15 Dec 08 Linksys WRT54G Serial Console

Adding a serial port to your Linksys WRT54G, WRT54GS, WRT54GL and probably a wide range more is really really easy. The only thing we need is a serial to ttl converter. I personally followed the guide right here: http://www.rwhitby.net/projects/wrt54gs – works perfectly, and very well laid out. This http://www.compsys1.com/workbench/On_top_of_the_Bench/Max233_Adapter/max233_adapter.html is where I purchased my MAX232 kit from.

MAX232

MAX232

This is the device in it’s entirety. Leave the “Ct/Rt” unconnected, and connect + (+5V), – (GND), Tx and Rx according to the guide. You can then use your favorite serial terminal client to connect using 11500,8N1. You’ll need a null modem cable (serial crossover) to connect. Now it’s been some time since I worked on the Linksys WRT range. The earlier versions allow for a full firmware flash, later versions have seriously crippled hardware and a proprietory OS (VxWorks), and as such as pretty useless to hobbyists. If soldering this tiny board is too much trouble, you can also get hold of a MAX2323CPE chip, which only needs 4 ceramic capacitors to do it’s job.

Tags: capacitor, linksys router, MAX232, max2323cpe, serial console, serial to ttl, wrt54g

02 Nov 08 The Robot: Successful installation of Debian onto the Alix 3c2 board

Some hardware has arrived!

So my working space is a little bit of a mess at the moment. There’s no better way of getting started than just getting straight to the point.

The Alix 3c2 main board arrived in good health and works well. On the underside is a 512MB CF card and an Atheros MiniPCI Wifi. I’ve soldered single core wire to the I2C bus pinout. GND, CLK, Data & +3v.

I’ve also soldered bell wire across the power input. It accepts a wide input and so I’ve decided on 12v.

This is my prototype “power distribution board”. Currently it consists of 2 12V/2A regulators, some resistors and a 1000uF/30V smoothing capacitor. It provides 12v to the Alix board, and 12v to the motor controller. If both motors stall, they can use up to 6A, so whilst this is fine for testing the controller board, I’m going to have to replace one of the regulators with a transformer system to provide the necessary power to the motors.
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Tags: 12v, 38400 8n1, 3c2, 512MB CF card, alix, alix 3c2, atheros, atheros 5212, capacitor, card reader, clk, data, debian, debootstrap, gnd, Hardware, i2c, i2c bus, i2cdetect, Linux, minipci, motor, null modem, power distribution board, prototype, pxe boot, regulator, resistor, serial cable, serial console, smoothing capacitor, solder, transformer, wifi, wire

01 Oct 08 APNIC Box – Linux on a Mikrotik 532a, Part 1 – The Device

I put this device together for fun sometime around the start of 2007. The ideas that spawned this was using OpenWRT on a Linksys WRT54G access point. A surprisingly powerful and full linux distro with all kinds of advanced capabilities running on a Linksys wireless router which I’d previously thought to be a reasonably dumb device with computing power more comparable to a calculator than a PC. The project opened my eyes to embedded devices, and I wondered what device base I should start with. To cut a long story short and for reasons that I can’t even remember anymore I came across the Mikrotik Routerboard 532A and decided that I should start with that.

Conception

Here’s a picture of the device from the outside with some labels, view the full image to see them.

1. Status LEDs. Blue at the bottom left shows it’s on, orange at the top right shows that there’s wifi activity.
2. Ethernet (eth0)
3. Standard Serial Console (57600, 8 N 1)
4. Ethernet (eth1)
5. Ethernet (eth2)

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Tags: adsl2+, APNIC, APNIC Box, distro, ethernet, isp, linksys router, Linux, Linux routing, modem, openwrt, picolcd, public IP, redundancy, routerboard 532a, serial console, switch