BQ79731-Q1: When V1_GPIO1 ~ V15GPIO15 pins have been configured as "0b001 = As ADC only input (ratiometric).", the register always reads as 0xFFFF.

John Lu

Part Number: BQ79731-Q1

Tool/software:

Hello,

We are using using the TI sample software of "bq79731_sample_code-BQ79731_Branch_031822", to run on our setup of "TMS570LC43 + BQ79600 + BQ79731 eval boards" setup. However, all GPIO HI/LO registers continue to read as 0xFFFF, as if the GPIO pins are never enabled as ADC Inputs.

Later on, we added these lines of code in the TI sample software:

WriteReg(0, GPIO_CONF1, 0x09, 1, WriteType);

WriteReg(0, GPIO_CONF2, 0x09, 1, WriteType);

WriteReg(0, GPIO_CONF3, 0x09, 1, WriteType);

WriteReg(0, GPIO_CONF4, 0x09, 1, WriteType);

WriteReg(0, GPIO_CONF5, 0x09, 1, WriteType);

WriteReg(0, GPIO_CONF6, 0x01, 1, WriteType);

WriteReg(0, GPIO_CONF7, 0x09, 1, WriteType);

WriteReg(0, GPIO_CONF8, 0x09, 1, WriteType);

Still, all GPIO1~15 registers continue to read 0xFFFF.

Please advise and help. Thank you.

John

9 months ago

0 John Du 9 months ago

TI__Intellectual 2315 points

Hi John,

Please check if the set GPIO configurations are written before setting ADC to continuous mode. Turning ADC on is done through register ADC_CTRL2 (0x311). One can write 0x05 to enable the ADC in continuous mode.

Best Regards,

John

0 John Lu 9 months ago in reply to John Du

Intellectual 275 points

Hi John,

Per what you described above, it is indeed working now. Thank you!

John

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BQ79731-Q1: When V1_GPIO1 ~ V15GPIO15 pins have been configured as "0b001 = As ADC only input (ratiometric).", the register always reads as 0xFFFF.