Licensing: Tiva™ TM4C123BH6ZRB Microcontroller with CCSv5 IDE

Thanks a lot,  I am now able to debug my code with the XDS100v2 emulator.

Now I am currently testing all the hardware on my development board with TIVA processor(TM4C123BH6ZRBI). I am stuck in testing SPI interface with ADS1218. Can anyone provide me the code for testing ADS1218 hardware say simple flash read/write. I don't know the initialisation steps of this device. I know datasheet provides these, still I would be grateful if someone can provide me the code ASAP. I just need to verify if ADS1218 is correctly interface with SPI by verifying the data read/write through SPI.

BTW ADS1218 is interfaced on SPI2.

Regards,

Mritunjai

Hi,

Can anyone provide me the code for testing ADS1218 hardware say simple flash read/write. I don't know the initialisation steps of this device.

Aren't the SPI examples in Tivaware helping you out?

Regards,

Gautam

I need SPI example for ADS1218 device which is not there in Tivaware example. I may need to write full or minimal slave driver for ADS1218 device in order to test its functionality. Thats why I need the minimal code that can test my slave device ADS1218 and if possible for M25P40(4 Mbit Flash) also.

Regards,

Mritunjai

I need SPI example for ADS1218 device which is not there in Tivaware example.

Sorry, you won't get a direct implementation for the above devices. You'll have to modify the example spi codes wrt to the slave devices by referring their datasheets.

Regards,

Gautam

Hi,

I am trying to test ADS1218 which is interfaced to SPI. Actually what I am trying to test initially is that I am writing to 16 registers of ADS1218 with some values and reading back those values. I am using SPI peirpheral ROM library.

 I can see that I am able to correctly write the value to the registers on the oscilloscope on MOSI line. But while reading the value gives me unpredictable values. I have pasted my code as below:

//Write register

void ADS1218WriteRegister(int StartAddress, int NumRegs, unsigned * pData)
{
uint32_t readDummy, adcTxData[16];
//pData = adcData;

// assert CS to start transfer
ADS1218AssertCS(0);
int ulLoop;

//
// Send the instruction byte and receive a dummy byte to pace the
// transaction.
//
SSIDataPut(SSI2_BASE, ADS1218_CMD_WREG | (StartAddress & 0x0f)); //Write Register(command)
SSIDataGet(SSI2_BASE, &readDummy);

// send the command argument
SSIDataPut(SSI2_BASE, NumRegs-1); //count
SSIDataGet(SSI2_BASE, &readDummy);

// pause according to the data sheet
//delay_us(10);

// send the data bytes
//
// Now send the data to the device.
//
for(ulLoop = 0; ulLoop < NumRegs; ulLoop++)
{
adcTxData[ulLoop] = (*pData);
SSIDataPut(SSI2_BASE, (*pData++)); //data bytes
//SSIDataPut(SSI2_BASE, adcData[ulLoop]); //data bytes
SSIDataGet(SSI2_BASE, &readDummy);
}

ADS1218AssertCS(1); //Chip select high
}

//Read registers

void ADS1218ReadRegister(int StartAddress, int NumRegs, unsigned * pData)
{
uint32_t readDummy, adcrxData[16];
int ulLoop;

// assert CS to start transfer
ADS1218AssertCS(0);

SSIDataPut(SSI2_BASE, ADS1218_CMD_RREG | (StartAddress & 0x0f)); //Read ADC Register(command)
SSIDataGet(SSI2_BASE, &readDummy);

// send the command argument
SSIDataPut(SSI2_BASE, NumRegs-1); //count
SSIDataGet(SSI2_BASE, &readDummy);

for(ulLoop = 0 ; ulLoop < NumRegs ; ulLoop++)
{
*pData++ = 0;
adcrxData[ulLoop] = 0;
}

// pause according to the data sheet
//delay_us(10);

// get the register content
for (ulLoop=0; ulLoop< NumRegs; ulLoop++)
{
SSIDataPut(SSI2_BASE, 0xFF);
SSIDataGet(SSI2_BASE, pData);
adcrxData[ulLoop-1] = *pData;
pData++;
}

// de-assert CS
ADS1218AssertCS(0);
}

// In main() function

main()

{//main starts

//
// Set the clocking to run directly from the external crystal/oscillator.
// configure clock speed @ 16 MHz
//
SysCtlClockSet(SYSCTL_SYSDIV_4 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN | SYSCTL_XTAL_8MHZ);

....

.....

