Wednesday, October 18, 2006

I miss embedded

So I picked up a Olimex PIC-MINI-WEB standalone ethernet PIC. It's basically a Microchip PIC controller bolted to an ENC28J60 Ethernet interface. It's preloaded with Microchip's TCP/IP stack and their embedded webserver.

It's very tiny and only cost me $39.00 without the power adapter.

It includes full source code for the whole thing (TCP/IP, UDP, SNMP, DHCP, HTTP, FTP, TFTP, ARP, Ethernet, boot code). Looking through it takes me back to my days at 3Com working on the OCLM. It always amazed me we could fit so much into so little space. This device has 32KB of onchip flash, 1024 bytes of RAM, and 1Mbit in a serial EEPROM (yeah, that's 128KB).

My original plan was to hook it to a Dallas 1-wire digital temperature sensor so I can monitor the computer room temperature at work (and generate SNMP traps, alarms, email, etc). Also want to rig it up to send the data to my website on a periodic interval, so I can compute graphs over time. Had a few other ideas now that I started playing with it:

* promiscuous monitor for packets on TCP port 143 or 110 that include the byte sequence PASS
* IR to Ethernet bridge for controlling my cable box (or other remote control devices)

Probably the biggest annoyance is that it needs a 6V DC power supply to keep it going, so I have this tiny little microcontroller connected to a big honkin' AC adapter. Will have to measure the current draw and see if battery power is viable. On the other hand, this month's Circuit Cellar had an article on Power over Ethernet solutions. Maybe I can see if Eric has any samples kicking around from his days at Enikia...

The other annoyance is that unlike the OCLM, the device is not field programmable, so I need a PIC programmer. Unfortunately the cable advertised by the website was the wrong one, so I have to wait a few more days for a $3.95 adapter before I can get started. Doh!

I miss embedded work. Feeling kind of annoyed about the situation at my job. Feeling undervalued. Stuck doing something I'm not really enjoying and not feeling fairly compensated for being stuck doing something I'm not really enjoying. Maybe it's time to move on.

Note to self: block source IP