Recent blog entries for gear21

I just got back from a week and a half of driving through the west. Saw and did many things :). Haven't worked on the robot in a couple of weeks, but plan to this weekend. I did get a chance to install a backlight 'hack' on my gameboy advance though, and it works very well... it's pretty cool.

Well, I have the speed control problem narrowed down to a grounding issue with the logic control... (which is what i thought originally). It's been tough to narrow down exactly what the problem is because there are so many variables - changing just about any of the lines causes different behaviour. So it's some combination that doesn't play well together...

Finally installed the hardware and software for the IR ranger and the servo for sweeping it back and forth. It's working great! Adding the servo and code was amazingly simple and didn't take very long at all. I'll have pics of it up on my site soon.

The only major bug left is a speed control issue... one of the motors goes considerably slower than the other, and I still haven't figured out why... I've swapped controllers, motors, connectors, and more... but it still hasn't made a difference. Once I debug that, it should be ready for some real-world testing, and some development/expansion of it's primary control software.

The "primary control software" is on a laptop right now. It talks via the serial interface, sending commands like "F1", "R1", or "I3", and the OOPic resonds with "ACK FWD SPD1", "ACK REV SPD1", and "ACK IR3 00023" (IR is InfraRed ranger). I will be adding ALR (alert/alarm) messages the OOPic will send to the control software as well. It's getting pretty interesting now :) I could do all that on the OOPic, but I want to keep it as sort of a "reflex" mechanism, and keep most logic and decision making on the laptop/palm/WinCE device.

6 May 2002 (updated 6 May 2002 at 17:01 UTC) »

Spent the weekend tracking down electrical gremlins... everything from a bad cap to a drained battery :)

The PCB from express PCB came in on the 2nd, and I am very happy with the results. They look SOOO much better than all the wires all over. Also received two more servos from acroname, so I can mount the range sensors on them.

I finished adding the OOPic programmer's manual to the oophq.com site, and it can now accept user comments and additions. I've still got to fix some of the internal links, but I have to wait until the Object documentation is installed.

My printed circuit boards should arrive from ExpressPCB today! My bot hasn't run since I ripped it all apart to redesign a few things, and this is one of the last "major" changes. It will eliminate a huge part of the "rat's nest", as well as make it more modular.


Also, while I was at W@lM@art yesterday, they had a cheap (<$12) "remote control" truck. It's controlled by 4 wires connected to a simple left-right & up-down mechanism (like a really cheap radio transmitter. I ripped it apart, and it looks like it will work great for experimenting with. The control is a very simple mechanical h-bridge, but I'm just going to drop it for one of the H-bridge chips (the motors are pretty small). If you're looking for a cheap base, this one should work for basic projects...

This weekend I also got the OOPic to talk to my Palm Pilot via Serial connection. Works great! I can send it commands through a palm pilot. But I haven't decided which one to use - a laptop PC, or a palm. Programming the laptop is a lot easier, but the palm is nice and small, with longer lasting batteries.... decisions, decisions. I will most likely prototype on the PC.

I also started a OOPic related website on Friday. It's at OOPHQ.com. (OOPic Headquarters). If you have OOPic content, feel free to send it to me ;)

Two events have happened recently for my bot...

First, I completely messed up my "connection board" for connecting my oopic to the rest of the bot (basically, where I convert from the 40pin IDC cable to a board, then go to the different sub-systems)... It's so messed up, I have to scrap it. BUT, I finally sat down and used the easy to understand printed circuit board software from ExpressPCB, and laid out a nice board without so many wires that I can mess up. I'm reviewing it tomorrow, and I'll send it in tomorrow afternoon. I'll let you know how it comes out.

I also finally soldered together the CompSys1.com rs232 kit and installed it... My bot was talking to my pc through the serial connection in less than 20 minutes. I think this will help a lot with debugging, now that my oopic2 programs are getting more complex.

A quick note on soldering... If at all possible, DON'T use a radio shack $9 iron. Get a nice one with a fine point. And use flux. I used a $9 iron for years... and if I had known a Weller was this much better I would have sprung for it a long time ago... it's worth every penny.

The pics are up! I put them on my site as pdc01- pdc07.jpg. In case you're wondering, the structure is a spare 3.5" aluminum drive holder from my PC case. (Lian Li rocks, btw).

Looking down on the connection strips, the left is for +12 (unregulated), the middle is +5 (regulated), and the right is ground.

Other than essentials, everything is still removed, as I revise my mounting plans.

Ahh.... finally...rewiring complete and tested. Took a bit longer when there was a bad switch in my circuit, but once that was replaced, the new power distribution center is working great. I took some pics, but haven't uploaded them yet.

Now that I have a new "Power Distribution Center", I've been completely re-wiring the external switches, sensors, and everything else... It still looks cleaner, but it's taking a while.

I started planning out the new "control panel" orientation, and I bought some clear laser printer stickers, so I can correctly label each of the switches, lights, and the LCD that just came in from AllElectronics.com.

Also received an RS232 module that will make connecting and disconnecting to a serial line much easier. I ordered it from CompSys1.com this weekend, and it arrived yesterday. Looks neat... now all I have to do is solder it together and try it out! :)

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