Re: Gyro L3G4200D Code Request
Here's part of some code for ST's LSM330DLC that looks like it has all the same registers for your gyroscope. Be sure to correct the address for your device.
Since it's a lengthy program, I'll just list the basic functions.
I used the MSSP module of the PIC18F14K50 so it can run in the background.
The read routine was called using the DRDY interrupt output of the device.
MSSP config:
Gyro register configs:Code:SSPSTAT.7 = 0 ' Slew rate control set to 400KHz SSPSTAT.6 = 0 ' SMBus compliance disabled SSPCON1 = %00101000 ' Enbles I2C module and Master mode SSPADD = $1A ' Baud rate clock divider bits set for 400KHz ' Adjusted from $1D = 368KHz CLEAR ' Set all registers to 0 XYZ_RAM VAR BYTE[12] ' Array for 16 bit data, 2 bytes each. First 6 for accelerometer, last 6 for gyro
Gyro register reading routine:Code:'========================================================================= ' Gyroscope configuration ' Load time for all 13 Registers is 1029us at 400KHz setting ' Registers loaded in order specified by data sheet: ' 1. Write CTRL_REG2 ' 2. Write CTRL_REG3 ' 3. Write CTRL_REG4 ' 4. Write CTRL_REG5 ' 5. Write Reference ' 6. Write INT1_THS ' 7. Write INT1_DUR ' 8. Write INT1_CFG ' 9. Write CTRL_REG5 ' 10. Write CTRL_REG1 '========================================================================= Config_Gyr: ' Load CTRL_REG2: 10100111, Edge sensitive trigger, HP filter = Normal, ' HP cutoff = 0.09Hz GOSUB Start_Gyr ' Adresss the device SSPBUF = $21 ' Transmit register address WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task SSPBUF = %10100111 ' Transmit the 8bit data to register WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task PIR1.3 = 0 ' Clear interrupt flag GOSUB Stop_I2C ' Complete TX data ' Load CTRL_REG3: 10000000, INT1_G enabled, no Boot Status, Active High, ' Push-pull output. INT2_G disabled GOSUB Start_Gyr ' Adresss the device SSPBUF = $22 ' Transmit register address WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task SSPBUF = %00000000 ' Transmit the 8bit data to register WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task PIR1.3 = 0 ' Clear interrupt flag GOSUB Stop_I2C ' Complete TX data ' Load CTRL_REG4: 01110000, cont. update, MSB @ lower address, 2000dps ' non SPI GOSUB Start_Gyr ' Adresss the device SSPBUF = $23 ' Transmit register address WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task SSPBUF = %01110000 ' Transmit the 8bit data to register WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task PIR1.3 = 0 ' Clear interrupt flag GOSUB Stop_I2C ' Complete TX data '////////////////// XYZ Interrupt threshold settings //////////////////// ' Threshold level = THS / 0.061dps, where THS = 540dps (1.5 turns/sec) ' Maximum threshold level is 1/2 of Full Scale ' 14bit result is loaded into HI/LO registers of each axis '//////////////////////////////////////////////////////////////////////// ' Load INT1_THS_XH: 00100010, Interrupt MSB threshold bits 14:8 GOSUB Start_Gyr ' Adresss the device SSPBUF = $32 ' Transmit register address WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task SSPBUF = %00100010 ' Transmit the 8bit data to register WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task PIR1.3 = 0 ' Clear interrupt flag GOSUB Stop_I2C ' Complete TX data ' Load INT1_THS_XL: 10010100, Interrupt LSB threshold bits 7:0 GOSUB Start_Gyr ' Adresss the device SSPBUF = $33 ' Transmit register address WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task SSPBUF = %10010100 ' Transmit the 8bit data to register WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task PIR1.3 = 0 ' Clear interrupt flag GOSUB Stop_I2C ' Complete TX data ' Load INT1_THS_YH: 00100010, Interrupt MSB threshold bits 14:8 GOSUB Start_Gyr ' Adresss the device SSPBUF = $34 ' Transmit register address WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task SSPBUF = %00100010 ' Transmit the 8bit data to register WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task PIR1.3 = 0 ' Clear interrupt flag GOSUB Stop_I2C ' Complete TX data ' Load INT1_THS_YL: 10010100, Interrupt LSB threshold bits 7:0 GOSUB Start_Gyr ' Adresss the device SSPBUF = $35 ' Transmit register address WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task SSPBUF = %10010100 ' Transmit the 8bit data to register WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task PIR1.3 = 0 ' Clear interrupt flag GOSUB Stop_I2C ' Complete TX data ' Load INT1_THS_ZH: 00100010, Interrupt MSB threshold bits 14:8 GOSUB Start_Gyr ' Adresss the device SSPBUF = $36 ' Transmit register address WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task SSPBUF = %00100010 ' Transmit the 8bit data to register WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task PIR1.3 = 0 ' Clear interrupt flag GOSUB Stop_I2C ' Complete TX data ' Load INT1_THS_ZL: 10010100, Interrupt LSB threshold bits 7:0 GOSUB Start_Gyr ' Adresss the device SSPBUF = $37 ' Transmit register address WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task SSPBUF = %10010100 ' Transmit the 8bit data to register WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task PIR1.3 = 0 ' Clear interrupt flag GOSUB Stop_I2C ' Complete TX data '|||||||||||||||| end XYZ Interrupt threshold settings |||||||||||||||||| '////////////////// Duration set value ////////////////////////////////// ' The ODR sets the LSB; 1/190Hz = 5.26ms ' The maximum Duration time