svofskiAfter some fooling around with text on the 7-segs, I'm returning back to the original purpose of these display modules: the calculator. I assembled both OLED and VFD modules on a single breadboard and plugged them into MK-61 emulator.
A curious detail. PT6315 used in the VFD driver here can be powered by 3V3, but for reasons explained earlier I'm powering it with 5V. But that makes it not happy with 3V3 logic signals from the Pi Pico. The solution here is to power it from ~4.7V VSYS rail rather than from 5V VBUS. 3V3 reaches that lowest logic high threshold voltage and it works reliably.
I had a bit of a falling out with Mbed Arduino and switched to Arduino-Pico framework because I thought it doesn't work with SPI1. Later I realised that I messed up pin numbers and the framework probably wasn't a problem. For simplicity I keep 2 displays connected to different SPI busses.
Here's some epic dual screen eggog action:
The plan is to make an universal carrier board that would accept both OLED and VFD modules:
The idea is also to make it usable both as a single-board design, hence the elaborate silkscreen labels for all buttons, and as a sandwich with 3d printed buttons like the IVEE.If you missed it, here's a video about my 7-seg VFD text experiments:
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Ooh, I'm curious when you'll release your code and circuit boards, I would build a replica of MK-61 immediately. This was the calculator that I used in my "polytechnic" school. Nostalgia.
Unfortunately, I lost mine.
I ordered one 1-2 weeks ago, from eBucht. I hope it comes soon.
But I would like to recreate it, unfortunately I'm not as talented as you.
BR Ivaylo
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Hi @ivaylo mitev ! The code is here: https://github.com/svofski/calculator-maybe. Currently it only uses input from the terminal, but the output works both for OLED and vacuum displays.
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Thank you very much for that, I have already ordered all the components from Aliexpress. I still have to order a pair of tactile switches and diodes and I'll try to install them all in an old MK-61 housing. Of course I have to do a bit of programming.
Большое спасибо, Ивайло.
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@ivaylo mitev you're welcome ;) I'm really curious to see how it works out for you, let me know.
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Hello,
i tested it today and it works very well so far. I waited a long time for the Pico-Pi, the board arrived 3 days ago. I've never used "Platformio" before, but it worked. And I also rewrote a bit of the code. I have a German keyboard and at the beginning I didn't really understand how it works with the terminal ;-) .
Link to YouTube: https://youtu.be/KDB5GdNbXI8
Kind regards, Ivaylo
P.S.: If I find the time, I'll try to build the keyboard. And I want to expand it a bit. e.g.: Fast mode, a menu, battery display and of course saving and reading programs.
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@ivaylo mitev thanks for sharing! looks really good, I'm so happy that it works for you.
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