SPI failure in case of modifications to unrelared code segment

[Jawad]

Hi everyone,

I am using nrf52832 with SDK version 11.0 for an IoT application. I am communicating with Atmel ATWINC 1500 module through SPI in order to connect to Wifi. My code was working fine until I added few new lines of code unrelated to SPI. Now when I run the project on Nordic hardware I get following SPI read errors.

(APP)(ERR)[spi_data_read][385][nmi spi]: Failed data response read...(00) (APP)(ERR)[spi_read_reg][625][nmi spi]: Failed data read...

I know that this error occurs when there is some issue with pin assignment for SPI interface but I have verified all the pin assignments. The stranger thing is that the project starts working fine if I comment out any part of the project totally unrelated with SPI. Following are the results when I compile the project using Eclipse.

'C:/Program Files (x86)/GNU Tools ARM Embedded/5.4 2016q3/bin/arm-none-eabi-size' _build/nrf52832_xxaa.out text data bss dec hex filename 56312 1436 37904 95652 175a4 _build/nrf52832_xxaa.out

It might be a memory issue or some other issue. I have tried debugging it but failed so any leads or suggestion about where the problem might be or how to debug such an issue will be highly appreciated. My Make file and start up file is attached.

arm_startup_nrf52.s Makefile

[bjorn-spockeli]

Hi Jawad, could you post the "unrelated" code that causes the SPI communication to fail?

[Jawad]

Thanks for the comment Bjorn. Below are few such lines of code. They are there for the recording of signals received on gpio pins and those pins are completely different from SPI pins.

	//if transmit interrupt has triggered- toggle pins and reset timer
	if(bus_driver_pins_toggle_flag_volatile == true){
		//reset the flag which has been set in the ISR
		bus_driver_pins_toggle_flag_volatile = false;
		SEGGER_RTT_WriteString(0,"noooooooooooooooooooooooooooooooooooooooooooooooooooo\n\r\n\r\n\r\n\r\n\r\n\r");

		vBus_Pin_Toggle_Handler(); // Uses the hard coded pulse times
		//vBus_Pin_Toggle_Handler_Recorded(); // Uses the real measured pulse times
	}

	//if comparator interrupt has triggered - do time measurement
	if(bus_driver_comparator_flag_volatile == true){

		vBus_Pulse_Time_Measurment_Handler();
	}

	//if time out is detected this means the package has been received.
	if(bus_driver_time_out_flag_volatile == true){
		bus_driver_time_out_flag_volatile = false;
		vDisable_Bell_Signal_Reception();
		SEGGER_RTT_WriteString(0,"Bus package received\n\r");
		u32_bell_detected_flag = u32_Check_Bus_Package();
	}

Also here is another part of code, with same implications,controlling LEDs through pins unrelated to SPI

		   if ((led_delay_value != 0xFFFFFFFF) & (led_delay_value > 0))
				{
					led_delay_value --;
				}
				status_led_main(calling_argument_for_status_led_main);

[Jawad]

Hi Bjorn, Please see my response below

[bjorn-spockeli]

I am assuming that you're initializing the GPIO pins somewhere in the code. Could you comment out all code associated with these pins except the initialization? Does the SPI function properly then?

[Jawad]

Hi Bjorn, I have tried with what you said and then SPI works but the issue is that the part of code I am commenting out to make SPI work does not have anything to do with the pins of SPI. Instead there are a lot of pointers and arrays are present in that part so I was wondering if it is a memory issue. Do you have any suggestion about debugging such an issue?

Thanks a lot so far