Nano Every won't replace Nano

I'm trying to replace a Nano with a Nano Every, but the TXD pin seems to not work. The TXD on the Every blinks but sends nothing to the RS-485 board it's connected to.

Any thoughts?

Which RS485 board do you have and how have you wired it to the Nano Every?

How are you determining that your RS485 board isn't receiving the data from the TXD pin?

Despite the name, they are very different boards. This discussion has lots of the details: Nano vs Nano Every - #2 by Juraj

I don't know the manufacturer of the RS485 board. It's from China (of course). The TXD pin from the Every connects to the TXD wire on the RS485. With the Nano connected, the TXD LED on the board will blink when the TXD LED on the Nano blinks. With the Every, its TXD blinks but the RS485 LED doesn't blink. The circuit is on a breadboard. I simply replaced the Nano with the Every. Everything else remains the same. The Nano configuration works, the Every doesn't.

The Tx and Rx pins on the Nano Every are Serial1.
Serial is for the usb serial and is separate.

1 Like

That sounds wrong. When the Nano transmits a byte shouldn't it go to Rx on the RS485 module ?

2 Likes

@ptblake can you provide a drawing/schematic of how you wired the RS485 board to your Nano Every.

The RS485 boards i have don't have a pin labelled TXD. Arduino TXD usually goes to a pin labelled RI, and the Arduino RXD pin usually goes to a pin labelled DO.

Photos of your RS485 board would also help.

Its a little odd, but it is from the instructions, and it works.

Instructions from the manufacture say to connect TXD toTXT and RXD to TXD.
It works fine with the Nano but not with the Every.

Can you upload a photo of your RS485 board or provide a link to where you bought it from?

did you use emulate nano ports options on every for compatibility?

I don't understand. Do you mean that I should use Serial1.print, for example, instead of Serial.print?

The board is from Amazon

Ah, it's an auto switching RS485 board. So you don't need the usual RE & DE signals.

I had a quick look for some more information on that particular board but didn't find any. You need to figure out what the TXD and RXD labels on the board mean. Is the TXD pin where the received RS485 data comes out (i.e. transmitted back to your Nano Every), or is it where the Nano Every transmitted data goes in to the RS485 board.

I would disconnect the wire connected to the Nano Every RXD pin. Next connect the Nano Every TXD pin to the RS485 TXD pin. Make a simple sketch that simply prints a character to the serial port. Observe the TXD LED on the RS485 board.

When you have the Nano Every TXD pin connected right, then I guess that the TXD LED should flash.

Yes.

1 Like

I followed the suggestion from cattledog to use Serial1 instead of Serial. It works great!
The TXD light on the Every doesn't blink but the TXD light on the RS485 does.

Works great. Thanks so much.

That is because that led is tied to Serial, but you now using Serial1.

1 Like

Yes