Update: I rebuilt version 1 with a body of wood this time, and added a bunch of new stuff:
A powerswitch which cuts the power between the motherboard and the batteries. This was convenient before I figured out how to make the kill-switch work.
A kill switch: a simple switch which works with an interrupt which stops all activity.
2 LEDs. I had 2 leds from some cheap solar garden lights (the rest of the electronics had stopped working). Making them blink at different times was fun. When it turns it's head or makes a turn, the led on that side goes on. When it's moving forward, it blinks in rapid fashion. When it stops completely, both light light up for a second.
sometimes it got into a deadlock situation, where it just kept turning left and then right and back again. I added some extra code which checks if 3 turns have been made without forward movement and then does a longer turn to resolve the deadlock.
I also fixed the turn the previous one was making, there was a bad soldering connection on one of the motors and it wasn't getting enough juice.
See the video here: http://vimeo.com/26928481
Older text:
Ordered the LMR kit from Solarbotics, paid the amazing shipping costs to get it from Canada to Europe, and then had to pay additional VAT. Ouch. I guess I'll spend the time searching for parts in European webshops from now on.
Built it in 2 evenings. Got Frits' 'shbotvideoprogram.bas' to work, although I got it to balance, it then gets confused whenever it starts driving and tips forward, thinking there's an obstacle in the way.
The program in the tutorial itself (very nicely written by the way, thanks Frits!) doesn't seem to work, haven't figured out why yet.
Not sure if you already checked it out or not, but you might give this link a look over. Good luck on getting it all worked out. I can’t wait to see more.
Congratulations! You’ve taken your first steps into a larger world…
If you are having trouble with the program, tell us specifically what isn’t working. Sometimes a video of your robot in operation can help us see what is going on most clearly.
Thanks for your offer for help, ignoblegnome. I’ll post the code I have and well the robot really didn’t do anything when I started the tutorial code. Doesn’t seem to like the loop ‘main’ cause if I put some wheel commands or servo commands before it, it does do that.
Thanks for that, walkercreations. I hadn’t seen that yet.
By using a bent paperclip in the front and a spring from a clothespeg in the back, the robot now no longer tilts forwards and backwards and moves around a lot smoother. Now gonna play around with the code.
I’ve uploaded better pictures and some details of the back and underside.
Well, I’ve done all 3 checks, and when I was reassembling my motor one of the leads came off the motor so that might be my problem. However, now I don’t know what kind of lubrication I need for my gearing mechanism? Some googling for servo gear grease leads to ‘silicone grease’ or ‘synthetic grease’. Does that sound right? I don’t have any in the house of course, but I could go get some tommorow.
Hehe yea I guess but it gets kinda boring when it just goes in circles all the time.
Yea I changed that. When I was debugging faulty code earlier I’d upped it to 1000 (from 300) (and then made the video to show the turn), but now I’ve set it back to 250 which is perfect, it turns exactly as far as the sensor on the servo does.
When I put some of my first RC cars together, it was suggested that I use Vaseline as gear lube. I don’t know if Vaseline would be too thick for smaller motors or not.
Thanks for the replies guys, I’ve found a shop closeby that sells the stuff and gonna get it next week. It seems the long turn was a crappy connection on the motor. I’ve resoldered it (along with a new body - will post pics soon) and it seems to be going straight now, although it’s only doing very short burst of forward motion (dunno why yet).
Can someone with PICAXE 28 board experience please look at picture IMG_6777 (attached above) and tell me what pins are what in the code? I have 2 LEDs, which I can control with ‘high 2’ and ‘high 3’. The yellow and the blue wire go to one LED where the yellow goes to the cathode and the blue to the anode. The other led has red as + and black as -. The pin labels in de code don’t seem to correspond with the pins on the board? so why does it work at all? I would expect to have to turn the + and the - around on board to have the LEDs work.
Also if I move the - leads one pin to the right, the leds become superbright, but they aren’t being controlled by pins 2 and 3 any more.
I can only conclude that I’m controlling the anode pins now and somehow they are lighting up even though the polarity is wrong??
The red/black LED wires are connected in reverse. For control, maybe, you could could try B.2 and B.3? Reverse polarity to LEDs should get you squat, no matter if you pulled them high or low.
Somehow I had it in my head that the big piece in the LED was the + and the small bit the - but reading the pages on the web again it seems I got it wrong. I took my multimeter-meter to the pins and the leds and now I think I’ve finally got my head wrapped around it. Yea the red and black wires are soldered wrong to the LED; I guess I need to RTFW (web) more.
