Sometimes, you know where the data you need is stored, you just don’t have a way to access it. In this case, [GetHypoxic] needed to rip data off an eMMC chip, salvaged out of a camera. With no desire to wait for an adapter to show up, it was time to bust out the bodge!
Once removed from the PCB, bodge wires were attached to the ball-grid array contacts on the bottom of the chip. Incredibly fine soldering was the order of the day to get these hooked up to the tiny pads, and we count 11 or 12 bodge wires in total. 1.8 volts was manually supplied to the eMMC chip, and it was directly wired up to the contacts of a built-in card reader out of an old laptop for reading.
Despite the rats-nest look of it all, and the yellow polyimide tape holding it together, [GetHypoxic] reported that it mounted successfully and got the job done. We’ve seen similar hacks before, too, wiring eMMC chips up to SD card adapters. It might look messy, but hey – it sure beats waiting for shipping!
Thinking to myself, wouldn’t it be nice if someone sold a blank pcb, one end having the chip layout and the other made to fit into an SD card slot.
That would be nice… but pinouts of eMMC chips aren’t uniform… in any way, at all.
They are standardized.. it’s just that there are too many versions and variants of the standard :)
Sure, but you could still design a breakout board, to make the jumper wires easier to solder.
There are 3 or so common packages and then 3 more less common ones. After that there are mostly proprietary one off packages.
Adapters to standard SD cards can be found on AliExpress for next to nothing.
Just search for “emmc adapter” on Aliexpress.
Oh! I could look into it! In the meantime, I have a MicroSD PCB in my repo that would be a decent base for this: https://github.com/CRImier/MyKiCad/tree/master/Third-party/usd-adapter . Aside from different eMMC pinouts, I’m pretty sure someone could design a PCB set that works!
I would recommend a USB SD flash reader if you do this kind of work (eg short when soldering the reballed emmc). I damaged the SD card slot in a laptop by connecting an SDIO wifi chip to it for driver development. Probably the power draw was too high as an LDO/load switch broke (fortunately trivial to replace, used external psu after that, USB reader is not an option when using SDIO.)
“bust out the bodge!”
My slogan for the week — or maybe the rest of the year.
It’s what my mom said shortly before my partition…
Do SD and eMMC use the same protocol?