A new switch on the Arduino board.

If my soldering skills weren’t so terrible, I would probably do this myself and put together an arduino from a kit but …

It would probably be really handy if there were a simple DPST switch on the board to disconnect the headers for pins 0 and 1. That way you could switch off to load a sketch, switch on to use the pins in the circuit, or switch off again to debug.

There’s no reason you can’t use the pins in a sketch as normal IO or for the hardware UART, so I’m not sure what you’re asking for.

Unless you mean the short time at powerup when the bootloader is in control.

Well digital pins 0 [I think] does have problems because it is connected to the USB - Serial chip. I think that’s what you want to disconnect for use?

/me

You can use them in a sketch, but if you’ve got them wired up to a circuit, then you have to disconnect in order to upload a new sketch. It’s not such a big deal if it’s just a jumper wire going to a breadboard, but I can imagine if you have a shield or two stacked on top it could be a nuisance pulling it apart every time you want to update. A switch to disconnect the headers from pins 0 & 1 while leaving the usb/serial intact for reprogramming would be useful, that way you could just switch-disconnect the pins when uploading, reconnect them when done, and then reset while leaving the project assembled. It could help too if you have a circuit using 0 & 1 but need to debug (I’m a noob and it’s already happened to me), you could switch those pins off and be able to use the serial monitor, again without having to disconnect everything.

You could just disconnect 0, but as 0 & 1 are both used for serial, and you could disconnect them both with a single dpst switch, it seems safer to do both.

You can use them in a sketch, but if you’ve got them wired up to a circuit, then you have to disconnect in order to upload a new sketch.

This is pretty strongly dependent on the circuit that they are wired up into. Though some sort of switch would be easier from a “I don’t want to have to analyze it” point of view. Unfortunately, switches tend to be large and cumbersome compared to the size of the arduino board itself…

Unfortunately, switches tend to be large and cumbersome compared to the size of the arduino board itself

Yeah, but then again, so are full sized usb connectors ::slight_smile:

It wouldnt necessarily have to be a switch, jumpers could do the job too as long as they’re near the edge of the board.

You could use a third pin to control a micro relay or logic chip that goes between your external circuit and pins 0 and 1. Implement some sort of ‘normally-open-like’ behavior and only allow them to work once the Arduino has gotten to a known state.