ae6ea375 57 if(!(status & 0x01)){
MichaelW 0:dfe5ae6ea375 58 printf("Error in Intialisation");
MichaelW 0:dfe5ae6ea375 59 }
MichaelW 0:dfe5ae6ea375 60
MichaelW 0:dfe5ae6ea375 61
MichaelW 0:dfe5ae6ea375 62 //Set mode as 0x00
MichaelW 0:dfe5ae6ea375 63 _spi.write((0x03 << 2) | 0x02);
MichaelW 0:dfe5ae6ea375 64 _spi.write(0x00);
MichaelW 0:dfe5ae6ea375 65 wait(0.05);
MichaelW 0:dfe5ae6ea375 66
MichaelW 0:dfe5ae6ea375 67 //Check DRDDY is low, if not read data
MichaelW 0:dfe5ae6ea375 68 _spi.write(0x07 << 2);
MichaelW 0:dfe5ae6ea375 69 status = _spi.write(0x00);
MichaelW 0:dfe5ae6ea375 70 if(status & 0x20){
MichaelW 0:dfe5ae6ea375 71 printf("Data to be read");
MichaelW 0:dfe5ae6ea375 72 }
MichaelW 0:dfe5ae6ea375 73
MichaelW 0:dfe5ae6ea375 74 //Check OPStatus bit
MichaelW 0:dfe5ae6ea375 75 _spi.write(0x04 << 2);
MichaelW 0:dfe5ae6ea375 76 status = _spi.write(0x0);
MichaelW 0:dfe5ae6ea375 77 if(status & 0x01){
MichaelW 0:dfe5ae6ea375 78 printf("Not finished");
MichaelW 0:dfe5ae6ea375 79 }
MichaelW 0:dfe5ae6ea375 80
MichaelW 0:dfe5ae6ea375 81 //Activate new mode
MichaelW 0:dfe5ae6ea375 82 _spi.write((0x03 << 2) | 0x02);
MichaelW 0:dfe5ae6ea375 83 _spi.write(0x0A);
MichaelW 0:dfe5ae6ea375 84
MichaelW 0:dfe5ae6ea375 85
MichaelW 0:dfe5ae6ea375 86
MichaelW 0:dfe5ae6ea375 87 }
MichaelW 0:dfe5ae6ea375 88
MichaelW 0:dfe5ae6ea375 89
MichaelW 0:dfe5ae6ea375 90 void SCP1000::SetMode(SCPMode mode){
MichaelW 0:dfe5ae6ea375 91 _CSB = 0;
MichaelW 0:dfe5ae6ea375 92
MichaelW 0:dfe5ae6ea375 93
MichaelW 0:dfe5ae6ea375 94
MichaelW 0:dfe5ae6ea375 95 _CSB = 1;
MichaelW 0:dfe5ae6ea375 96
MichaelW 0:dfe5ae6ea375 97 }
MichaelW 0:dfe5ae6ea375 98
MichaelW 0:dfe5ae6ea375 99 float SCP1000::read(){
MichaelW 0:dfe5ae6ea375 100 _CSB = 0;
MichaelW 0:dfe5ae6ea375 101
MichaelW 0:dfe5ae6ea375 102 if(_isReady() == 1){
MichaelW 0:dfe5ae6ea375 103 _spi.write(0x1F <<2);
MichaelW 0:dfe5ae6ea375 104 int PressureHighest = _spi.write(0x00);
MichaelW 0:dfe5ae6ea375 105 _spi.write(0x20 <<2);
MichaelW 0:dfe5ae6ea375 106 int PressureHigh = _spi.write(0x00);
MichaelW 0:dfe5ae6ea375 107 int Pressurelow = _spi.write(0x00);
MichaelW 0:dfe5ae6ea375 108
MichaelW 0:dfe5ae6ea375 109
MichaelW 0:dfe5ae6ea375 110 int pressureValue = Pressurelow | PressureHigh << 8 | (PressureHighest & 0x07) << 16;
MichaelW 0:dfe5ae6ea375 111
MichaelW 0:dfe5ae6ea375 112 float pressure = ((float)pressureValue) / 4;
MichaelW 0:dfe5ae6ea375 113
