Compiler/CC3200: ADC example enquiries

Marcus Lee 97

Part Number: CC3200

Tool/software: TI C/C++ Compiler

Hi, I am trying to do the ADC example and would like to receive a voltage reading on pin_58. However, I am unsure of some parts of the codes. If anyone understands, please explain it to me..

	          while(uiIndex < NO_OF_SAMPLES + 4)
	          {
	              if(MAP_ADCFIFOLvlGet(ADC_BASE, uiChannel))
	              {
	                  ulSample = MAP_ADCFIFORead(ADC_BASE, uiChannel);
	                  pulAdcSamples[uiIndex++] = ulSample;
	              }


	          }

	          MAP_ADCChannelDisable(ADC_BASE, uiChannel);

	          uiIndex = 0;


	          while(uiIndex < NO_OF_SAMPLES)
	          {
	              UART_PRINT("\n\rVoltage is %f\n\r",(((float)((pulAdcSamples[4+uiIndex] >> 2 ) & 0x0FFF))*1.4)/4096);
	              uiIndex++;
	          }

I don't get why it is required to loop the uiIndex until NO_OF_SAMPLES + 4 or NO_OF_SAMPLES. For my case, I'd like to just read the voltage once. How should I go about doing it? And how should I change the UART_PRINT for "(((float)((pulAdcSamples[4+uiIndex] >> 2 ) & 0x0FFF))*1.4)/4096" to just print out the voltage on PIN_58?

over 6 years ago

0 Hnz over 6 years ago

Guru 39650 points

Hi,

Please see e2e.ti.com/.../2121154

Jan

0 Marcus Lee 97 over 6 years ago in reply to Hnz

Intellectual 735 points

Ahh, I get it now thanks Jan! Can I also ask, is it possible to make a function run asynchronously?

For example, I would like my program to keep sending out data via TCPsockets every 2 seconds, while it runs the other codes in the program.

0 Hnz over 6 years ago in reply to Marcus Lee 97

Guru 39650 points

Hi,

I am not sure that you asking actually.

For more complex code make sense to use RTOS (TI-RTOS, Free RTOS). Almost all peripheral in CC3200 supports interrupts and DMA. Usage of interrupts (and maybe DMA) is good way how to decrease CPU load and increase performance of your code.

Jan

0 Marcus Lee 97 over 6 years ago in reply to Hnz

Intellectual 735 points

Hi Jan,

What I mean is, for example.

SendData(){
I send data here;
}

PrintsMsg(){
Print Msg;
}

Main(){
PrintsMsg();
SendData();
}

I would like SendData to run every 2 seconds and at the same time, run the PrintsMsg() function. I want these 2 functions to run simultaneously. Is it possible?

In C, I managed to do it through threading. But I'm not sure if CC3200 supports this.

-Marcus

0 Hnz over 6 years ago in reply to Marcus Lee 97

Guru 39650 points

Hi Marcus,

As I say at previous answer this is job for RTOS (real-time operating system). Inside CC3200 SDK you find examples for TI-RTOS and Free RTOS.

Usage RTOS require completely different approach of programming of your code and thinking about their functionality. Good introduction into TI-RTOS you find at this tutorial training.ti.com/ti-rtos-workshop-series
Because CC3200 have only one core of application processor, it is not possible do two things simultaneously. But you can design your code to look like that things are doing simultaneously. And this is enough in real live.

Jan