So our hackathon committee signed off on giving every attendee a programmable badge this year, and aparently I'm the one who has to make that happen. We're sitting at about 1,750 registered people. The board design is done and it works, little screen, d-pad buttons, the whole thing looks great on my desk. Now I'm looking at the calendar and quietly panicking. Flashing one board takes roughly 40 seconds over the USB port, and on top of that I want to run a quick test routine on each one so nobody gets a dead badge at check-in. Even at a minute per board that's way more hours than exist between now and the event. I've seen photos of other conference crews with a whole shelf of boards plugged into powered hubs at once, but I don't know if that actually works for programming or if the hubs just choke when you push that many connections. Has anyone here done a batch run like this? Do I beg the engineering department for bench time, recruit volunteers to sit there flashing for a solid week, or is there some trick I'm completly missing? I'd rather figure this out now than be soldering in a parking lot the night before.
How do I flash 1,750 badges before the hackathon doors open?
Oct 15, 2026
Last reply: 37 seconds ago
4 Replies
First reply
I ran a batch like this for a maker faire a couple years back, about 900 boards, and the shelf-of-hubs thing absolutely works. USB hubs handle it fine as long as they're powered, since each board pulling power over a passive hub is what kills you, not the data side. I split…
Read the full replyI ran a batch like this for a maker faire a couple years back, about 900 boards, and the shelf-of-hubs thing absolutely works. USB hubs handle it fine as long as they're powered, since each board pulling power over a passive hub is what kills you, not the data side. I split mine across three powered hubs into two machines and ran the flash script on all ports at once. Each board took about the same 40 seconds, but ten at a time turned a week of solo flashing into two evenings with a helper swapping boards in and out.
Did a run of conference badges a while back and the flashing part ended up being the easy bit. What ate my time was sorting, my advice is set up a done pile, a fail pile and a not-yet pile before you start, and have your volunteers only touch the swap. I also made the flash script run the test right after programming, so a green screen meant the board was good to box up. That way one person can babysit ten ports without thinking. And flash up a dozen or two extras, you will want spares at check-in when someone's badge acts up.
Gotta push back on the 'each board took about the same 40 seconds' part. When I tried running a dozen at once through hubs, the flashing slowed way down because they were all fighting over the same bus. Boards also re-enumerate when they reboot into the bootloader, and cheap hubs whould drop ports right at that moment. I got better throughput running six at a time than ten, even though it sounds slower on paper. Also worth checking wheather your flash tool can even target multiple devices without grabbing the wrong serial number, that bit me once when two boards came up back to back.
Update: it worked. Grabbed four powered hubs, split the boards across them, and it went way faster than I expected. The reply about bus slowdowns was right though, so I only run four at a time instead of a dozen. Also stole the sorting piles idea with the script testing right after flashing, and my volunteers just swap boards between piles. Done in a weekend, no parking lot soldering for me.
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