A reverse engineer has documented how Xiaomi’s Mi Band 10 fitness tracker uses a Bestechnic SoC, built a compatible software kit from a leaked SDK for a near-identical chip, and got the GBADoom project running—though display performance remains limited.
He likes to play Doom on devices that were never meant for it. Then he takes a break—by cracking open Xiaomi Mi Band fitness trackers and writing custom firmware.
That hobby is now turning to the Xiaomi Mi Band 10, and the latest target is its BES2700iMP system-on-chip. Internally, the manufacturer Bestechnic reportedly calls that same chip the BEST1503. All of it has been documented in a GitHub project.
The hard part wasn’t discovering what the Mi Band 10 uses. It was figuring out how to talk to it. For this Mi Band 10 SoC, there’s no public SDK available. That “major bummer” briefly stalled the work—until the reverse engineer noticed a workaround.
The BEST1306 (listed as BES2700IHC) is effectively the same SoC, but with a leaked SDK accessible through what appear to be audio-focused development kits. From there, the next step was building an SDK that could work with the BEST1503.
To prove the pieces fit together, Doom was ported to the device, using the GBADoom project as the starting point. The result “mostly works,” but it isn’t a clean run. The display is operating in single-bit SPI mode rather than the quad-SPI mode it should support. and the band’s color depth is limited.
The project also made a stop at Claude for help—burning all the tokens—but it didn’t move things forward. The likely reason is simple: the needed information hasn’t leaked out of Bestechnic yet, and ended up in a training dataset that doesn’t contain the missing details.
There’s one more layer to the story. The Mi Band 9 uses the same SoC, so the expectation is that the reverse-engineered SDK could work for that earlier fitness band too. But it hasn’t been tested yet.
A video walkthrough of the process is embedded here: https://www.youtube.com/watch?v=XdoPEcibQdg
Mi Band 10 BES2700iMP BEST1503 Bestechnic reverse engineering custom firmware GBADoom Doom port leaked SDK quad-SPI single-bit SPI Mi Band 9
So basically someone put Doom on a smartwatch band lol. I don’t get why the screen only does single-bit SPI though.
This is cool but also kinda scary? Like they’re cracking open these bands and changing firmware so easily, what’s stopping someone from messing with health data.
Wait I thought you couldn’t even run apps on a Mi Band? Like they’re saying there’s no public SDK so they just used an audio kit and then magically Doom works… seems fake to me. Also the tokens thing wtf is Claude doing, is that like a robot?
I saw a clip about this and I swear it looked smoother than “mostly works.” Plus Mi Band 9 same chip right? So why not Doom on 9 immediately? Makes me think Xiaomi already knows and just doesn’t care, which is typical. Also I don’t know what quad-SPI is but single-bit sounds bad for everything, not just games.