PIC Microcontroller Webserver
Web Server for IP Remote Control
I’ve been wanting (needing) a way to control and monitor non-internet ready electronic equipment from a distance for a long time. The internet is a great way to do this. Here is a webserver that I made on perfboard that works very well. It has a 10baseT interface that is plenty fast enough to do what I want it to do. There are eight single pole double throw relay circuits, eight on/off inputs, and two analog inputs. The circuit uses a PIC18F4520 microcontroller with a ENC28J60 ethernet controller. The relay coils use unregulated 12 volts rather than the 5 volt bus to cut down on electrical noise that may affect the logic circuits and should also run a little cooler with the higher voltage. The relay coils are operated through a ULN2803 octal darlington driver. The digital inputs are isolated with optical couplers. Information found on the web indicates a PIC16F887 would work too. However, I plan on including a secure login and maybe some other features that will require the extra memory of the ‘4520.
Here is the first rendition of the PIC IP webserver put together on perfboard. This is the first perfboard circuit of any size that I have built in about twenty years. It is good to be back. Its phenolic smell reminds me of my first visit to a Radio Shack store in 1968. They were much more than phone/gadget stores back then and smelled like real electronics.