How to use analogue pins (not ADC) to read voltage?

[sal92]

hi all,

I am using STM32F733xx and i want to read the Vout i will be monitoring is between 1-5v, to read that i have used analogue pins PG13, PH3 ,PH2,PG14, PE2,PE3, PE6, PE4,PE5,PF1,PF0,PF2

I already have the PCB so i cant change the design can anyone suggest any solution to this?

Looking for some firmware based solution to this problem.

Thanks in advance,

Regards,

Sal

[Andrew Neil]

Welcome to the forum.

For best results, please see: How to write your question to maximize your chances to find a solution.

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@sal92 wrote:

i have used analogue pins PG13, PH3 ,PH2,PG14, PE2,PE3, PE6, PE4,PE5,PF1,PF0,PF2

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None of those pins has any analogue function:

PG13 TRACED0, LPTIM1_OUT,USART6_CTS, FMC_A24,EVENTOUT
PH3  QUADSPI_BK2_IO1,SAI2_MCK_B, FMC_SDNE0,EVENTOUT
PH2  LPTIM1_IN2, QUADSPI_BK2_IO0, SAI2_SCK_B, FMC_SDCKE0, EVENTOUT
PG14 TRACED1, LPTIM1_ETR,USART6_TX,QUADSPI_BK2_IO3, FMC_A25,EVENTOUT
PE2  TRACECLK, SPI4_SCK, SAI1_MCLK_A, QUADSPI_BK1_IO2, FMC_A23, EVENTOUT
PE3  TRACED0, SAI1_SD_B, FMC_A19, EVENTOUT
PE6  TRACED3, TIM1_BKIN2,TIM9_CH2, SPI4_MOSI,SAI1_SD_A, SAI2_MCK_B,FMC_A22, EVENTOUT
PE4  TRACED1, SPI4_NSS,SAI1_FS_A, FMC_A20,EVENTOUT 
PE5  TRACED2, TIM9_CH1,SPI4_MISO, SAI1_SCK_A,FMC_A21, EVENTOUT 
PF1  I2C2_SCL, FMC_A1, EVENTOUT
PF0  I2C2_SDA, FMC_A0, EVENTOUT
PF2  I2C2_SMBA, FMC_A2, EVENTOUT

Please show your schematic - that would be easier to follow.

An ADC is the only way you're going to directly read an analogue voltage as a digital value.

Otherwise, you're going to have to "synthesise" an ADC; eg, use a DAC to generate a "reference", and a comparator to compare.

Whatever you do, it's going to need hardware changes...

[TDK]

Even if they were wired to the correct pins, the ADC isn't going to be able to measure 5 V.

[Billy OWEN]

Hi @sal92 

This post has been escalated to the ST Online Support Team for additional assistance.  We'll contact you directly.

Regards,

Billy

[sal92 · Accepted solution]

Thanks everyone i ended up changing the pin outs and modified the hardware.

Also for the voltage level my input is up to 5v which IC i should use in between in order to change the voltage level but to get the accurate voltage and current reading?

[Andrew Neil]

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@sal92 wrote:

Thanks everyone i ended up changing the pin outs and modified the hardware.

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That's good - please mark the solution:

https://community.st.com/t5/community-guidelines/help-others-to-solve-their-issues/ta-p/575256

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@sal92 wrote:

Also for the voltage level my input is up to 5v which IC i should use in between in order to change the voltage level but to get the accurate voltage and current reading?

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That's a separate question - please start a new thread for that.