//

// The SSI2 peripheral must be enabled for use.
//
SysCtlPeripheralEnable(SYSCTL_PERIPH_SSI2);

//
// For this example SSI2 is used with PortB[7:4].
// GPIO port B needs to be enabled so these pins can be used.
//
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);

//
// Configure the pin muxing for SSI2 functions on port B4, B5, B6, and B7.
//
GPIOPinConfigure(GPIO_PB4_SSI2CLK);
//GPIOPinConfigure(GPIO_PB5_SSI2FSS); // to be configured as GPIO not as SSI function
GPIOPinConfigure(GPIO_PB6_SSI2RX);
GPIOPinConfigure(GPIO_PB7_SSI2TX);

//
// The SS line is configured as GPIO since the board has 3 devices connected to
// SSI2 and each uses a separate CS.
//
GPIOPinTypeGPIOOutput(GPIO_PORTB_BASE, GPIO_PIN_5);
GPIOPinTypeGPIOOutput(GPIO_PORTQ_BASE, GPIO_PIN_3);

ADS1218AssertCS(1); // assert CS high
M25P40AssertCS(1); // assert CS high

//
// Configure the GPIO settings for the SSI pins. This function also gives
// control of these pins to the SSI hardware. Consult the data sheet to
// see which functions are allocated per pin.
// The pins are assigned as follows:
// PB7 - SSI2Tx
// PB6 - SSI2Rx
// PB5 - SSI2Fss(configured as GPIO)
// PB4 - SSI2CLK
//
GPIOPinTypeSSI(GPIO_PORTB_BASE, GPIO_PIN_7 | GPIO_PIN_6 | GPIO_PIN_4);

SSIConfigSetExpClk(SSI2_BASE, SysCtlClockGet(), SSI_FRF_MOTO_MODE_3,
SSI_MODE_MASTER, SysCtlClockGet()/8, 8);

//
// Enable the SSI2 module.
//
SSIEnable(SSI2_BASE);

....

....

ads1218_txdata[0] = 0x04; //SETUP - ID ID ID SPEED REFEN REFHI BUFEN BITORDER
ads1218_txdata[1] = 0X01; //MUX PSEL3 PSEL2 PSEL1 PSEL0 NSEL3 NSEL2 NSEL1 NSEL0
ads1218_txdata[2] = 0X00; //ACR
ads1218_txdata[3] = 0X00; //IDAC1
ads1218_txdata[4] = 0X00; //IDAC2
ads1218_txdata[5] = 0X00; //ODAC
ads1218_txdata[6] = 0X00; //DIO
ads1218_txdata[7] = 0X00; //DIR
ads1218_txdata[8] = 0X80; //DEC0
ads1218_txdata[9] = 0X07; //M/DEC1
ads1218_txdata[10] = 0X00; //OCR0
ads1218_txdata[11] = 0X00; //OCR1
ads1218_txdata[12] = 0X00; //OCR2
ads1218_txdata[13] = 0X24; //FSR0
ads1218_txdata[14] = 0X90; //FSR1
ads1218_txdata[15] = 0X67; //FSR2

ADS1218WriteRegister(ADS1218_SETUP_REGISTER, 0x10, ads1218_txdata);

for(ulLoop = 0 ; ulLoop < 16 ; ulLoop++)
{
ads1218_rxdata[ulLoop] = 0;
}
ADS1218ReadRegister(ADS1218_SETUP_REGISTER, 0x10, ads1218_rxdata);

....

...

}//end main

I was suspecting that there must be some timing issue but currently I am stepping through the code using debugger, still not able to read values of register. Can you please point out where I am doing wrong.

And also can you guide in case I need to do some more initialisation in order to start writing and reading the ADS1218 registers. Please guide as I have been struggling for last 2 days to get it work.

Quick response will be highly appreciated.

Regards,

Mritunjai 

In case anyone has working code for ADS1218 SPI interface using peripheral library, kindly provide me the code so that I can test this device thorouglhy.

Regards,

Mritunjai 

Hi,

I am still not able to read the ADS1218 register, In first look it seems to be timing issue. Has anyone done it before ie. succesfully talking to ADS1218 interfaced through SPI. I need simple code that simply writes to the ADS1218 registers and read back the values of the same with all the timings/delay taken into consideration as per datasheet.

Anyone from TI guys please help, as I am stuck to this issue for 1 week. You can see my implementation above of this thread.

Also my delay for microsecond not working, it hangs my code.

// Delay for given number of microseconds(uS)

void delay_us(int us) {

    ROM_SysCtlDelay( (ROM_SysCtlClockGet()/(3*1000000))*us ) ; 

}

delay_us(4);       //this call hangs my code

Regards,

Mritunjai