askelectronics

I have a 12v 6.67A power supply with a male co-axial plug (with centre pin) that’s 7.4mm OD and 5.08mm ID. The metal tube is 12.5mm long....

I want to connect five OV2640 cameras via FPC to an ESP32 on a custom PCB. Is this generally possible and does the ESP32 have enough power for this or do I need an ESP32 for each camera? The frames per second are not so important as the cameras will be used as QR code scanners. Which components allow to run so many cameras with...

Hi all! I recently purchased some push-lights for my kitchen from my hardware store, and I stupidly didn’t read the package that said that they shut off after 30 mins. This is super inconvenient in my dark kitchen, and I can’t return them. I figured I might as well tinker with them, and any help would be greatly appreciated....

Right to the point: On a BPI-R3, should connecting the UART debug pins directly to the appropriate pins on a DB9 USB serial adapter (rx->tx, tx->rx, gnd->gnd) work? Because I’m just getting a garbled mess in my serial console. I’ve tried all different baud rates. I’m using a high quality serial adapter (Keyspan Tripp...

Hey folks, I have a Mackie 802-VLZ4 mixer which does this narsty pop when you turn it on; I’m pretty sure it’s what killed one of the woofers in my monitors. It has been put out of service and I will either harvest its many through-hole organs or else fix it....

Hi!...

I've wondered this occasionally over the years, but never got it working....

I recently bought a thinkpad T470 for a good deal, and it turns out that it was a good deal because the BIOS is locked with an admin password so I can't install an OS, or change any BIOS settings....

Since MOSFETs have a gate capacitance you’d want to limit the inrush of current from the output of a microcontroller to prevent it from getting damaged prematurely. That’s what gate resistors are usually good for....

My Google-fu has completely failed me. I’ve got an RGB addressable led curtain. It has 20 strings of 20 LEDs in a square arrangement. I initially assumed it had a wire feeding led data back up, to go to the next drop. On checking however, they are T jointed....

Questions:...

Is there a way to figure out my LED board and fix it myself? I got this LED light which works perfectly but the issue is the usb charger port on the left is not working for whatever reason. There are two ports one micro for charging the led and one usb for outlet charging. Is there a way to switch the charging to the usb port?...

https://discuss.tchncs.de/pictrs/image/e2575314-be01-4a3f-bab2-cc75811b3ce8.png...

If I wanted to make a USB desk fan from a spare CPU fan (input: 12V, 0.15A), could I just solder a resistor to the positive lead of the USB wire? I plan on getting an adjustable voltage booster, but I was curious if this was possible. I think I would need a 13 ohm resistor for USB 3.0.

Working on a joystick. Seems like any protocol I use to read from peripherals is going to be bottlenecked by having just one input. My microcontroller might have multiple ADCs, but there’s just one processor stepping through them. Same for spi, or i2c, or uart. There’s really only ever one sensor reporting back its data at a...

Hi, my cousin has an Xbox Series S, and anytime he would move it the fan would make some pretty freaky noises....

I’m trying to use an LIS2MDL ic with an Arduino nano on a custom PCB designed in KiCad. I tried the Arduino example compass script for the ic and it didn’t work. It just prints “Magnetometer Test” and nothing else happens

As the title says, I’m looking for a Linux/macOS-compatible EPROM programmer. I’d like to be able to program parallel (E)EPROMs in the 27xxx range. The newer XGecu programmers seem to not be compatible with Linux/macOS, and the selection of TL866(II) clones is too overwhelming for me to be able to choose one....

I lost my electric fence tester, probably the pigs ate it. But I opened it once to resolder the earth wire and found it’s really just a voltage divider with resistors and leds, so I can probably rebuild with stuff I have. What resistor values though? 2k to 10k V run through the fence. If any of you good people have a diagram,...

I’ve been looking for a simple low-voltage cutoff circuit for a 12v SLA battery, but many of the ones I find have reviews saying that the protection circuit itself drains the battery slowly as well. Is this just inherent in the design, where it has to draw a little to measure the voltage, or are there low-voltage cutoffs that...

Hello! Someone suggested this "If the MOSFET is put into diode connection mode (connect the gate to the drain), you can force a small current (I recommend 1 uA–10 uA; 1 mA would probably be OK; 100 mA would result in significant power dissipation and could influence the results) and record Vds (which is equal to Vgs in this...

The recent post on using a lamp in series to limit potential fault currents has had me thinking about using them as above. Has anyone done this? I can see advantages, cost for one - wirewound resistors can be expensive. Visual indication of a varying load. Make it "short-circuit proof"..

It happens rarely, but I will notice either my phone or the charger getting pretty toasty randomly. What could be causing this?

I work on equipment that runs off 3 phase 208V but it uses uses a transformer to drop it down to 120V for most of the controls. On this equipment I noticed that there are two fuses on the lines exclusively feeding the 208V side of the transformer and a fuse directly off of the hot side on the 120V side of the transformer....

Hello altogether, I guess everybody has some USB-C cables lying around, but wonder if it’s 3A, 5A, 3.0, TB… Anybody able to recomment a device able to determine that? Maybe also something that can be combined with a load tester.