blue_ledAug 13, 2025
Finished my USB IR transmitter project. I can now control devices via infrared with my smartphone again (the previous one had an IR transmitter built-in). 🤩
Fully populated (6 IR LEDs, 185mW/sr…1.9W/sr total) it is powerful enough to turn on our solar floodnight from some 10 or 15m away (had hoped for a bit more but still helpful).
Satisfied with how it turned out. Stuck a short piece of transparent filament inside a hole in the case to serve as light guide and heated it with hot air to fuse then. Works very well: barely noticeable when off and unfiltered colours when on.
1/4
#electronics #3DPrinting #DIY
Show threadblue_ledAug 13, 2025
The Android app to control the USB IR transmitter is built using only Open Source parts of the SDK as packaged by Debian. No Google license agreement required.
Kudos to the Debian Maintainers who made this possible! Hope this remains possible in the future. (There's some trouble with newer OpenJDK versions apparently.)
2/4
#Android #OpenSource #Debian
Show threadblue_led
Both SWDIO and IR_OUT only being available on the same pin (and thus SWD breaking once IR_OUT is configured) was more annoying than expected given that I already had a working prototype on breadboard (but using a different package). To add insult to injury, I connected the status LED that I had thrown in as a bonus (and thus not validated on breadboard) to a pin that brought out one of the timers used by IR_OUT so it stopped working at the same time. 🤦‍♀️ Fixed that with a small rework (not shown in the photos).
Lesson learned: bring out UART TX even if it's a tight fit, at least on a test point.
3/4
#STM32 #STM32F042
Aug 13, 2025 at 12:26amWeb
Show threadblue_ledAug 13, 2025
Apropos test points: I've been using 0.6/0.3mm through-hole pads (basically untented vias) spaced some 3mm apart in several projects now. Works well with Rigol and Testec oscilloscope probes (though the ground spring can end up a bit bent when it goes through the board). Not so much with the super-cheap probes that came with one of my USB scopes because their tip is too blunt to fit into the hole. Not really a loss; just need to use the Testec probes next time.
4/4
#TestPoint #Oscilloscope #Probe