LPC MicrocontrollersのトピックRe: Errors in "periph_adc" example for LPC11U68

Errors in "periph_adc" example for LPC11U68

mjuggles — Mon, 20 Nov 2017 17:54:55 GMT

Using theLPCXpresso11U68 Evaluation Board, the "periph_adc" example has a warning and an invalid configuration.

The code is from: lpcopen_3_01_lpcxpresso_lpcxpresso_11e68

The warning is in Chip_ADC_StartCalibration() because the variable save_ADC_CTRL is set but not used. Removing the declaration and assignment resolves the warning.

The invalid configuration is in the IOCON setup:

/* ADC input 8 is on PIO0_12 mapped to FUNC2 */
Chip_IOCON_PinMuxSet(LPC_IOCON, 0, 12, (IOCON_FUNC3 | IOCON_MODE_INACT | IOCON_ADMODE_EN));

The code sets the pin to Function 3 which is for the CT32B1 peripheral. The comment is correct, Function 2 is for ADC_8. Oddly enough, the ADC actually works with both Function 2 and 3, but Function 2 is specified in the User's Manual Rev. 1.8.

Re: Errors in "periph_adc" example for LPC11U68

kerryzhou — Wed, 22 Nov 2017 08:14:07 GMT

Hi Mark Johnson,

Thank you for your feedback.

1. Chip_ADC_StartCalibration warining

void Chip_ADC_StartCalibration(LPC_ADC_T *pADC)
{
   uint32_t save_ADC_CTRL;

   save_ADC_CTRL = pADC->CTRL;
   Chip_ADC_SetClockRate(LPC_ADC, ADC_CALIBRATE_RATE);

   pADC->CTRL = (pADC->CTRL | ADC_CR_CALMODEBIT) & ~ADC_CR_LPWRMODEBIT;
}

Yes, the save_ADC_CTRL is really not used in the code, the following code use pADC->CTRL directly, but it doesn't matter, it won't influence the code function.

2. PIO0_12 mapped problem.

I have checked it on my side, you are right, it is really wrong, it should be IOCON_FUNC2 instead of IOCON_FUNC3.

I already report this problem to our according department, any reply will let you know.

Thanks for your report.

Have a great day,
Kerry

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Re: Errors in "periph_adc" example for LPC11U68

kerryzhou — Thu, 30 Nov 2017 08:53:09 GMT

Hi Mark Johnson,

Thanks a lot for your patience.

I have got the reply from our according department, it is the lpcopen code bug, it should be IOCON_FUNC2 instead of IOCON_FUNC3. This bug has been report.

Have a great day,
Kerry