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

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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.

Power Usage

Power Distribution

Alix 3c2

The power usage is 0.35A@14.4V when the board is fully active, and 0.26A@14.4V when booted and idle. I’ve set the power source to 14.4V as this is my intended battery rating at the moment.

Debian has been successfully installed. I installed it on the host machine to the CF card using debootstrap and a USB card reader as it was going to be easier and quicker than installing it on the device directly via PXE boot (which incidentally the device supports).

The serial console settings are 38400 8n1 and is accessible via a regular null modem cable. If anyone wants a card image at this point, just ask!

My first problem has been encountered communicating with the motor controller. I have connected the GND, CLK and Data pins however the controller shows no sign of I2C life.

I have loaded i2c-core, i2c-dev and CS5536 kernel modules, and i2cdetect shows a detected CS5536 bus. Running i2cdetect to scan the bus shows nothing, and attaching an oscilloscope between GND and CLK or between GND and Data shows nothing more than <10mV line noise. I’m guessing it’s not going to end up working this way, and so I have two choices.

1. Purchase a USB to I2C adapter which seems to be documented and supported and hope for the best
2. Return the motors and controller, and purchase an ‘all in one’ drive and controller system with USB communication or similar which I do feel would be both expensive and a bit of a let down.

Either way, Debian is installed and working, and I’m awaiting delivery of the USB sensor kits. I’m going to contact the manufacturor (Devantech) of the motor controller/motors package who have so far been really helpful, let them know my test results and ask whether it would be advisable to get the all in one USB to I2C host controller. If so I’ll give it a go and if I still have no luck, I’ll return the units and purchase an all in one drive system.

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

Reader's Comments

1. Dimitar Boyadzhiev | 10 Jun 2009 9:07 pm

   Hello there! Nice project. I’m also into alix computer board for robotics purposes. I wonder if there is really a need to have a CF card, there are times more expensive than standart flash sticks. And I was wondering how much did the wireless module cost you?

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