Issues with Arduino and multiple printers

I have two printers both using Arduino Mega 2560 boards, one has a board about a year older than the other. When i try and connect to the newer board my laptop doesnt recognize it. If i install the latest Arduino drivers it will connect and works fine. But then it doesnt recognize the older Mega board using the upgraded driver. I would like to be able to use the same laptop to move from one printer to the other but i cant do that right now.

So what is the easiest way to resolve this issue, is this a common problem?

On most of the Arduino Mega 2560 boards (clones can vary) they have a chip that talks to the USB (usually in the corner near the socket). This chip is actually a tiny Arduino in itself, so it's programmable.

My guess is that the programming on one of the chips (they're usually ATMega 8u2's) differs to that of the other, which is why the older one doesn't work with the newer drivers.

Easiest/fastest way is to buy two new Arduino's from the same place. They're most likely to have the same code on the 8u2's. This isn't always a cheap option (depends on how you value your time and how cheap you get them, shipping, etc).

The other way is to get access to an ICSP for Arduino (such as the Adafruit USBTinyISP) and reprogram the 8u2's on the boards with the same version of code. If you've got a hackerspace nearby, they may have one if you don't or can't afford one. If they do have one, Hopefully someone there can help you through the process, as it's not a really simple thing to do. It's not too hard, but can be daunting if you've not done it before.

If those boards are in any way different regarding how the 8u2's are hooked up, you haven't got a hope. That is fairly unlikely though, as almost all the clones are just that - clones - direct copies of the boards. They don't change anything as then it's more work for them (eg: getting code written that works with the new arrangement).

I would visually inspect the boards. If they look identical, then you should be able to reprogram them. If not, I'd look at either getting two identical new boards, or taking a chance that you can buy one that matches one of the two boards you already have.

Hope this helps.

That sounds a little over my head. I was hoping for something easy. If i were to buy new matching boards i probably would be more inclined to look into upgrading to running from a flash card.

Thanks.

Fair enough too.

That said, if you're a member of a local hackerspace, or there is one nearby, they may be able to help you with the Arduino side. You don't even need to take the printers with you to the hackerspace, just the two Arduino Mega boards. As long as they're running the same code (the arduino sketch, eg: Marlin, Sprinter, etc) then the issue will show up as soon as they're plugged in.

Good luck!

You don't need a hardware programmer to reprogram the 8U2/16U2: they have a bootloader. (It's also possible to use the second Arduino as a programmer, but note that the connection diagrams there are for reprogramming the main microcontroller, not the U2.)

However, I don't know if the firmware is compatible across hardware versions.