David Summers / Mbed 2 deprecated MS5611

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Dependencies:   mbed

main.cpp@3:a8c38c3fe967, 2018-03-16 (annotated)

Committer:
summers
Date:
Fri Mar 16 18:35:06 2018 +0000
Revision:
3:a8c38c3fe967
Parent:
2:b6a0d4ba24a1
Child:
4:e0dbf2bdb967
This reads D1 and D2 correctly and does the conversion

Who changed what in which revision?

UserRevisionLine numberNew contents of line
summers 0:9146d1e52be0 1 #include "mbed.h"
summers 1:3295382ddc81 2 #include "main.h"
summers 0:9146d1e52be0 3
summers 1:3295382ddc81 4 Serial pc(SERIAL_TX, SERIAL_RX, 115200); // tx, rx
summers 1:3295382ddc81 5 //DigitalOut led(LED_RED);
summers 1:3295382ddc81 6 //SPI spi(PTC6,PTC7,PTD1,PTC0);
summers 1:3295382ddc81 7 //SPI spi(PTC6,PTC7,PTD1); // my prefered, but mixed
summers 1:3295382ddc81 8 SPI spi(PTC6,PTC7,PTC5); // PTC5 - the LED
summers 1:3295382ddc81 9 //SPI spi(PTD2,PTD3,PTD1);
summers 1:3295382ddc81 10 DigitalOut cs(PTC0);
summers 0:9146d1e52be0 11
summers 0:9146d1e52be0 12 int main()
summers 0:9146d1e52be0 13 {
summers 1:3295382ddc81 14 int PROM[8];
summers 2:b6a0d4ba24a1 15 uint32_t D1,D2;
summers 2:b6a0d4ba24a1 16 double T,P;
summers 1:3295382ddc81 17 cs.write(1); // disable all SPI
summers 2:b6a0d4ba24a1 18 pc.printf("Hello World!\r\n");
summers 1:3295382ddc81 19 MS5611_init(PROM);
summers 1:3295382ddc81 20 for (int i=0; i<8; i++) {
summers 2:b6a0d4ba24a1 21 pc.printf("Prom(%i): %i\r\n",i,PROM[i]);
summers 1:3295382ddc81 22 }
summers 3:a8c38c3fe967 23
summers 3:a8c38c3fe967 24 while (1) {
summers 2:b6a0d4ba24a1 25 // the third paramater gives over samping
summers 2:b6a0d4ba24a1 26 // 0 - 256
summers 2:b6a0d4ba24a1 27 // 1 - 512
summers 2:b6a0d4ba24a1 28 // 2 - 1024
summers 2:b6a0d4ba24a1 29 // 3 - 2048
summers 2:b6a0d4ba24a1 30 // 4 - 4096
summers 2:b6a0d4ba24a1 31 MS5611(&D1,&D2,4);
summers 2:b6a0d4ba24a1 32 pc.printf("D1 = %i\r\nD2 = %i\r\n",D1,D2);
summers 2:b6a0d4ba24a1 33
summers 2:b6a0d4ba24a1 34 MS5611_phys(D1,D2,PROM,&T,&P);
summers 2:b6a0d4ba24a1 35
summers 2:b6a0d4ba24a1 36 pc.printf("Temperature = %f deg C\r\n",T/100.0);
summers 2:b6a0d4ba24a1 37 pc.printf("Pressure = %f mbar\r\n",P/100.0);
summers 2:b6a0d4ba24a1 38
summers 3:a8c38c3fe967 39 wait(10.0);
summers 3:a8c38c3fe967 40 }
summers 1:3295382ddc81 41 }
summers 1:3295382ddc81 42
summers 1:3295382ddc81 43 void MS5611_init(int *PROM)
summers 1:3295382ddc81 44 {
summers 3:a8c38c3fe967 45 uint32_t crc=0;
summers 1:3295382ddc81 46 spi.format(8,0); // 8 bit mode 0 - this is default anyway but good to code.
summers 1:3295382ddc81 47 spi.frequency(1000000); // 1MHz is this the minimum?