MichaelW 0:dfe5ae6ea375 114 _CSB = 1;
MichaelW 0:dfe5ae6ea375 115
MichaelW 0:dfe5ae6ea375 116
MichaelW 0:dfe5ae6ea375 117 return(pressure);
MichaelW 0:dfe5ae6ea375 118 }else{
MichaelW 0:dfe5ae6ea375 119 return(0);
MichaelW 0:dfe5ae6ea375 120 }
MichaelW 0:dfe5ae6ea375 121 }
MichaelW 0:dfe5ae6ea375 122 float SCP1000::readTemperature(){
MichaelW 0:dfe5ae6ea375 123
MichaelW 0:dfe5ae6ea375 124 _CSB = 0;
MichaelW 0:dfe5ae6ea375 125
MichaelW 0:dfe5ae6ea375 126 if(_isReady() == 1){
MichaelW 0:dfe5ae6ea375 127 //ready so now read
MichaelW 0:dfe5ae6ea375 128 _spi.write(0x21 << 2);
MichaelW 0:dfe5ae6ea375 129 int TempHigh = _spi.write(0x00);
MichaelW 0:dfe5ae6ea375 130 int TempLow = _spi.write(0x00);
MichaelW 0:dfe5ae6ea375 131
MichaelW 0:dfe5ae6ea375 132 signed int temperatureValue = (TempLow | ((TempHigh & 0x1F) << 8));
MichaelW 0:dfe5ae6ea375 133 if(TempHigh & 0x20){
MichaelW 0:dfe5ae6ea375 134 //negative
MichaelW 0:dfe5ae6ea375 135 temperatureValue = -8192 + temperatureValue;
MichaelW 0:dfe5ae6ea375 136 }else{
MichaelW 0:dfe5ae6ea375 137 //positive
MichaelW 0:dfe5ae6ea375 138
MichaelW 0:dfe5ae6ea375 139 }
MichaelW 0:dfe5ae6ea375 140
MichaelW 0:dfe5ae6ea375 141 float temperature = ((float)temperatureValue) * 0.05;
MichaelW 0:dfe5ae6ea375 142 _CSB = 1;
MichaelW 0:dfe5ae6ea375 143 return(temperature);
MichaelW 0:dfe5ae6ea375 144 }else{
MichaelW 0:dfe5ae6ea375 145 return(0);
MichaelW 0:dfe5ae6ea375 146 }
MichaelW 0:dfe5ae6ea375 147 }
MichaelW 0:dfe5ae6ea375 148
MichaelW 0:dfe5ae6ea375 149 int SCP1000::_isReady(){
MichaelW 0:dfe5ae6ea375 150 //Depending on mode wait for it to be ready
MichaelW 0:dfe5ae6ea375 151 int status;
MichaelW 0:dfe5ae6ea375 152 _CSB = 0;
MichaelW 0:dfe5ae6ea375 153 do{
MichaelW 0:dfe5ae6ea375 154 _spi.write(0x07 << 2);
MichaelW 0:dfe5ae6ea375 155 status = _spi.write(0x00);
MichaelW 0:dfe5ae6ea375 156 //printf("waiting %i\n", status);
MichaelW 0:dfe5ae6ea375 157 wait(0.2);
MichaelW 0:dfe5ae6ea375 158 if(status & 0x10){
MichaelW 0:dfe5ae6ea375 159 //bit 4 high - real time error, interrupt has not been read in time - read DataRD16
MichaelW 0:dfe5ae6ea375 160 int temp;
MichaelW 0:dfe5ae6ea375 161 _spi.write(0x20 << 2);
MichaelW 0:dfe5ae6ea375 162 temp = _spi.write(0x00);
MichaelW 0:dfe5ae6ea375 163 temp = _spi.write(0x00);
MichaelW 0:dfe5ae6ea375 164 }
MichaelW 0:dfe5ae6ea375 165 }while(!(status & 0x20));
MichaelW 0:dfe5ae6ea375 166 return(1);
MichaelW 0:dfe5ae6ea375 167 }