SCP1000-D01 MEMS pressure sensor library
scp1000.cpp@4:d509ab38e2b5, 2010-09-28 (annotated)
- Committer:
- MichaelW
- Date:
- Tue Sep 28 08:28:48 2010 +0000
- Revision:
- 4:d509ab38e2b5
- Parent:
- 3:29c98bdee20b
Code improvements
Who changed what in which revision?
User | Revision | Line number | New contents of line |
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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 | 3:29c98bdee20b | 25 | * Library for using the SCP1000-D01 MEMS Pressure sensor, this is the SPI version. This library only supports high resolution mode. |
MichaelW | 3:29c98bdee20b | 26 | * Communication with the sensor is via a 4 wire interface |
MichaelW | 0:dfe5ae6ea375 | 27 | * |
MichaelW | 0:dfe5ae6ea375 | 28 | */ |
MichaelW | 0:dfe5ae6ea375 | 29 | |
MichaelW | 0:dfe5ae6ea375 | 30 | #include "scp1000.h" |
MichaelW | 0:dfe5ae6ea375 | 31 | |
MichaelW | 0:dfe5ae6ea375 | 32 | SCP1000::SCP1000(PinName mosi, PinName miso, PinName sck, PinName CSB): |
MichaelW | 0:dfe5ae6ea375 | 33 | _spi(mosi, miso, sck), |
MichaelW | 0:dfe5ae6ea375 | 34 | _CSB(CSB) |
MichaelW | 3:29c98bdee20b | 35 | { |
MichaelW | 0:dfe5ae6ea375 | 36 | _CSB = 1; |
MichaelW | 0:dfe5ae6ea375 | 37 | wait(0.1); |
MichaelW | 0:dfe5ae6ea375 | 38 | _CSB = 0; |
MichaelW | 0:dfe5ae6ea375 | 39 | //Force reset |
MichaelW | 0:dfe5ae6ea375 | 40 | _spi.write(((0x06<< 2) | 0x02)); |
MichaelW | 0:dfe5ae6ea375 | 41 | _spi.write(0x01); |
MichaelW | 0:dfe5ae6ea375 | 42 | _CSB = 1; |
MichaelW | 0:dfe5ae6ea375 | 43 | wait(0.06); |
MichaelW | 0:dfe5ae6ea375 | 44 | _CSB = 0; |
MichaelW | 0:dfe5ae6ea375 | 45 | //Check starup Procedure has finished |
MichaelW | 0:dfe5ae6ea375 | 46 | int status; |
MichaelW | 0:dfe5ae6ea375 | 47 | do{ |
MichaelW | 0:dfe5ae6ea375 | 48 | _spi.write(0x07 << 2); |
MichaelW | 0:dfe5ae6ea375 | 49 | status = _spi.write(0x00); |
MichaelW | 0:dfe5ae6ea375 | 50 | //printf("waiting for startup to finish %i\n", status); |
MichaelW | 0:dfe5ae6ea375 | 51 | wait(0.1); |
MichaelW | 0:dfe5ae6ea375 | 52 | }while((status & 0x01)); //Wait for LSB to go low |
MichaelW | 4:d509ab38e2b5 | 53 | //Test for error in intialisation |
MichaelW | 0:dfe5ae6ea375 | 54 | _spi.write(0x1F << 2); |
MichaelW | 0:dfe5ae6ea375 | 55 | status = _spi.write(0x00); |
MichaelW | 0:dfe5ae6ea375 | 56 | if(!(status & 0x01)){ |
MichaelW | 4:d509ab38e2b5 | 57 | //printf("Error in Intialisation"); |
MichaelW | 4:d509ab38e2b5 | 58 | return; |
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 | 4:d509ab38e2b5 | 71 | //printf("Data to be read"); |
MichaelW | 4:d509ab38e2b5 | 72 | _spi.write(0x1F <<2); |
MichaelW | 4:d509ab38e2b5 | 73 | _spi.write(0x00); //read and discard data |
MichaelW | 4:d509ab38e2b5 | 74 | _spi.write(0x20 <<2); |
MichaelW | 4:d509ab38e2b5 | 75 | _spi.write(0x00); //read and discard data |
MichaelW | 4:d509ab38e2b5 | 76 | _spi.write(0x00); //read and discard data |
MichaelW | 0:dfe5ae6ea375 | 77 | } |
MichaelW | 0:dfe5ae6ea375 | 78 | |
MichaelW | 0:dfe5ae6ea375 | 79 | //Check OPStatus bit |
MichaelW | 0:dfe5ae6ea375 | 80 | _spi.write(0x04 << 2); |
MichaelW | 0:dfe5ae6ea375 | 81 | status = _spi.write(0x0); |
MichaelW | 0:dfe5ae6ea375 | 82 | if(status & 0x01){ |
MichaelW | 4:d509ab38e2b5 | 83 | //printf("Not finished"); |
MichaelW | 0:dfe5ae6ea375 | 84 | } |
MichaelW | 0:dfe5ae6ea375 | 85 | |
MichaelW | 0:dfe5ae6ea375 | 86 | //Activate new mode |
MichaelW | 0:dfe5ae6ea375 | 87 | _spi.write((0x03 << 2) | 0x02); |
MichaelW | 0:dfe5ae6ea375 | 88 | _spi.write(0x0A); |
MichaelW | 0:dfe5ae6ea375 | 89 | } |
MichaelW | 0:dfe5ae6ea375 | 90 | float SCP1000::read(){ |
MichaelW | 0:dfe5ae6ea375 | 91 | _CSB = 0; |
MichaelW | 0:dfe5ae6ea375 | 92 | |
MichaelW | 2:076ba33b1895 | 93 | if(_waitReady() == 1){ |
MichaelW | 0:dfe5ae6ea375 | 94 | _spi.write(0x1F <<2); |
MichaelW | 0:dfe5ae6ea375 | 95 | int PressureHighest = _spi.write(0x00); |
MichaelW | 0:dfe5ae6ea375 | 96 | _spi.write(0x20 <<2); |
MichaelW | 0:dfe5ae6ea375 | 97 | int PressureHigh = _spi.write(0x00); |
MichaelW | 0:dfe5ae6ea375 | 98 | int Pressurelow = _spi.write(0x00); |
MichaelW | 0:dfe5ae6ea375 | 99 | |
MichaelW | 4:d509ab38e2b5 | 100 | int pressureValue = Pressurelow | PressureHigh << 8 | (PressureHighest & 0x07) << 16; |
MichaelW | 0:dfe5ae6ea375 | 101 | float pressure = ((float)pressureValue) / 4; |
MichaelW | 4:d509ab38e2b5 | 102 | |
MichaelW | 0:dfe5ae6ea375 | 103 | _CSB = 1; |
MichaelW | 4:d509ab38e2b5 | 104 | |
MichaelW | 0:dfe5ae6ea375 | 105 | return(pressure); |
MichaelW | 0:dfe5ae6ea375 | 106 | }else{ |
MichaelW | 0:dfe5ae6ea375 | 107 | return(0); |
MichaelW | 0:dfe5ae6ea375 | 108 | } |
MichaelW | 0:dfe5ae6ea375 | 109 | } |
MichaelW | 0:dfe5ae6ea375 | 110 | float SCP1000::readTemperature(){ |
MichaelW | 0:dfe5ae6ea375 | 111 | |
MichaelW | 0:dfe5ae6ea375 | 112 | _CSB = 0; |
MichaelW | 0:dfe5ae6ea375 | 113 | |
MichaelW | 2:076ba33b1895 | 114 | if(_waitReady() == 1){ |
MichaelW | 0:dfe5ae6ea375 | 115 | //ready so now read |
MichaelW | 0:dfe5ae6ea375 | 116 | _spi.write(0x21 << 2); |
MichaelW | 0:dfe5ae6ea375 | 117 | int TempHigh = _spi.write(0x00); |
MichaelW | 0:dfe5ae6ea375 | 118 | int TempLow = _spi.write(0x00); |
MichaelW | 0:dfe5ae6ea375 | 119 | |
MichaelW | 0:dfe5ae6ea375 | 120 | signed int temperatureValue = (TempLow | ((TempHigh & 0x1F) << 8)); |
MichaelW | 0:dfe5ae6ea375 | 121 | if(TempHigh & 0x20){ |
MichaelW | 0:dfe5ae6ea375 | 122 | //negative |
MichaelW | 0:dfe5ae6ea375 | 123 | temperatureValue = -8192 + temperatureValue; |
MichaelW | 0:dfe5ae6ea375 | 124 | }else{ |
MichaelW | 4:d509ab38e2b5 | 125 | //positive |
MichaelW | 0:dfe5ae6ea375 | 126 | } |
MichaelW | 4:d509ab38e2b5 | 127 | |
MichaelW | 0:dfe5ae6ea375 | 128 | float temperature = ((float)temperatureValue) * 0.05; |
MichaelW | 0:dfe5ae6ea375 | 129 | _CSB = 1; |
MichaelW | 0:dfe5ae6ea375 | 130 | return(temperature); |
MichaelW | 0:dfe5ae6ea375 | 131 | }else{ |
MichaelW | 0:dfe5ae6ea375 | 132 | return(0); |
MichaelW | 0:dfe5ae6ea375 | 133 | } |
MichaelW | 0:dfe5ae6ea375 | 134 | } |
MichaelW | 0:dfe5ae6ea375 | 135 | |
MichaelW | 2:076ba33b1895 | 136 | int SCP1000::_waitReady(){ |
MichaelW | 4:d509ab38e2b5 | 137 | //Depending on mode wait for it to be ready - only supports high resolution mode - wait for bit 5 to be set in 00 |
MichaelW | 0:dfe5ae6ea375 | 138 | int status; |
MichaelW | 0:dfe5ae6ea375 | 139 | _CSB = 0; |
MichaelW | 0:dfe5ae6ea375 | 140 | do{ |
MichaelW | 0:dfe5ae6ea375 | 141 | _spi.write(0x07 << 2); |
MichaelW | 0:dfe5ae6ea375 | 142 | status = _spi.write(0x00); |
MichaelW | 0:dfe5ae6ea375 | 143 | //printf("waiting %i\n", status); |
MichaelW | 0:dfe5ae6ea375 | 144 | wait(0.2); |
MichaelW | 0:dfe5ae6ea375 | 145 | if(status & 0x10){ |
MichaelW | 0:dfe5ae6ea375 | 146 | //bit 4 high - real time error, interrupt has not been read in time - read DataRD16 |
MichaelW | 0:dfe5ae6ea375 | 147 | _spi.write(0x20 << 2); |
MichaelW | 3:29c98bdee20b | 148 | int data = _spi.write(0x00); |
MichaelW | 3:29c98bdee20b | 149 | data = _spi.write(0x00); |
MichaelW | 0:dfe5ae6ea375 | 150 | } |
MichaelW | 0:dfe5ae6ea375 | 151 | }while(!(status & 0x20)); |
MichaelW | 2:076ba33b1895 | 152 | return(1); |
MichaelW | 0:dfe5ae6ea375 | 153 | } |