Hi folks, Like many here, I spliced a trinket onto a CR2032 battery holder to lash up an external loader dongle. It works, but I decided to whip up a board with SAMD on top and CR2032 holder on bottom to make things a bit easier. Boards arrived today and I am programming the pick and place to build some up. If it all works out, I'll check the code into github and offer them to folks that are interested. My intention is to make an external dongle, but I added big D+, D- pads to make an internal install easier as well. Of course, an internal install won't need the CR2032 and some other components, which the board is set up to do as well. I'll give updates as the project makes progress. EDIT - The project is done! I'll use this space to give updates. Keep reading the whole thread to enjoy the technical details of the development. Batch 2 is in stock! Now with multiloader code (thanks mattytrog). This code stores all 3 loaders (hekate, reinx, and sxos), and allows you to change on the fly without reflashing. To use - plug in normally and power on. While searching for Tegra, the device will show 1, 2, or 3 quick blinks to signify which payload is active. To change payload, Ground D1 and hold - The blinking cycle will increment through 1, 2, and 3 blinks. Let go when you desired loader is selected. To store your selection to flash, Ground D0 momentarily. The Activity LED will light for ~1 second to signify your selection being stored. Get the multiloader UF2 below What is it? It's a small SAMD21 board with an onboard CR2032 battery holder. It can be used to send fusee gelee payloads Why did you build it? I wanted a board that was instantly-on, and that I could reprogram with open source tools How do I get one? You can PM me or go searching on Tindie. I will sell them here on the site once my account is approved for that, shouldn't be long How big is it? 24 x 25mm Can it fit inside my console? Yes, with the battery clip and other tall stuff omitted. I made the USB pads big for easy soldering. PM me, it's easy to set up the build to skip those components. What do I need to get injecting? A CR2032 battery, a USB micro b to C cable, and an RCM jig. All can be found on ebay or Amazon for a low cost, but I am working on getting both included Firmware Source Code: (Compile and flash with Arduino, forked from sam-fusee-launcher) (you probably want this one if you want to hack on stuff) https://github.com/electronrancher/sam-fusee-launcher Multiloader Source Code: (Compile and flash with Arduino, forked from the V1.0 firmware just above) https://github.com/electronrancher/SAMD_Fusee_Multiloader Bootloader Source Code: (Compile with GCC and flash with SWD, forked from uf2-samdx1) (You probably don't ever need to touch the bootloader, so you may not care about this one) https://github.com/electronrancher/uf2-samdx1 Pre-Compiled Firmware: Available below. To flash, plug into USB and double click reset. A flash drive will open on PC called FIRMWARE. Take the 3 files from one of the zips and drop them onto the flash drive. Programming takes place as the files are written, so as soon as the transfer completes you can eject and go launching.