SHS3321 Firmware rollback

Hi All,
Finally got my hands on an V1.5 (the one with fitted diodes) SHS3321 that works with a NeXT Implant.
Unfortunately the v1.5 unit its self has been damaged, but! I dumped the firmware with a PICkit 3 and flashed it to my original SHS3321 V1.7, and volla!! a door lock that reads my hand. A 30 second write up and the firmware is Here


Great job! Hopefully this helps some people with the newer version of the lock.


oh man… can this be posted as a step by step style instructable?


Looks like PICkit 3’s are hard to get - they’re now out of production.

I daresay we could adapt this to a Raspberry pi - but I’m not buying a SHS3321 just for that and I have nowhere to set it up just yet.

It actually makes me wonder if we could write custom firmware for this.

1 Like

Yea, I’ll take some photos and screen shots over the week end and update the git wiki


This is my first ever poke of a PIC platform as an excuse to procrastinate on my thesis so I have no idea if/how another ICSP platform might interact. You probably don’t need a PICKit3/4 to flash the new firmware. I’ve added some links to cheap ones from Ebay and Ali, that’s all the one I used is.

As for custom FW, probably if you spent the time tracing the PCB and / or de-compiled the OEM FW. I’ll add the v1.7 hex with my EEPROM data removed to the git repo this evening so that anyone wanting to hack at that has some more data points.


Really, we’d only be looking at this and modifying the validation runtime.

1 Like

Hi, I recently bought a Samsung 3321 and I’m going to try this out to make it compatible with my xSIID. Going to buy the parts from Ebay USA and Molex. Will update when I’ve got anything worth noting. Thanks for posting this OP!


That would be cool, unless @TamablePumpkin has started making one

Not yet, my Thesis was due on the 4th and I give a presentation on it soon, feel free to make pull request’s to that git repository, or the git wiki and ill get to them when I can

1 Like

I thought I was going to get the PicKit today but since it had USPS shipping it’s probably going to be delayed for a long time… I ordered this and the keyboard wedge device from Dangerous Things with USPS shipping before I realized about the massive delays :tired_face:

Hopefully neither will be too long and I’ll still get to attempt the firmware rollback before the end of January which is when my SHS 3321 is no longer able to be returned to Amazon.

1 Like

Can anyone help me with this? @TamablePumpkin or @Pilgrimsmaster. I’ve got the PicKit 3, the molex connector, and the board of the SHS3321 sitting in front of me, and MPLAB on my computer. How do I… connect these things??? I have no idea what the PicKit is for nor what the parts it came with are used for. I have the Molex connector attached to the SHS3321 but I have no idea how to connect that to the PicKit or the other thing that the PicKit came with. The instructions on the github page are not such that I can understand what I’m doing. Please and thank you!!!

1 Like

Ok, so you don’t need the other thing which came with the PICKit (it’s for programming bare DIP chips)

Its pretty much connect the Molex pin 1 to PICKit pin 1 (with pin 1 shown by the white arrows). Do you have a picture of the Molex connected to the SHS board (I can’t easily find a pic online :joy: )?

Thanks for your response. I’ve got the SHS3321 with teh Molex in there. The Molex connector is far too small to easily fit anywhere in a plug on the Pickit, as far as I can tell.

1 Like

I get the feeling I’m going to have to perform a minor soldering job?

1 Like

Yep, so I believe you’ll need to use small M-M jumper cables / solid core wires or cut the connect off the other end of the Molex connector to connect it to the PICKit unfortunately

Probably yeah

Alright. I was able to find a pdf manual for the PICkit and it does seem that there are some adapters available which would be nice to have for this use. So, before I irreparabley begin modifying these cables, would it be fine to just cut off one end of the Molex cable, and solder it onto the rainbow connector which fits easily in the PICkit? Will the voltage travel okay thru here, or anything like that??

1 Like

Personally, I’d just use solid core hookup wire for the moment to connect from the Molex connector to the PICKit - it looks like this:

Or you can get spools of it. Happen to have any?

Otherwise, yeah you could solder onto the rainbow cable. Just make sure you connect the right wires, and don’t get any shorts between them.

I don’t have anything like that here at home, as far as I can tell. I think I’m just going to go ahead and (carefully) perform the soldering job here in a minute so I can figure out if the firmware rollback is possible. I can get more cables in the future. Thanks for the advice!

Good luck!