I put up some better pictures of the solder points for the beat repeat/stutter button on my PO12 arcade button mod.
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I bet a talented circuit bender could mod a PO to hell and back.
The second gen has the same layout. Mine cracked and stopped working, then I removed the screen and it started to work again!
The second gen has the same layout. Mine cracked and stopped working, then I removed the screen and it started to work again!
@<a href=“https://www.operator-1.com/index.php?p=/profile/2213/Chantecleer” class=“Username” style=“margin: 0px; padding: 0px; border: 0px; outline: 0px; font-weight: bold; font-size: 15px; font-family: “lucida grande”, “Lucida Sans Unicode”, tahoma, sans-serif; vertical-align: baseline; text-decoration: none; color: rgb(1, 115, 198); line-height: 22.1px; background-color: rgb(252, 252, 255);”>Chantecleer<span style=“color: rgb(37, 38, 30); font-family: “lucida grande”, “Lucida Sans Unicode”, tahoma, sans-serif; font-size: 13px; line-height: 22.1px; background-color: rgb(252, 252, 255);”> Cool mate 
Good to know…
Please send @punji-sensei hi-res pictures !
Thanks @Chantecleer. That confirms the HW is identical for the first and second PO series (except for the displays). I was not sure about that, I thought TE could be using a MCU version with more flash memory.
@<a href=“https://www.operator-1.com/index.php?p=/profile/97/punji” class=“Username” style=“margin: 0px; padding: 0px; border: 0px; outline: 0px; font-weight: bold; font-size: 15px; font-family: “lucida grande”, “Lucida Sans Unicode”, tahoma, sans-serif; vertical-align: baseline; text-decoration: none; color: rgb(66, 157, 168); background-color: rgb(252, 252, 255);”>punji<span style=“color: rgb(37, 38, 30); font-family: “lucida grande”, “Lucida Sans Unicode”, tahoma, sans-serif; font-size: 13px; background-color: rgb(252, 252, 255);”>
<span style=“color: rgb(37, 38, 30); font-family: “lucida grande”, “Lucida Sans Unicode”, tahoma, sans-serif; font-size: 13px; background-color: rgb(252, 252, 255);”>What was your pogo pin size/layout for connecting to the back? I’m looking to possibly use pogo pins for a case design and was wondering about the size, as they would work great for a no solder setup. Thanks for all your exploring on the matter!
I never did a “production” version for the pogo pins connector, just some hacking:
I think a small “U” shaped plastic piece could be printed for that purpose. The small pogo board would be attached to it and the slot in the middle would slide into the PO board, latching to the connectors.
There are many pogo pin sizes/heights. The spacing between the pins is 0.1 inches. You can see each pin function at hackingthepo.weebly.com.
Note that in your case only the power pins would be useful, so I’m not sure that justifies all the trouble…
- We're (ThinkMakeRepeat) & (JNFX Pedals) are working on a batch of new power supply kits for the Pocket Operators series. They come with a cable for 3, but a kit of 4 with chain-able plugs is definitely possible.You plug a USB micro cable into one end and the other end has a 2.1mm power jack. The POs get a solder and glue-on connector with another 2.1mm jack to plug into the USB power supply.Here's a link to JNFX's kit on Reverb.com to check out, it's out of stock but we're working on a new batch now…We'll be fulfilling from Los Angeles now, so the shipping cost should be much cheaper going forward.
Also, for larger strings of POs we're working on a tiny version of the kit that uses a micro-jst connector instead of the 2.1mm jack on the PO side.
I just unmounted the display of my PO-28. It has the same EFM32, but with 256 kB flash. See here for details:
http://www.eevblog.com/forum/reviews/teenage-engineering-po-28-robot-pocket-operator/
That is interesting, I did not suspect they had upgraded the MCU.
Now, what I’m really curious about is the metal series. They must have fit some extra RAM memory chip in there…
Hi @punji, thank you for your great work. The Pocket Operator has two more sets of pads:
- Two oval pads from the front side which are connected together when the metal stand is used. I can understand that these pads are useful from mechanical point of view (so that the stand does not scratch soldermask) but I also see vias near the pads. This could be used to detect position of the stand but it does not seem to correspond to any feature described in operation manuals
- Two circular pads from the rear side just “below” the battery pack (not the speaker ones; can be seen here: https://i.imgur.com/nWYMwg3.jpg)
Do you know what these are for? Also, why do you think they exposed the PLED test point? It looks like they are actually using that pin for factory programming and/or development: https://www.instagram.com/p/yI2VyVuz-X/
Ok, I took my multimeter and the circular pads are connected to the oval ones on my PO-33 (it is also obvious from the nearby vias). Isn’t that suspicious? There is some kind of switch which does not seem to be used for any known feature and the switch is also exposed from the rear side where they connect their programming/test jig.
As far as I recall, there were no MCU ports that could have been connected to those pads, i.e., all MCU ports were accounted for and mapped as indicated in the hackingthepo page. I tested the continuity between those pads when the stand is down and it seems to require quite a lot of force, so it does not seem very useful.
Regarding the PLED test point, it is not required for flashing the PO. Maybe they use it only for mecanical stability between the programming jig and the attached PO.
Are you doing any hacking with PO? The last I messed with that was just before the PO-33 got released. I connected a serial flash to the PO and did some testing with that. My idea was to add storage for sampling. I’m still curious to know how TE did that, but it seems nobody tried to remove the display from a busted PO-33…
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Hi, thank you. On my unit the contact between the two oval pads is nice when the stand is down but I only have it shortly.
True, they might have populated the PLED pogo pin on their jig for mechanical stability (also, it looks like there is nothing more than a standard debug cable which connects directly to the devkit). Why do you think the PLED testpoint is present on the PCB? It kind of duplicates the SWCLK testpoint (the only difference is that there is the 47R resistor between one of them and the MCU’s SWCLK pin).
I’m not doing any hacking (originally I wanted to inject notes using the debug interface but as it is locked, there is no way to do that), I only want to understand all the test points
Ok, maybe they have the circular/oval test points for some end of line tests to check if the stand has been mounted correctly (because mounting it probably involves manual work and it can be mounted with a wrong orientation or not mounted at all).
Yeah, that PLED test point is very strange. Anyway, there is no way to interface with the POs using the pads, that was a huge wasted oportunity for the mod scene , they could have added some simple MIDI like serial protocol there. The PO is a very un-hackable synth, unfortunately.
I totally agree. At least they could have exposed an UART which would accept characters corresponding to individual buttons (way easier to implement than MIDI).
Maybe the PLED test point is a way to check if a correct MPN is populated on the board by measuring current flowing to the LED?
Another weird thing is the double arrow mark. The marking is quite clear for voltage and ground but how does the arrow correspond to our LED?