26 Dec 08 The Linux Robot – Progress, Software & a Video

Over the past week I’ve made a couple of hardware improvements, as well as building the majority of the software library, a TCP server and making a good start on a client.

The camera draws over 350mA@12V and there’s no reason why I need it permenantly on. I’ve connected one of the Phidget Kit’s outputs to a simple transistor/resistor/LED circuit, with a 12V supply passing into the transistor’s collector pin, through the transistor, relay input and resistor. Then I’ve connected the camera’s power over the relay’s output. The power on and off for the camera/LED are now through setting the board’s digital output 0 to 1 and 0 respectively. Power consumption with no movement has now dropped from 1.25A to just under 0.90A. I’ve also put all essential USB hardware on one usb hub and all optional hardware on another (USB to TTL adapters, sound adapter) on the other. The optional hub is also on a relay now on the opposite side of the robot, and this now reduces idle power consumption from 0.90A to about 0.50A which I’m happy with.

I’ve spent a while working on the software site of things. I’ve written a ‘library’ in C which interfaces with the various hardware that we’re interested in. The library provides a number of functions, I’ve listed the useful ones here, and they’re hopefully pretty self explainatory: (more…)

Tags: 12v, beej, C, camera, collector, cvoiceengine, digital output, LED, Linux robot, phidgets, phidgets sensor, port settings, power consumption, relay, resistor, software library, speech to text, struct, tcp server, termios, transistor, usb hub, usb to ttl

08 Oct 08 Linux Robot, more hardware ideas

Follow on from: http://www.adamsinfo.com/linux-robot-watch-this-space/

I’ve been giving the layout and hardware of the device some thought. Hardware should be split up as follows:

Main board
At minimum, CPU, IO pin out, RAM, CF/SD, and USB controller. Wifi and/or ethernet would be nice. It will need to be linux friendly of course.

Custom IO board
Connect to Main board via 16 bit bus. The custom IO board will have some logic gate chips and maybe some memory. It will then connect child boards for LEDs, the ultrasonic sensors, switches and relays. The relays will then be connected to the wheels. I’ll consider adding other sensors for temperature, light, etc.
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Tags: beagleboard, custom io, Hardware, Linux robot, relay, Robot, sensor, switch, temperature, ultrasonic sensor

07 Oct 08 Linux Robot – Watch this space

I’ve been struggling to think of a good project to start on. I’m currently writing the APNIC Box series here, and I’m on part 4 of maybe 7 or 8 right now. I like to keep at least one personal project of interest on the go at a time so back to struggling for inspiration.. Feel free to tell me that this is an awful idea and suggest something else, but until I hear otherwise I’m going to roll with it.

Linux Robot – Requirements

Here’s what I’m thinking. Small embedded device, way smaller than the Mikrotik 532a used for the APNIC Box. The board will need USB [as we're going to use the 5v for charging later]. I’d like to start with a powerful enough board that it can be expanded later with relative ease.

The device will initially have few inputs and outputs. It will support miniPCI, USB, Serial Console, CF card, GPIO or some other good method for controlling a relay board and some motors. The device will have 4 small wheels, maybe rubber [old mouse] balls instead and some ultrasonic sensors, 4, 6 or 8.
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Tags: embedded, fm, Hardware, Linux, Linux robot, minipci, motor, oscillator, relay, Robot, sensors, servo, usb