alphanumeric & 3d printing
25 Jul 2021builds: Lander Module
tags: HT16K33 thermal-printer
Recent efforts have gone into getting the 14-segment alphanumeric display working. I first tried it with d2r2’s translation of the Adafruit library into Golang, but that proved a little frustrating. I then pivoted to periph.io’s experiment, and that worked much better. I do have to wrap it in some logic for a few reasons:
- out of the box, it panics in certain situations related to the decimal
- I will need a single interface that ends up controlling multiple ht16k33 devices (as in a 6- or 8-digit display)
- I will likely need to implement scrolling text
- I may or may not need the interface to control a whole line of nearby displays (as in the case where there are two 6-digit timers, but sometimes they work together to scroll a long string) But I got the test (ht16k33Test) to work! Here are some next steps I’m tracking:
- incorporate a segmented display into the console, and the modeTest. Have the display print different things in different modes.
- try using periph/conn/gpio instead of warthog618/gpiod
- begin playing with the I2C multiplexer board
- begin playing with the oled screen
- order a 24-bar graph (also based on ht16k33), and play with that
- begin playing with the analog joystick
- flash the Butterstick with normal-ass keys and write a listener specifically for those keys
- experiment with the textured Prusa print plate?
- Measure the keyboard cutout, 3dp a cover with known rectangle cutouts and screw-holes.
- Print a switchplate for the butterstick
- Make cuts for other panels, determine how to screw panels on
- Go to the first build crew meeting
- establish communication with someone who can help with the power circuit
- re-establish who is writing the narrative
As of the last meeting (7/22 with Dr Professor), we had a sketch of the final layout of touchpoints (see notes/layout_1.png). It did not include the bar-graph module though…
~ ~ later that day ~ ~
First print of a panel was a huge success! I did the thermal printer. I made the cuts to the vent port, and now the TI-99/4A is ruined! (for any other purpose).
The spacing of the vents is such that I think I’ll need to use #3 screws. It also happens that that’s the size that should fasten the printer to the plate! So far I’d been imagining using my stock of #8 screws, but it’ll be good to have options.
Case in point: I’m printing test plates now for the keyboard backer and keyboard switchplate, and the first test uses #8 for both, but I can already tell that no. 3 might be more fitting to fasten the switchplate to the eventual front plate.
Did some more thinking about the 24-bar graph idea. I think I’ll pick up a few to play with, but I don’t think there’s room for them on the console.