Cable Butchering For Logic-Level Serial

Early PCs and other computers had serial ports, sometimes as their main interfaces for peripherals. Serial ports still survive, but these days they are more likely to have a USB connection into the main computer. However, when you are working with a microcontroller, you probably don’t want a proper RS232 port with its plus and minus 12 volt signals.

You can get converters that specifically output logic-level signals but you probably can’t pick one up at the local office supply store. They might, though, have a normal USB to serial cable. [Aaron] had the same problem so he hacked into a cable to pull out the logic level signals.

On the one hand, hacks like this are a good inspiration for when you have a similar problem. On the other hand, you probably won’t wind up with the same cable as [Aaron]. He got lucky since the board inside his cable was clearly marked. Just to be sure, he shorted the transmit and receive lines to see that he did get an echo back from a terminal program.

Unsurprisingly, you can also repurpose an ESP8266 to perform this same task. Or, you can use a cable as an I/O device.

DIY $6 serial cable for vintage Apple QuickTake cameras


Knowing he was a guy who liked electronics and taking things apart, one of [Erik]’s friends sent him a vintage Apple QuickTake 100/150 digital camera as a bit of a joke. [Erik] enjoyed the gift, but since his friend hadn’t sent the necessary serial cable he really couldn’t do that much with it. He searched online only to discover the cable is very difficult to find these days, and thus very expensive. So, being the handy guy he is, he built his own.

Starting with an Apple MiniDin8 Male cable, he cut off one end and attached the wiring to a RJ45 connector. That got plugged into a modular adapter with a DB9 Female Plug end and wired up. The procedure required no soldering, and cost less than $6. Awesome.

Unfortunately the lack of serial cable isn’t the only problem he faced. QuickTake isn’t compatible with newer Apple computers that use Intel. You have to either have a much older Mac, or use a Windows XP emulator. If that wasn’t bad enough, the cameras only want to save photos in QuickTake file format. Luckily, [Erik] documents how he overcome all these issues in his post.

[Thanks Erik]