VREF = 3.3 V instead of 2.5 V

Keil Studio
,
1

Hello,

I am using the P-L496AG-CELL02 board and am creating a program to read the value of ADC1 at pin PC_4. I want the VREF to be 3.3 V and not the internal 2.5 V. I have inserted the necessary solder bridge at R18. However, I get an error when initializing the AnalogIn because of the 3.3 V applied and I cannot adapt the analogin_device.c file.

#if defined(TARGET_DISCO_L496AG)
/* VREF+ is not connected to VDDA by default /
/ Use 2.5V as reference (instead of 3.3V) for internal channels calculation /
__HAL_RCC_SYSCFG_CLK_ENABLE();
HAL_SYSCFG_VREFBUF_VoltageScalingConfig(SYSCFG_VREFBUF_VOLTAGE_SCALE1); / VREF_OUT2 = 2.5 V /
HAL_SYSCFG_VREFBUF_HighImpedanceConfig(SYSCFG_VREFBUF_HIGH_IMPEDANCE_DISABLE);
if (HAL_SYSCFG_EnableVREFBUF() != HAL_OK) {
error(“HAL_SYSCFG_EnableVREFBUF issue\n”);
}
#endif / TARGET_DISCO_L496AG */

I would like to change HAL_SYSCFG_VREFBUF_HighImpedanceConfig(SYSCFG_VREFBUF_HIGH_IMPEDANCE_DISABLE) to HAL_SYSCFG_VREFBUF_HighImpedanceConfig(SYSCFG_VREFBUF_HIGH_IMPEDANCE_ENABLE); and HAL_SYSCFG_EnableVREFBUF() to HAL_SYSCFG_DisableVREFBUF().

Can anyone help me with this problem?

2

Hello,
Your question seems to be hardware dependent and concerns the ST HAL.
We recommend you to get in touch with the ST community.
Thank you.