The PCBs are ordered. I choose white this time, because I also found white battery holders, and the matrix has a white outside. Panelized two pieces on every PCB, to fill the whole 10x10cm area. There is a small square bit of the PCB added there to be glued under the USB plug, to make it thick enough (2.4mm) for the USB standard. Choose DittyPCBs, because they don't care how many designs you have on a panel.
Today I worked on this design further to shave off dollars from the bill of materials. First realization: I don't actually need to have bi-color LEDs if I'm driving them in software, because I can do shades with PWM — great, now only 8x8 LEDs to charlieplex (9 pins) and single-color LEDs are *much* cheaper. Second realization: if I have single color, I can as well use a ready 8×8 matrix and drive it with 16 pins. Cheaper, less soldering and square pixels. Final realization: coin cell too weak, use 2×AA.
This took one sleepless night. In the end, I didn't charlieplex the whole 8×16 matrix (which would require making a 11×12 matrix and the rearranging it), but instead split it in two, into 9×8 and 8×7 matrices. That uses 17 pins instead of 12, but I have enough if I re-use the debugging/programming pins. It also gives me a better scanning time.
If this works, it's going to be great: apart from the bi-color LEDs and battery, I only have 3 components.
Sketches for a PCB for a hair clip with LEDs. The top pattern will be white silkscreen, the bottom will be gold, the PCB will be red.
The ODROID GO arrived today. So far only tested the emulators, and they kinda work fine. Of course the picture is up-scaled and the sound is annoying, but I have no idea how that compares to the original consoles. Next, I'm going to compile MicroPython for this and see if I can get my #ugame games to work on it.
All hail the hypno-jellyfish!
The PCBs and the LEDs arrived, this evening I will calculate the resistor values and assemble it.
In case you were wondering why I called it "Kubik", here's the robot with its head attached.
And the legs are assembled and attached now. Unfortunately some hot glue is necessary at this stage. Still need to cut the cables and solder them, and center the servos. It's also possible to just plug the servos into male headers, but then I would need to do something with the excess wires, so I decided to just cut them and solder them directly to the PCB for this prototype.
Assembled PCB. I managed to fit almost all parts inside the hole in the battery holder. Some problems with the QFN accelerometer, but after a few tries I soldered it right. Now to prepare the firmware...
The PCBs for the Kubik M0 quadruped spider robot just arrived. Can't wait for the evening to assemble them.
An now also touch input in my video pendant is working, so I can switch between images by touching the upper corners! The loading is still super-slow, but that's fixable.
Got the first image on my video pendant gandget. For now it's just a 16-color BMP, because I had the code for that ready, but ultimately I want to do GIFs (yes, animated).
A simple PCB with a bunch of LEDs, to be used for indicators in breadboard projects.
The #ugame project made me grow a lot in a year in terms of PCB skills. Last night I couldn't sleep, which means I designed another PCB. This time I came back to my old project, Tote a quadruped robot, except this time I designed a PCB that contains everything the robot needs on it, including the MCU and the charging. I fit all parts on the bottom side, squeezed under the battery holder, which means the top of the robot will be free for decorations.