Serial port pins exchange

[coderatchance]

Hello all,

put together the layout and printed the circuit, but somehow I have put the RXD from the uC to the RXD on the transceiver, same for the TXD connection.This is wrong and it should be way around, so I am wondering, if there is anything that can be done within the ATTiny 1616 I am on , for example, is it possible to "internally" change the function of the pins? Not swapping the positions...

On the other hand, if it would be best to printout another, improved layout and print the PCB again. I am limited on budget, so I am also wondering, how much would that increase the costs of making another PCB, around 30 pieces ?

Best.

[hmeijdam]

If you want to use the HardwareSerial features of the MCU, you are bound to the designated TXD and RXD pins. If you use SoftwareSerial you can leave the TXD/RXD pins as general IO pins and e.g. could have PB3 as TX and PB2 as RX. Basically bitbanging the signal yourself to arbitrary pins.

[hmeijdam]

Looking at the TJA1027 datasheet I think you have it right if you have RXD <> RXD.

Or the datasheet has me confused, but it is describing a RXD pin as output.

[coderatchance]

Indeed! Great, that somebody else sees this as well 🙏🏾!This exactly what I have followed, but not sure if it works! For example how would someone go about testing it?Should I be able to see the 0x55 sync or  the break or what ever :) on the osciloskop ? For example I can make the master slave configuration too.Any advice how to proof the connection would be more than welcome 🤗 Best,Sent from my iPhoneOn 22 Dec 2025, at 15:59, Hans ***@***.***> wrote: Looking at the TJA1027 datasheet I think you have it right if you have RXD <> RXD. image.png (view on web) Or the datasheet has me confused, but it is describing a RXD pin as output. image.png (view on web) —Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you authored the thread.Message ID: ***@***.***>