summers 1:3295382ddc81 48 cs.write(0); // Enable the MS5611 intercae
summers 2:b6a0d4ba24a1 49 if (spi.write(0x1E)!=0xfe) {
summers 2:b6a0d4ba24a1 50 pc.printf("Error reseting the device\r\n");
summers 2:b6a0d4ba24a1 51 }
summers 1:3295382ddc81 52 wait_ms(3); // give time for ROM to reload 2.8ms by the spec
summers 2:b6a0d4ba24a1 53 cs.write(1); // close the connection - does it finish the command?
summers 2:b6a0d4ba24a1 54 wait_us(10); // Pause after putting CSB high
summers 1:3295382ddc81 55 for (int i=0; i<8; i++) {
summers 2:b6a0d4ba24a1 56 cs.write(0); // enable the SC to start a command.
summers 2:b6a0d4ba24a1 57 if (spi.write(0xA0|(i<<1))!=0xfe) {
summers 2:b6a0d4ba24a1 58 pc.printf("Error reading prom(%i)\r\n",i);
summers 2:b6a0d4ba24a1 59 }
summers 1:3295382ddc81 60 register uint8_t promh=spi.write(0x00);
summers 1:3295382ddc81 61 register uint8_t proml=spi.write(0x00);
summers 2:b6a0d4ba24a1 62 cs.write(1); // disable CS to finish the command
summers 1:3295382ddc81 63 PROM[i]=((promh<<8)|(proml));
summers 3:a8c38c3fe967 64 crc|=(i==7)?(PROM[i]&0xff00):PROM[i]; // Note AN520 gives this bit mask
summers 2:b6a0d4ba24a1 65 for (int j=0; j<16; j++) {
summers 2:b6a0d4ba24a1 66 crc=crc<<1;
summers 2:b6a0d4ba24a1 67 if (crc&0x1000000) { // implimt the CRC4 algorithm 0x13 -
summers 3:a8c38c3fe967 68 crc^=0x1300000; // This won't do the last 4 bits of PROM7
summers 2:b6a0d4ba24a1 69 }
summers 2:b6a0d4ba24a1 70 }
summers 2:b6a0d4ba24a1 71 wait_us(10); // Pause probably not stricly needed, but after switching CSB high give a bit of time.
summers 1:3295382ddc81 72 }
summers 2:b6a0d4ba24a1 73 if ((crc>>20)!=(PROM[7]&0xf))
summers 2:b6a0d4ba24a1 74 pc.printf("CRC check sum: %x vs recorded %x\r\n",crc>>20,PROM[7]&0xf);
summers 1:3295382ddc81 75 }
summers 1:3295382ddc81 76
summers 2:b6a0d4ba24a1 77 void MS5611(uint32_t *D1, uint32_t *D2, int os)
summers 1:3295382ddc81 78 {
summers 1:3295382ddc81 79 // cs.write(0);
summers 1:3295382ddc81 80 spi.format(8,0);
summers 1:3295382ddc81 81 spi.frequency(1000000);
summers 2:b6a0d4ba24a1 82 cs.write(0); // Enable the MS5611 intercae
summers 2:b6a0d4ba24a1 83 if (spi.write(0x1E)!=0xfe) { // and reset the device
summers 2:b6a0d4ba24a1 84 pc.printf("Error reseting the device\r\n");
summers 2:b6a0d4ba24a1 85 }
summers 2:b6a0d4ba24a1 86 wait_ms(3); // give time for ROM to reload 2.8ms by the spec
summers 2:b6a0d4ba24a1 87 cs.write(1); // close the connection - does it finish the command?
summers 2:b6a0d4ba24a1 88 wait_us(10); // Pause after putting CSB high
summers 2:b6a0d4ba24a1 89 cs.write(0); // Enable the MS5611 intercae
