26 Nov 08 The Robot: Hardware working and ready to go, a few minor glitches

Progress has as always been good lately. The robot boots up quickly and appears on the wireless LAN, with openssh running. The internal Atheros miniPCI wasn’t doing the trick and wireless performance was shaky at best. I’m using an Alfa Networks USB adapter (r8187) and an 8dBi gain antenna now, so this has some distance now!

I was also getting frustrated with the laggyness of the board while VLC was running for streaming audio and video and so I decided on an IP Camera (Edimax), which is connected directly to the LAN port on the Alix board (I don’t have any reason to use it for anything else).

The motor control script works well and the device is responsive. At this point I can drive the device around

relatively easily and accurately, stream video and audio back to my laptop, which again is connected wirelessly.

Using ‘espeak’ you can easily generate a synthesized voice to provide easy text to voice:

Everything is working great and I’m pleased so far. The only reason why there isn’t a video up yet is because I haven’t had the time! There will be one up shortly.
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Tags: 8dbi, alfa networks, alix, antnna, atheros, cf card, distance sensor, edimax, espeak, gain, hardware sensors, ip camera, Linux, motor control, phidgets, picolcd, power consumption, r8187, SD card, serial, usb, usb to ttl, vlc

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

13 Oct 08 Robot: Initial Hardware Order [rev 2]

Follow on from: http://www.adamsinfo.com/the-robot-hardware-list-wheel-plan-more-ideas/

Discuss in the forums

I’ve given up on trying to source separate motors, motor controllers, encoders and brackets. I’m concerned that my knowledge of mechanics and motors is limited, and that I’m going to spend too much time and money trying to build a movement package myself.

I’ve decided to go for a good motor/controller/encoder package here:

http://www.active-robots.com/products/motorsandwheels/rd01-drive.shtml

I’ll need two of these, and will have to replace the wheels with the omni directional wheel things I found and linked to in my last post.

I’ll drill the brackets into a thin metal plate, and start building perspex on top. I don’t seem to have paid enough attention to battery/device weight/motor/power and am concerned that the motor and battery combination will not move the device. I don’t yet have an idea of how much it will weigh, but I’ve realized that the perspex is going to have to be as thin and light as possible, and I’m going to have to bear weight in mind with any unnecessary or redundant extra parts.
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Tags: alix, APNIC, atheros, CF, embedded, i2c, Linux robot, motor, picolcd, Robot