RS232 switch, and thank you Mister E

[Demon]

Here's a little something that I've been dying to have since I started working with PC/PIC communication. It's a switch between the serial programmer and a MAX232 chip.

http://www.xavierkamial.com/Videos/Power%20supply%20-%20RS232%20interface.JPG

I was fed up with doing the plug/unplug the RS232 connector dance and Mister E suggested I look into 5V relay switches. I found some for $1.99 each in surplus at a local electronics store, add $0.79 for the switch, and it's all I needed.

I highly recommend you invest in SIP headers to make custom 9-pin connectors. Crazy glue, a 5 pin strip and a 4 pin strip make an instant DB9 connector if you're careful with your fingers. I just slid them into the female, applied the glue and then squeezed them with a mini-clamp. PRESTO! Perfectly aligned custom DB9 ready to have wires soldered, and all my fingers work independantly!

I picked up somewhere about placing 1N4001 diodes across the power pins on the relay switches (from - to +). Don't ask where, they said it was a safety precaution for residual AC electricity in the coil and that was good enough for me.

Thanks dude, this is just awesome. I can program and test with a flick of the switch!

Robert
:D

[Demon]

For those like me that knew nothing about relay switches, this is what Mister E showed me:

http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=123118

Mine are very similar, except for pinout. Don't assume all pinouts are the same, they are not. My common leads are the 1st set after the power pins, not in the middle of the other pair. With just my luck, there are no datasheets on the web for my particular model, not even on the manufacturer's site.

The +5V pin will have a bump or some sort of identification like on MCUs.

Robert
:)

[Demon]

Dyslexic keyboard.

That is supposed to say DPDT SWITCH on the pic.

Robert
:)