this version has all of Jim's fixes for reading the GPS and IMU data synchronously
Dependencies: MODSERIAL SDFileSystem mbed SDShell CRC CommHandler FP LinkedList LogUtil
ADIS16488.h
- Committer:
- jekain314
- Date:
- 2014-01-09
- Revision:
- 29:dead10cce6e9
- Parent:
- 22:1cbdbc856660
- Child:
- 30:96d133f3008e
File content as of revision 29:dead10cce6e9:
//set up the SPI on pins 5, 6, 7 to read from the ADIS16488 SPI spi(p5, p6, p7); // mosi (DIN), miso (DOUT), sclk (CLK) DigitalOut ADIS_CS(p8); //Chip Select for the ADIS SPI InterruptIn ADIS_DR(p28); //DataReady interrupt connected to DIO2 for ADIS DigitalOut ADIS_RST(p20); //ADIS reset pin bool IMUDataReady = false; int IMURecordCounter = 0; //see Table 9 from page 11 of the ADIS16488 spec //see fig 15 of spec -- note the low byte of the regsiter word is always zero // X_DELTANG_LOW, Y_DELTANG_LOW, X_DETANG_LOW, X_DELTVEL_LOW, Y_DELTVEL_LOW, Z_DELTVEL_LOW unsigned short LOW_REGISTER[] = {0x4000, 0x4400, 0x4800, 0x4C00, 0x5000, 0x5400}; // X_DELTANG_HIGH, Y_DELTANG_HIGH, X_DETANG_HIGH, X_DELTVEL_HIGH, Y_DELTVEL_HIGH, Z_DELTVEL_HIGH unsigned short HIGH_REGISTER[] = {0x4200, 0x4600, 0x4A00, 0x4E00, 0x5200, 0x5600}; volatile unsigned long IMUtimeFrom1PPS = 0; volatile int IMUClockCounter = 0; //counter for IMU samples per sec union WD { long dataWord; unsigned short pt[2];} wd; //IMU records are buffered in the IMUDataReady ISR const unsigned char IMUrecArraySize = 10; #pragma pack(1) struct IMUREC { unsigned long GPSTime; long dataWord[6]; }; IMUREC imuPing[IMUrecArraySize]; IMUREC imuPong[IMUrecArraySize]; IMUREC tempRec; volatile bool fillingPingWritingPong = true; unsigned long maxDelIMUmsecs = 0; unsigned long delIMUmsecs = 0; unsigned long lastIMUmsecs = 0; void IMUDataReadyISR(void) { IMUtimeFrom1PPS = timeFromPPS.read_us(); tempRec.GPSTime = GPSTimemsecs + PPSTimeOffset*1000 + IMUtimeFrom1PPS/1000.0; if (IMUClockCounter == IMUrecArraySize ) { IMUDataReady = true; fillingPingWritingPong = !fillingPingWritingPong; IMUClockCounter = 0; } spi.write((int) HIGH_REGISTER[0]); //next read will return results from HIGH_REGITER[0] for (int i=0; i<6; i++) //read the 6 rate and accel variables { wd.pt[1] = (unsigned short)spi.write((int) LOW_REGISTER[i]); if (i<5) // dont this on the last because this was pre-called { wd.pt[0] = (unsigned short)spi.write((int) HIGH_REGISTER[i+1]); } if ( fillingPingWritingPong) tempRec.dataWord[i] = wd.dataWord; //data word is a signed long else tempRec.dataWord[i] = wd.dataWord; //data word is a signed long } //fill the correct buffer ping or pong if (fillingPingWritingPong) imuPing[IMUClockCounter] = tempRec; else imuPong[IMUClockCounter] = tempRec; IMUClockCounter++; return; } void setupADIS(void) { ADIS_DR.mode(PullDown); ADIS_RST = 0; // set the IMU dataReady ISR ADIS_DR.rise(&IMUDataReadyISR); // Setup the mbed SPI for 16 bit data, high steady state clock, // second edge capture, with a 1MHz clock rate spi.format(16,3); spi.frequency(5000000); ADIS_CS = 1; //CS must be set high before it goes low cause the enable is the transition ADIS_RST = 1; wait(0.5); ADIS_CS = 0; //set the Chip select low to enable the IMU SPI access spi.write((int)0x8003); //change to page 3 //change the DECRATE to 98.4 Hz (this is also in page 3) //the 8 sets the high bit to 1 indicating a write to a register // The C abd D designate the registers for the DECRATE of Page 3 // The 0x17 sets the rate to: 2460/(23+1) = 102.5Hz // The 0x18 sets the rate to: 2460/(24+1) = 98.4Hz spi.write((int)0x8C17); //write high byte (only page number can be written in a single byte) spi.write((int)0x8D00); //write the low byte of DECRATE //to set the GPS VARF clock as the input synch clock for the IMU //the high byte is CD indicating the synch is enabled on the rising edge of the input clock //spi.write((int)0x86CD); //write high byte to register 0x06 //spi.write((int)0x8700); //write the low byte of 00 to registed 0x07 //change the page to 0 to get the data spi.write((int)0x8000); //change to page 0 }