Boot Loop after installing FX Mod

I recently got an Arduboy and a FX module (hardware only). After verifying that the Arduboy itself worked properly, I went about installing the mod. At first, the FX activator showed two X’s (I think I was too careful when installing it) so I went over it again with my iron and got two checkmarks. I selected the Flash Mod chip option, and got a message saying that it was verified. I then tried to flash the bootloader. Upon rebooting, I see the lower half of the Arduboy logo at the top of the screen for a split second before it reboots and the same thing happens around five seconds later. I can’t upload the flash image because I get an error saying that the bootloader doesn’t support it.

Where do I go from here? I could go over my soldering again, but I’m not sure if the flashing was truly successful and if it would start working again when I get my soldering right, or if I would need to somehow make it return to the FX activator and go from there. I just don’t want to mess with it TOO much, since I know the connections are fragile in there. Thanks in advance.

Edit: Here’s footage of the boot loop:

Did you load the flash cart yet?

@Mr.Blinky Any idea what would cause this?

I’m pretty sure this is because the flash cart is not loaded, but it is supposed to show a [USB] symbol, not attempt to boot into… ??

If you successfully burned the bootloader try this next step:

I installed the hardware mod to the best of my ability, then followed the directions from the github ( and the flasher utility in order. The boot loop began happening after I completed step 4. In the utility, which was installing the bootloader from the Arduboy. I tried moving to step 5, but I got an error saying that my bootloader doesn’t support writing to flash. Not sure if the bootloader didn’t flash properly, if it’s not connected well enough to run now that it is flashed, or probably both.

Edit: I found a YouTube video of a successful FX mod install. I see that the arduboy should show a USB icon after the bootloader is installed but before writing the flash image, but I never saw the icon. Just a black screen that leads to the partial Arduboy boot logo as seen in my video.

You should be able to try the bootloading process again and CAREFULLY hold the reset button for 2 seconds.

I turned it on again and (carefully!) held down the reset button. It didn’t seem to do anything, except for when I pressed it while the logo was on screen. This caused the logo to get partially distorted, but otherwise the result was the same. I’m guessing that my soldering isn’t making a good enough connection somewhere. I just don’t know if I’ll be able to tell when I get it right or not if something got corrupted when I tried flashing the first time.

I think this might be the result of a poor connection the reset line of the mod chip. You might try getting the reset line to work. It you were able to load software into the mod chip, and it is verified, then holding down reset button for 2 seconds should start the bootloading process.

It sounds like that maybe the chip was attempting this, which is what that garbage on the screen you saw, but isn’t fully resetting the chip during the programming step.

There was another user who had a similar problem but was able to eventually get it working.

Have you tried uploading the activator sketch again? I’m guessing that doesn’t work?

TLDR: Got it working!

I had already tried uploading the sketch again, to no avail. So I opened it up and specifically reflowed the reset contact. That didn’t seem to help, so I reflowed each contact, briefly stabbing down through each blob in an attempt to reach the pads below. After turning on the unit on one last time, the screen did a happy dance followed by the USB boot screen! I was able to flash the image without incident, and I’m now enjoying a fully functional Arduboy FX. It was a little tricky to get working, but worth it in the end for the reduced price versus a premodded unit.

Couple things I don’t quite understand yet. To add new games to the flash chip, they need to be compiled into one image and flashed using the FX Activator python program, right? Is someone planning to maintain the image and update it when new/updated games are released? Also, what happens if someone tries to load an individual sketch the old way?

Thanks for the help and advice. I came pretty late to the Arduboy party, but I’m glad to finally be here.

Good you’ve resolved the issue.

Just to Elaborate. The mod chip was not able to program the Arduboy bootloader because of the poor reset connection.

Once the modchip is instructed to flash the bootloader and is unsuccesful in updating Arduboy’s bootloader. It will try updating the bootloader again the next time you power on.

You saw part of the Arduboy logo because the modchip was not able to update anything. As soon as the modchip tries the update again you see the screen go black.



I’ll almost certainly put out some new revisions and publish them, but I haven’t figured out like a “plan” for this or know how long I would commit to it. The good news is anyone can do it.

My hope is actually many people develop their own carts and distribute them kind of like mix tapes so people can be Arduboy DJ’s.

@mr.blinky has some hopes to work on the tools and @tuxinator2009 had been working on making an easy tool as well.

Ultimately, I’d like to be able to host something similar to what is on the FXtest github and allow it to compile the cart online so you can click and drag to make your own cart and download a bin, also link people to your collection. But that will take some time, I’m focusing on doing shipping right now.

Still works as normal except you might find the auto-reset works a little different because of the new bootloader. If you upload via the USB it is the sketch that is stored on the 32u4, so the next time you start it up, you can load it back up just by pressing A or B button, but if you load another sketch then you can’t get it back without putting it on via USB again.

In some ways, the party is just getting started. For 6 years already, doing pretty good. Everyone knows that it’s cooler to be fashionably late. :cool: