I’ve had succes finding them at small arduino-y hobby electronics stores, rather than the big electronics warehouses.
But you’re right, I should update the design with a more modern part…
Hey Guys. 
After a little bit of finishing other modules, i got around testing my ERG and i have the sad theory, that the TLC5940 Chips are faulty, all four of them.
I asked Tim about the Code because i couldn’t get it to work at first. But now i think it might also be these ICs that prevent anything from working. When i turn on the Module with the Arduino, it lights up for a moment, then goes dark and that was it.
I’m turning it on without the Arduino plugged in, and…i don’t know, shouldn’t all of the LEDs light up?
They do not. So i guess the ICs are not working properly and therefore prevent the whole circuit from going anywhere. Unfortunately, i didn’t even make a picture of it.
So, if anybody has an idea if my theories could be right, please please tell me.
Besides that, if these cheap chip suppliers are just unreliable because the TLC5940 is “obsolete” and they don’t give a “you know what”…
I saw these SOIC to DIP Adapters, which i think fit perfectly here: PA-SOD3SM18-28 - Logical Systems Stock available. The distributor Micro-Semiconductor.com offer the best price with new original products.
But there aren’t many sources. I need four. So, is there any chance to get them under 20 + Shipping Dollars? I didn’t even talk about the SOIC TLC5940, did i? 
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Have you tried running it without the TLC5940s seated? The LED display works completely independently from the I/O, so you should be able to clock it and get output even without the LEDs. (though it will obviously be a bit hard to see what you’re doing). If you don’t get anything even without the LED drivers, there’s another problem…
As for getting the ICs… they indeed seem to be getting very scarce now. I’ve spotted one local supplier who claims to have stock. If so, I’ll consider buying them up for all remaining PCB sets. But then again shipping them overseas in not so convenient. I guess going HTSSOP (TLC5940PWP) is your best bet. I see those in stock for ~3 euros /each.
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I’m pretty sure i tried that. I have to try again to be sure. But it bothered me that not all LEDs were working without any input. And if it’s an independent circuit it reassures me that the ICs are broken.
If i have anything substantial, i come back to it.
Honestly, if the ics are fake, there’s no telling what those leds might do. Who knows what’s in that package…
A local supplier claims to have 50 Dip TLC5940s on stock. For anyone who needs them, I can test them and ship them. Cheers!
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Wow, that would be great! I had no luck in finding an adapter yet…well, i had no luck with health either, had Covid for the first time from Dec 24 onward and no “motivation” in finding anything for a few days there.
If you have an interesting module lying around to pack into the envelope as well, maybe i can buy that too, might be nice for shipping costs. Anyways, shoot me a message.
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What the what!!! Must have!
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Do you have any full sets of pcb’s along with those unobtanium IC’s for sale?
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Well I received a batch of them from a seemingly reputable store here in NL… which turned out to be fakes too. So, until I find the time to redesign the module with different parts (which realistically will take a while), I’ve resolved the issue with a HTSSOP-DIP adapter:
The HTSSOP TLC5940PWP is still in production and readily available. The adapters are with JLCPCB now, they’ll be available in a few weeks with the PCB sets!
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Tim,
The adapters have the TLC5940PWP soldered to them as part of the PCB sets?
-Fumu / Esopus
JLC didn’t have them in stock, so I couldn’t get them pick and placed. HTSSOP isn’t too tiny, it should be doable by hand…
Tim,
With my tiny-lead solder skills being suspect and the quest to get a process for making my own panels which itself seems to be planned to happen later than other projects I’ll pick up your redesign.
-Fumu / Esopus
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Hi Tim, i like to buy this pcb and panel , how can i contact you?
Gr, Raymond
Clock input not working. I used 2 5.1v diodes and 100k to ground, 470ohms just as the schematic shows. When i hook up my Korg SQ1 and use the gate or sync out, i see no activity on the oled display. I do see activity when connecting the clock input directly to 5v, but only when i tap it. So it needs higher current? Can someone give me some advice? Thanks in advance
I think you’re in the wrong thread, there’s no oled here
There is on the one in Dud’s link to which they were responding.
Assuming you’re talking about this module 800円で作るユークリッドリズムシーケンサー-モジュラーシンセ自作｜HAGIWO/ハギヲ, current has nothing to do with it; it’s looking for a voltage level. On an Arduino, a low logic level is below 1.5 V, high level is above 3 V, and behavior is undefined for 1.5 to 3 V. If your SQ1 gate output is below 3 V it might not work. But here KORG SQ-1 OWNER'S MANUAL Pdf Download | ManualsLib it says sync out level is 5 V and gate out level is 10 V. Those should be plenty to trigger. So there must be a hardware problem somewhere, either in the SQ-1 or in the module, or a problem with the module’s firmware. Might need to use a scope to track it down.
Hi
Ok, i’m sorry.
But i found the problem. My clock in jack was not properly grounded.
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