15 Jan 10 Embedded Linux Programmer

As an embedded linux programmer, I’ve had the opportunity to work on a number of different platforms, MIPS being one of my favorites.

There are a few general limitations that you’ll find. You have limited CPU power available, you have very little RAM available, and for more advanced operations and optimizations, your CPU will generally have a limited function set.

The usual good programming practices apply, but are of much greater importance. Specifically, don’t allocate memory that you don’t need, and dont put the CPU under undue stress with unnecessary or badly optimized loops. Taking C syntax and some pseudo code;
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Tags: assembler, embedded, loop, mips, optimize, x86

19 Sep 09 Installing Linux on the Embedded PPC50 Touchscreen

I personally really like this touch screen PC! I’ve installed Debian (of course), graphical interface, and configured the HUAWEI data card along with the TSCOM touchscreen drivers.

I also modified the boot up to log in and start the graphical interface automatically. Using xvkbd for a virtual keyboard works really well, and I might just have to carry this around in the car along with the datacard for those emergency situations.

It’s a simple x86 with 1GB diskspace and 1GB RAM. The device takes a simple 12V/6A input and therefore wiring it up to a car, battery, or other portable power supply shouldn’t be a problem!

Any ideas what next?

Tags: datacard, debian, embedded, Huawei, Linux, ppc50, touchscreen, tscom, x86, xvkbd

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

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

15 Sep 08 Using picolcd on linux, lcdproc, routerboard, liblcdusb

I’ve posted previously about my embedded device and picolcd. I wanted to put some thoughts down about using picolcd.

The easiest way to drive your picolcd is with lcdproc I’ve found. The device doesn’t require any special drivers which is great, as long as you have USB support working you’re fine. Make sure uhci-hcd and usbcore are loaded, you should be able to use ehci-hcd as well as it supports USB 1.1 and 2.0 but I haven’t tested that.

Use lsusb to make sure that the device is shown and recognised. If you see:

    Bus 002 Device 003: ID 04d8:0002 Microchip Technology, Inc.

then great. Your device is connected, working and your machine supports USB.
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Tags: drivers, ehci-hcd, embedded, lcdproc, libhid, liblcdusb, libusb, lsusb, pico lcd, picolcd, picolcd on linux, routerboard, uhci-hcd, usb, usbcore