summers 2:b6a0d4ba24a1 90 if (spi.write(0x40|(os<<1))!=0xfe) { // D1 please
summers 2:b6a0d4ba24a1 91 pc.printf("Error asking for D1\r\n");
summers 2:b6a0d4ba24a1 92 }
summers 2:b6a0d4ba24a1 93 cs.write(1); // Disable the MS5611 intercae
summers 2:b6a0d4ba24a1 94 wait_us(600*(1<<os)); // pause for read, longer when oversampling
summers 2:b6a0d4ba24a1 95 cs.write(0); // Enable the MS5611 intercae
summers 3:a8c38c3fe967 96 if(spi.write(0x00)!=0xfe) { // can I have the result?;
summers 3:a8c38c3fe967 97 pc.printf("Error reading D1\r\n");
summers 3:a8c38c3fe967 98 }
summers 2:b6a0d4ba24a1 99 register uint8_t d1h=spi.write(0x00);
summers 2:b6a0d4ba24a1 100 register uint8_t d1m=spi.write(0x00);
summers 2:b6a0d4ba24a1 101 register uint8_t d1l=spi.write(0x00);
summers 2:b6a0d4ba24a1 102 cs.write(1); // and terminate the command
summers 2:b6a0d4ba24a1 103 wait_us(10); // Pause after putting CSB high
summers 2:b6a0d4ba24a1 104 cs.write(0); // Enable the MS5611 intercae
summers 2:b6a0d4ba24a1 105 if (spi.write(0x50|(os<<1))!=0xfe) { // D2 please
summers 2:b6a0d4ba24a1 106 pc.printf("Error asking for D2\r\n");
summers 2:b6a0d4ba24a1 107 }
summers 2:b6a0d4ba24a1 108 cs.write(1); // Disable the MS5611 intercae
summers 2:b6a0d4ba24a1 109 wait_us(600*(1<<os)); // pause for read, longer when oversampling
summers 2:b6a0d4ba24a1 110 cs.write(0); // Enable the MS5611 intercae
summers 3:a8c38c3fe967 111 if(spi.write(0x00)!=0xfe) { // can I have the result?;
summers 3:a8c38c3fe967 112 pc.printf("Error reading D2\r\n");
summers 3:a8c38c3fe967 113 }
summers 2:b6a0d4ba24a1 114 register uint8_t d2h=spi.write(0x00);
summers 2:b6a0d4ba24a1 115 register uint8_t d2m=spi.write(0x00);
summers 2:b6a0d4ba24a1 116 register uint8_t d2l=spi.write(0x00);
summers 2:b6a0d4ba24a1 117 cs.write(1); // and terminate the command
summers 2:b6a0d4ba24a1 118 *D1=((uint32_t) d1h<<16)|((uint32_t) d1m<<8)|((uint32_t) d1l);
summers 2:b6a0d4ba24a1 119 *D2=((uint32_t) d2h<<16)|((uint32_t) d2m<<8)|((uint32_t) d2l);
summers 2:b6a0d4ba24a1 120 }
summers 2:b6a0d4ba24a1 121
summers 2:b6a0d4ba24a1 122 void MS5611_phys(uint32_t D1,uint32_t D2, int *PROM, double *T, double *P)
summers 2:b6a0d4ba24a1 123 {
summers 3:a8c38c3fe967 124 int64_t dt=((int64_t) D2)-(((int64_t) PROM[5])<<8);
summers 2:b6a0d4ba24a1 125 *T=2000.0+((double) dt*PROM[6])/8388608.0;
summers 3:a8c38c3fe967 126 int64_t off=(((int64_t) PROM[2])<<16)+((((int64_t) PROM[4])*dt)>>7);
summers 3:a8c38c3fe967 127 int64_t sens=(((int64_t) PROM[1])<<15)+((((int64_t) PROM[3])*dt)>>8);
summers 3:a8c38c3fe967 128 *P=(((double) D1)*((double) sens)/2097152.0-((double) off))/32768.0;
summers 0:9146d1e52be0 129 }