I’m currently building a project that requires a USART interface, and I was hoping to use my Arduino Pro Micro to provide that, since the Atmega32U4 does support USART, but apparently the USART clock pin is being used for the Tx LED instead. Is there any way to use USART without the XCK1 pin or am I going to have to build a board from scratch for this one? UART isn’t sufficient, it does need to be syncronous.
Disconnect the LED then wire the USART clock pin to the serial connector.
Yeah, I don’t feel like ripping the LED off for a single prototype project. The final product will be built on a custom PCB anyway, I was just hoping to design the prototype around an existing board… is there any way to handle the USART clock in software, assigning the signal to a GPIO?
Why can’t you connect the pin (and LED & resistor) to the device you need it for ? I’d think the 32U4 would have no problem sinking the LED current plus whatever the current comes from the device at the end of the link. Or are you looking to have the external device provide the clock ? IOW how is the presence of the LED different from having a pullup ?
Yes, if you have a fully software USART so that the clock and data timing are synchronized.is there any way to handle the USART clock in software, assigning the signal to a GPIO?
This code is not that difficult and is called ‘bit banged serial’. Lots of examples exist, just add a clock output.