is 6 bit or 128, Max = 128 * 5.26ms = 673ms ' The bit value = Duration/5.26ms '/////////////////////////////////////////////////////////////////////// ' Load INT1_Duration: 10000001, Wait enabled, Duration set to 1.3ms GOSUB Start_Gyr ' Adresss the device SSPBUF = $38 ' Transmit register address WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task SSPBUF = %10000000 ' Transmit the 8bit data to register WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task PIR1.3 = 0 ' Clear interrupt flag GOSUB Stop_I2C ' Complete TX data ' Load INT1_CFG: 00101010, OR combo of INT, not Latched, interrupt request ' on measured value HIGHER than preset threshold GOSUB Start_Gyr ' Adresss the device SSPBUF = $30 ' Transmit register address WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task SSPBUF = %00101010 ' Transmit the 8bit data to register WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task PIR1.3 = 0 ' Clear interrupt flag GOSUB Stop_I2C ' Complete TX data ' Load CTRL_REG5: 00011010, Reboot mem Norm, FIFO disabled, HPen enabled, ' Out_SEL = HPF+LPF2, INT1 = HPF+LPF2 GOSUB Start_Gyr ' Adresss the device SSPBUF = $24 ' Transmit register address WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task SSPBUF = %00011010 ' Transmit the 8bit data to register WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task PIR1.3 = 0 ' Clear interrupt flag GOSUB Stop_I2C ' Complete TX data ' Load CTRL_REG1: 00111111, ODR=95Hz, LPF1=12.5Hz, LPF2=50Hz, Norm PWR, ' ZYX axes enabled GOSUB Start_Gyr ' Adresss the device SSPBUF = $20 ' Transmit register address WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task SSPBUF = %00001111 ' Transmit the 8bit data to register WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task PIR1.3 = 0 ' Clear interrupt flag GOSUB Stop_I2C ' Complete TX data RETURN '||||||||||||||||||| end Gyroscope configuration ||||||||||||||||||||||||
I2C Start and Stop routines:Code:'//////////////////// Gyroscope XYZ data reading //////////////////////// ' Recommended way of reading sequential registers ' ' Master Slave Note ' 1. ST Sends Start condition ' 2. SAD+W Sends Slave Address including Write bit ' 3. SAK Sends Acknowledge ' 4. SUB Sends Sub Address (1st register address to read) ' 5. SAK Sends Acknowledge ' 6. SR Sends a Repeated Start condition ' 7. SAD+R Sends Slave Address including Read bit ' 8. SAK Sends Acknowledge ' 9. Data Sends Data ' 10. MAK Sends Acknowledge ' 11. Data Sends Data ' 12. MAK Sends Acknowledge ' 13. Data Sends Data (Process repeated) ' 14. NMAK No Acknowledgement sent after last register read ' 15. SP Sends Stop condition ending Read process ' ' Reading all XYZ registers and loading the array takes 237us worst case. '//////////////////////////////////////////////////////////////////////// Read_G_REG: ' Generate Start condition GOSUB Start_Gyr ' Send first register to read with bit #1 set indicating READ and bit #7 ' set indicating multiple reads SSPBUF = %10101000 ' Register 28h with 7 set = $A8 WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task ' Wait for ACK from device WHILE SSPCON2.6 : WEND ' Wait until device sends an ACK ' Send Repeated Start condition SSPCON2.1 = 1 ' Send Repeated Start condition WHILE SSPCON2.1 = 1: WEND ' Wait until MSSP module finishes task ' Send device address with Read bit set SSPBUF = $D7 ' Transmit device address w/READ bit WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task ' Wait for ACK from device WHILE SSPCON2.6 : WEND ' Wait until device sends an ACK '///////////////////// Read the next 6 registers //////////////////////// ' This portion loops through Read sequence 6 times. The Master sends an ' ACK after each read indicating "send another" so no ACK is sent after ' the 6th data packet, a Stop Condition is sent instead to end the READ. '//////////////////////////////////////////////////////////////////////// FOR e = 6 TO 11 ' Receive the 8 bit data from gyroscope SSPCON2.3 = 1 ' Enable the Receiver to clock in data WHILE !SSPSTAT.0: WEND ' Wait until Buffer Full bit is set XYZ_RAM[e] = SSPBUF ' Load each XYZ_RAM byte in array ' Master sends ACK for first 5 data packets IF e != 11 THEN SSPCON2.4 = 1 ' Initiate Acknowledge sequence WHILE SSPCON2.4 = 1: WEND ' Wait until Acknowledge sequence Idle ENDIF NEXT e ' Send Stop condition to end Read function GOSUB Stop_I2C ' Complete RX data read RETURN '||||||||||||||||||| end Gyroscope XYZ data reading |||||||||||||||||||||
Code:'========================================================================= ' Generate Gyroscope Start condition '========================================================================= Start_Gyr: ' Start condition to the transmit device address SSPCON2.0 = 1 ' Generate Start condition WHILE SSPCON2.0 = 1: WEND ' Wait until MSSP module ready to TX PIR1.3 = 0 ' Clear the Interrupt flag SSPBUF = $D6 ' Transmit address that includes WRITE bit WHILE SSPSTAT.2: WEND ' Wait until MSSP module finishes task RETURN '========================================================================= ' Stop I2C routine '========================================================================= Stop_I2C: SSPCON2.2 = 1 ' Initiate Stop condition WHILE SSPCON2.2: WEND ' Wait until MSSP module finishes task PIR1.3 = 0 ' Clear interrupt flag @ nop ; Had to slow it down or it didn't work! @ Nop ; Only 1 was needed but 1 more won't hurt RETURN
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