Recent blog entries for horar

The first version of the robot simulation software that I've been writing is producing useful output. There is an animation of the previously posted finite state machine driving a simulated robot around a small toy world on my website at Will be posting the source code for it too, once it has been cleaned up and documented a bit better.

Having done a fair bit of testing and refining on the finite state machine code, I've posted it on along with the definition for the diagram posted yesterday, and a sample script that runs on it. I guess the next step is to create a simple robot simulator to go with it.

There is now a page containing sample output from my Finite State Machine software.

In addition to being able to execute the FSM in a simulation, this program can export the FSM definition as a Graphviz file to produce a very useful graphical rendition in various formats such as Scalable Vector Graphics.

The main goal here is to be able to compile the FSM into efficient assembly language code for the PIC16F88 microcontroller and that's going to take a little longer. I'll be making all the source code available once that is working properly.

Hi everyone. I've made considerable revisions to my website at and added a great deal more content for robotics and hydroponics.

Lately I've been working on a bootstrap loader for PIC16F88 microcontrollers, and a simple real-time operating system to go with it. All the common lisp and PIC assembler source code for the hardware programmer and bootstrap loader is available from the website now.

A related project to create an effective very high level programming language for PICs, based on finite state machines, is also well under way. I would appreciate hearing your thoughts on the topic.

10 Feb 2006 (updated 4 Mar 2006 at 12:01 UTC) »

I am curious to know what software everyone uses for capturing circuit schematics for their robotics projects. I've tried quite a few different packages over the years and have never been particularly pleased with any of them. Of course there are still many that I haven't seen yet. Do any of you have any recommendations, especially for open source software to do this?

Yesterday I decided to try an alternative approach and created a schematic of a slightly modified version of David Tait's classic serial PIC programmer using scalable vector graphics. SVG is the up and coming web technology for creating high quality 2D graphics on web pages. You can see the results of this first test here converted to a gif file, since most web browsers don't properly handle SVG yet. The SVG source file for this can be downloaded from You may or may not be able to view the SVG file directly in your browser.

PS Just noticed and fixed the broken link to the SVG file.

Over the past week I have been developing an effective bump sensor to reduce the risk of damage as Ally careers around the room. Owing to the larger size of this robot, something a bit more sophisticated than whiskers was needed and I am very pleased with the result.

I've spent some time this afternoon updating my robotics website and there is now considerably more there to interest my fellow robot builders, including details of the bump sensor. Please drop by and check it out.

18 Jan 2006 (updated 18 Jan 2006 at 15:15 UTC) »

I've set up a webcam covering the part of my work area devoted to robotics. You can see what is happening with my robots at any given time by pointing your browser at Update Implemented a work around for a file permission problem with the uploaded webcam image. After working perfectly for weeks, today of all days the webcam daemon suddenly began to misbehave.

After lurking on a daily basis for several years, I have finally created an account on I'd like to take this opportunity to say hello to everyone. I'll endeavour to post some pictures and descriptions of my robotics projects in the coming weeks.

If you'd like to say hello informally, why not drop by the #robotics channel on the IRC servers and introduce yourselves.

There are a bunch of hard core robotics geeks there ranging in skills from interested groupies to professional robotics researchers. We hail from all corners of the globe so there is almost always someone awake.

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