PO hacks

looks like theirs some solder pads on the back of these beauts to wire up a speaker. I’m hoping the push buttons have large enough solder pads so I can wire up an extra set of buttons so you ccan control the device with your feet when busking.

TE posted a picture of a device that accepts these ports. For uploading firmware. I dunno if they will put out anything. As per hacks the only one I can think of is getting the PO synced up with the ios app synkcontrol which would give you wireless midi tempo control of your PO. Seems like it should work.

You can buy elm32 dev kits for something like $30 from Silicon Labs and the software is free.


according to Silabs, the efm32 series doesn’t support jtag so I’m not sure what TE is using or calling JTAG. I imagine it wouldn’t be too hard for the right sort of person to figure out if they were so inclined.

Looking like an emulator called J-Link or something.
Soldering triggers or pads or something to the buttons would be great! I know on the BleepDrum, the buttons just pull the input to ground. If this is the same, you could put some inverters/relays/MOSFETs to do this. This would be great for triggering individual sounds that happen from key presses.

The problem with altering the code would be that unless you can download the code from the device in human readable format (or convert to human readable format), you would be left to completely recode through the JTAG from the ground up. Or you could somehow convince TE to open source the code (can't see that happening).

@GCF Besides that, the EFM32 in the POs may be set to prevent reading the code from the internal flash…

Would be cool if TE released the source code, but I doubt they would. It would be really cool if the OS could be updated via the audio in jack a’la Korg, then allow users to hack at the sounds…

Tech specs of the Gecko used in the PO


@darenager Damn, I shoud’ve asked Jonas (engineer) more about the above details. He did say that the POs can’t be updated and they thought about being able to update through the sync ports, but they just had no time. But it is hackable through the soldering pads on the back.

Sorry I’m not versed in much of the coding aspects.

Does anybody in the forum have an original “Moogfest” PO-12? If yes, would you please post a highres picture of the circuit board so we may start identifying its main components part numbers?

@Kites I wish there was a way just anyone could reprogram these things. It’s not likely TE will work on an update of any kind if only a few people could make use of it. On the other hand if it’s possible to do it through the back of the unit then I’m sure someone will eventually write a custom firmware, given how popular these seem to be.

I don’t know about what I’d want from an update though. There’s probably not much more you can cram into these. One feature I would want is to have some means of triggering notes and parameter changes externally, not necessarily midi. If they weren’t quantized I wouldn’t care as much but I can just record it to tape instead of using the step sequencer.

^loading a different PO OS. For instance ON a sub load the RHythm firmware or the factory?

Yeah you probably could. The LCD wouldn’t work right though. Besides that and the paint I bet they’re all the same hardware.

^ definitely the same, silabs efm32 gecko mcu, and probably a few passives, and a couple of ICs, all of the sound generation and sequencing will be handled by the efm32. If the OS was released you could almost certainly buy the dev kit @KrisM linked to above, and run it on the dev kit - assuming you had the software to decompile/recompile you could edit it.

^ I have ordered that devkit and a PO-12. First thing to do is confirm whether the EFM32 debug mode was locked to protect the original firmware from being read back or not. The fact that the LCD covers all components will make it a pain to find out what is connected to what. I will probably need to beg TE to provide some details on that, at least for the interface pins at the back…

That efm32 chip is classy and really inexpensive.

Are they using the DAC direct to amp? I just love the idea of people at NAMM gushing over 12-bit audio just after hearing the analog stuff.

@anomalous The PO product page on TE site mentions that it uses a “Cirrus logic DAC”. All current selling Cirrus DAC appears to be 24-bit.

Actually, this is something that I believe changed from the “Moogfest” version. That board did not seem to have a DAC, so it was probably using the EFM32 onboard 12-bit one…

Ah, well that’s a different story! I hadn’t noticed that section before. Thanks.

Oh I just realized, I don’t think looking under the screen will help you see the paths. I don’t see much of anything exposed on the surface. Maybe the area under the screen is a different story.

@anomalous Agree about the board hiding the traces… I’m thinking about using a multimeter continuity mode to probe the various pins, but I’m afraid I would have to lift the display somehow, argh!

Well there’s always destructive analysis. :wink: I couldn’t bring myself to do it though. Maybe if someone’s breaks you could grab that and get more invasive.

I don’t think there is much to see. What surface traces exists are painted over. The rest are on the inside of the board(sandwiched) plus its all surface mount except the LCD.