Pinout for the NUCLEO-F767ZI to use the HX711

[Apal]

Hello,

I’m currently working on integrating the HX711 load cell amplifier with my NUCLEO-F767ZI development board. However, I’m having some difficulty determining which GPIO pins to use for the SCK (clock) and DT (data) lines.

As I’m relatively new to working with STM32 boards, I’m unsure how to properly select the appropriate GPIO pins for this setup. I came across a video demonstrating the HX711 with an STM32F103C8T6, where PB9 was used for SCK (output) and PB8 for DT (input). However, since I’m using a different board, I’m not sure if the same pins apply.

Additionally, someone mentioned that on certain STM32 boards, PA pins are typically analog and PD pins are used for digital signals. I’m not sure if this is relevant to the NUCLEO-F767ZI, but since the HX711 sends digital signals, I was considering using PD pins. I would appreciate any guidance on which pins are best suited for this application, or if there are any specific considerations I should keep in mind.

Thank you in advance for your help.

[Andrew Neil]

The first thing to determine is what is the actual function of those SCK (clock) and DT (data) lines.

They don't appear to be any standard interface (not SPI; not I2C; not UART) - so, presumably, you're just going to bit-bang them?

So any GPIOs will do for that.

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@Apal wrote:

someone mentioned that on certain STM32 boards, PA pins are typically analog and PD pins are used for digital signals.

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You can check that in the chip datasheet, and the board's User Manual and/or schematics.

In general, any Px pin can be used as a digital GPIO, but only some also have analogue functions:  so, if you want the analogue functions, you need to make sure you use correct pins - but if you only want digital, you have much freer choice.

Similarly if you want specific functions like SPI,I2C, UART, etc.

This is not really different from any other microcontroller ranges.

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@Apal wrote:

any specific considerations I should keep in mind.

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Do you need 5V tolerance?

That also restricts your choices.

[MasterT]

Usually, those adc driven by bit-banging , so you select GPIO pins making short-wiring to peripheral.

Download schematic - located on ST.com of nucleo-f767 product page, under CAD tab selector.

Get datasheet for uCPU, there is a table of all GPIO with alternative functions. 

And Reference manual, with details on programming GPIO.