Reddit:Electronics

The custom pcb for my LoRa radio just arrived, sorry for the burnt mouse pad, i apparently like to solder over it😢

Found in an Apple IIe power supply. Never seen this before, but it seems to work! I didn't know you could solder to aluminum like that.

It's basically two DF Players, one plays a metronome track (prog rock, so not constant time nor signature) and the second a backing track for the songs that have it. Each output is stereo, and has a signal led with an LM393 comparator, with the set point done by the ESP32 DAC.

Next I'll implement the MIDI part to be able to change settings in my keyboard with time stamps. Probably will make a html configuration page to select various parameters.

I been using it for a couple of rehearsals and tomorrow will meet the stage.

Opened an Olarm today and found the LTE antenna lying loose in the case. This board uses a Quectel EG915N LTE module with a little SMD PCB antenna soldered directly to the board. The RF pad ripped clean off the PCB.

Ended up doing my first ever micro-soldering repair:

scraped the RF trace

destroyed it

scraped a new section

rebuilt the missing pad using one tiny copper strand

lost that strand repeatedly

reflowed the antenna back on with hot air

prayed

It actually works. I don’t know whether to feel proud or traumatised.

Hi I'm making an Ethernet adapter that I'll mount in a flush wall box. Two ports will be PoE (access points), powered from the switch. The other two will be data only without power, also from the switch. The internet speed is 1 Gbps. For routing copper connections I'll follow standards (length, width) for 1Gb speed. Now I'm wondering whether to use a standard RJ45 connector or a connector that contains a transformer with filters for PoE usage. As an addition I was thinking of using two LEDs on the RJ45 connector — one for activity and the other for link speed. I would use a PHY chip. (I know the switch already has those two LEDs).

Opened up this active speaker with a failed SMPS, and found this absolute shit show. Precious repair tech was too lazy to remove the board from the frame and just botched a cap to the remnants of the previous, presumably exploded cap. FML, I'm checking this board extra carefully now.

Got my first PCB delivered from JLCPCB

So I got this thing chirping but I think the little battery powered amp/speaker I’m using is faulty. Super fun though if you have a busted Commodore 64.

the one on the left is the switched-mode power supply its much smaller and lighter, this one can output twice as much current as the linear power supply on the right

Made by a high school robotics team in MN