Why Isn't the CM4 Able to Pull the ESP32's RX Pin Down to 0V?
I kind of have an issue somewhere and I am honestly quite stumped. I designed a board using a Raspberry CM4 and an ESP32S3. The ESP32S3 has USB-PD and is powering the CM4 through it. The ESP32 board has a CP2104 USB/UART-Bridge. Both the CP2104 and Raspberry are connected to the ESP32's UART0.
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For some reason the CM4 isn't able to pull the ESP32's RX all the way down to 0V. Anyone happen to have a clue on what may be going on here?
That's quite literally it. Nothing else.
Hello @Gendos why are you connecting both to the USART0 of the ESP?
"Both the CP2104 and Raspberry are connected to the ESP32's UART0."
Can you explain more on this? What are you trying to do?
I meant to use both the Raspberry to flash the ESP32 as well as the CP2104.
The ESP32's supposed to be used with the Raspberry board I designed, but if you were to use it as standalone, you could program it via USB.
You can program it using the UART pins by pulling the boot pin low and resetting the chip
I know, but that's not my issue.
My issue is: Why does the Raspberry only pull down the ESP32's RX to 1.8V?
@Afuevu May you be able to assist me with this?
I think the CP2104 may be the cause of that, can you disable the CP2104 and check again
I don't believe I can disable the CP2104 without cutting a trace.
Slight oversight on my part. Oops.
you have more than one board? maybe you can cut a trace and try and see
or look for a way to power the board withouth using the USB PD
Doubt - Can we connect branch out multiple uart peripherals to a single pair of uart lines?
Yeah, i will suggest you use 2 pin connectors to disable and enable. You get what i mean?
Something like the yellow connector
