Reddit:Electronics

I have to test all sorts of strange things at work. They all require some sort of oddball connection. Every time I need to make something odd connect this is where I start looking.

So my dad who passed back in 09 was, back in his day, big into older electronics, he had this stash of unused tubes back when they adopted me in 83. They're dirty, but all unused. I don't even know where to start with getting rid of them.

It’s not the finish product. I used copper pours instead of wide traces for my power supplies. For the screen shot I deleted the GND. Done in KiCad 7.

The first joule thief i made.

No luck on turning this hfsstc without ociloscope. Have been working on it for 6 months

Total overkill, but I had a "raw" LCD sitting around in my parts bin and finally got around to learn how to use it, so I thought a clock and thermometer project was in order. When I started this a week ago, I honestly didn't know much about how LCDs worked, and definitely did NOT know that AC was needed to make a proper circuit. After wiring up a couple of test circuits, I jumped full in.

The logic is controlled with the Seeeduino Xios (lower left), and the LCD is driven with the AY0438 driver chip (obviously the big IC you see wired with the ratsnest of yellow wiring. Time/temp is handled by the DS3231 module (next to the Seeeduino, no backup battery yet installed).

The other components to the right of the switches is to control a backlight (represented right now with the yellow LED). Simply a 555 timer in monostable mode. Press the blue button and you get about 8 seconds of light. A proper backlight is on order.

Slide switches from left to right: temp/time selection, 12/24 hour selection, F/C for the temperature.

The momentary switches are to set the time: hold down the white button, and green/red to adjust down/up the time.

I coded the Seeduino using C++ in Platform IO. I'm using 2 external libraries: One to read the real-time clock, and the other to drive the AY0438. The latter (https://github.com/supercrab/arduino-seven-segment) was interesting in that you need to define your "template" for your display. Since LCDs come in different flavors, you have to tell it whether yours has decimal points and/or colon. This one does (although my picture doesn't show either).

The time setting routing was pretty interesting to code: First, if someone held down the red/green button, I wanted the time to change very quickly, but if they only clicked it once, I wanted the time to change by only 1 minute.

The way it worked was to loop through the routine as long as the white button is held down. Then the logic essentially checked if a red or green button was pressed, and if so, was this the 2nd consecutive time through the loop that it was detected. If it was the first time, then only change the time by 1 minute, with a long delay (500ms) after detection, allowing the user time to release the button. If it was not the first time, then the button is determined to be being held down, and there's only a 20ms delay after incrementing/decrementing the time. That way you can quickly change the time when setting.

I used all 10 I/Os on the Seeeduino, so if I add anything else, I'll have to think about next steps (perhaps multi-purpose roles for the push buttons depending on what mode it's in).

Next step will be to draw this up in some Cad and route a board. I usually make the prototypes at home, but with all the pin connections to the LCD, I'm not sure how feasible that will be until I route it.

Also not shown here is the battery supply. Using one 3.7v LIPO with a dedicated charging module (HW-373). Circuit draws ~20ma without the backlight. Probably not the most efficient thing around for what it does, but pretty happy with it.

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https://preview.redd.it/7smmgz9lozjc1.png?width=1353&format=png&auto=webp&s=14419e7f2a2e4f072df2d46db68bfd699e0828ec

my first custom contraption that is powered by a Lithium ion battery from a broken solar powered power bank, a board from a simple fan in a toy gas mask, and a led/ resistor indicator. I learned everything i know so far from electroboom. other than that Im new to all of this (ignore the soulder points they’re temporary) any feedback or suggestions appreciated