EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: Rishles69@ on January 04, 2025, 07:12:37 am
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Can i use GPS modules on UART0 gpios 43 and 44 of esp32-s3? In official datasheet, it says I could use it as a normal gpio. So my question is, can I actually connect a gps module to those pins? If possible, what measures should I take in order to use it for my project? Can anyone conform this?
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By default, the MCU’s boot messages are output to UART0 (and to the native USB). That could cause issues with the GPS (you haven’t stated what kind of interface the GPS uses so impossible to say for sure). You can change this with an efuse setting so it only outputs to the native USB.
But unless you are short on pins, use something else for GPS and at most put something non-critical (like status LEDs or whatever) on the UART0 pins.
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Well thanks for the help. By the way, I'm using ATGM336h gps module which uses the UART interface to communicate. What will happen if I disconnect esp32-s3's uart 0 pins from the gps module while uploading the code? Or can I use 2 push buttons on those pins with pull ups or pull downs?
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The problem has nothing to do with programming, but with the fact that by default, you get a boot message every time the MCU starts up, including every time you turn the device on. Just because you don’t have a computer connected with which to read those messages doesn’t mean they aren’t being written.
The easiest thing is to just use different pins if you have them. As I said, if you have “dumb” things you are connecting, like switches or LEDs, put those on the UART0 pins and put the GPS on unencumbered pins.
If you absolutely have no free pins and no way to reassign other pins, then disable the boot message with the efuse setting, and then program using the native USB rather than UART.