Vybrid VF6xx : LWADC crash

[jeremyesquirol]

Hello,

I try to use example of lwadc on MQX 4.0.2 (Timesys) on TWR_VF6XX. I follow the Timesys "How To " for building MQX BSP and PSP.  I'm able to launch mcc-pingpong demo and it works on my board.

However, I need to do some measure using ADC. I found the example "lwadc_twrvf65gs10_m4", It build without error but when I launch it it seems it crashes in  monitor_potentiometer function when calling "_lwadc_get_attribute(...,LWADC_REFERENCE, &reference))" .

I  comment this function, it doesn't crash but the adc's value doesn't change when I moove the potentiometer:

Here is a sample of my code :

input = BSP_ADC_POTENTIOMETER;

_lwadc_init_input(&potentiometer,input);

/* We want to change the default scaling of the potentiometer to return a percent instead of milli-volts.

printf("Rotate potentiometer. Test will run until readings range from  10%% to 90%% \n");

	while(1) { //read ADC value
	_lwadc_read_raw(&potentiometer, &percent);
	printf("potentiometer = %d\n",percent);
	_lwadc_wait_next(&potentiometer);
	}

With this code, i get on my serial :

     potentiometer = 756

     potentiometer = 756

     potentiometer = 756

Do I forgot something?

note : the potentiometer is working fine. I test it with multimeter.

[alejandrolozan1]

Hi,

I wonder if you are initialising the lwadc.

_lwadc_init(&BSP_DEFAULT_LWADC_MODULE);

I do not see the above line in your code.

Best Regards,

Alejandro

[jeremyesquirol]

Hi,

The init of the lwadc is called in the file "init_bsp.c" :

#if BSPCFG_ENABLE_LWADC

    #if BSPCFG_ENABLE_LWADC0

         _lwadc_init(&lwadc0_init);

    #endif

    #if BSPCFG_ENABLE_LWADC1

         _lwadc_init(&lwadc1_init);

    #endif

#endif

Do I need to free the adc module on Linux to use it on MQX ?

Or maybe, I have to change the MQX version ?

[alejandrolozan1]

Hi,

Have you tried the lwad example found at mqx/examples/    folder?

[jeremyesquirol]

Hi Alejandro,

Yes, the first thing I tried was the lwadc example. I built it with no error, launch it from linux console using mqxboot and the program start but block without printing any value.

I've found that it was blocking  when calling _lwadc_get_attribute(...,LWADC_REFERENCE, &reference)) or _lwadc_set_funtion(LWADC_REFERENCE,value).

In the example I was not able to SET or GET the LWADC_REFERENCE parameter. So, my code is the example in which I've removed all _lwadc_set_funtion() calls and i made a read_raw() instead of read()

[alejandrolozan1 · Accepted solution]

Hi Jemery,

I just tested the example but in the latest MQX version, and it is working with no problems.

Could you try with that version?

Regards,

Alejandro

[jeremyesquirol]

Hi Alejandro,

I tested with the latest MQX version (4.1.2) and it works !

But now it's the mcc-pingpong which doesn't work because functions has been modified on the m4 processor with the latest MQX version but not on a5 processor (Linux) but I saw in this post linux libmcc that they working on it.

I except that it will be ready as soon as possible.

Thank you for your help Alejandro.