Sunday, September 21, 2008

Videos, videos, videos

Here is a pair of new videos, the first containing the obligatory crash... I have modified the earlier code to include some basic logic for turning either left or right when confronted with an obstacle.

Now, back to study...


  1. This is looking really cool, how are you controlling image processing and motors at the same time?

  2. Initially the robot's motors are just turned on and left on. Then it loops through a check for obstacles about 7-10 times/second, stopping the motors if something is detected. The robot then performs some timed movements (reversing/turning), before returning to the top. So, its pretending to multi-task :)

    Cheers for your comment, by the way, let me know if you have any other queries.

  3. Did you modify the servos for continuous rotation or are they continuous rotation servos?

  4. The servos are the ones that came with the Rogue Blue chassis, already modified mechanically for continuous rotation, but retained their standard servo electronics. I removed those electronics, and installed the L293D motor drivers. Short answer; a 50% yes on both counts.

  5. Really cool project. What kind of batteries do you use to run Microclient? Do they run out fast?


  6. Hi Zee,

    I am not currently using the Microclient Jr as I leapt onto the Arduino bandwagon when I saw how easy the Stickduino was to work with (although I fully intend to use it again after I have got the low-level wall avoidance working through the CMUcam and Arduino). The Microclient runs off a 5V 3A power supply, 3A being the absolute maximum rating (more like 1A with minimal accessories).

    My intention was to combine a pair of 7.2V 4200mAh RC Car battery packs for a total about 14V, and use a decent quality 5V regulator (LM338K?) to step back down. I was (being realistic about losses) hoping for about an hour of runtime with this set up.

    I chose the RC batteries as I already have a RC charger and the cost is not too bad really.

  7. I have another question, How do you power your servos? Is it separate to the Arduino? Currently i have a ultrasonic range finder and two servos and the Arduino cant handle it (due to lack of current i think) any suggestions? Can i hook up some AA batteries to the servos and share the ground with the Arduino's ground?

  8. I am wondering if we can run the microclient using a smaller sized battery (Something like 4 AA batteries)? Is it possible? What do you think?

  9. I figured out my battery/power issue. Turns out i was right.

  10. Hi Zee, sorry to not get back to quickly.

    You could possibly use 6xAA's for 9V, or 8xAA Rechargables for about 9.6V, but you have to drop it to 5V for the Microclient. The 6V that 4xAA produces would probably be hard to drop to 5V, as as far as I know most regulators don't like small drops. The next problem is the current draw. Assuming a draw of 1-2A, a set of 8xAA 2000mAH Ni-MH batteries would not last much more than a hour on a full charge (taking into account losses in the regulator). This would be ok, if like my robot, 5 mins is the max time before the robot runs gleefully into the wall :D

    So, short answer, AA's would work, but only with a higher number than 4, and with probably a max 1hr run time.

  11. Hi Pathologic,
    I am using 6xAA (passed through a 5V regulator) to power the electronics, to give me a long-term stable supply, whilst the servos run off a 7.2V LiPoly battery pack for quick and easy recharging (its from my RC heli) and light weight.
    As you have discovered, all you have to do extra is common the earths. I am upgrading the wiring on the robot to have a terminal strip connection for 5V, 7.2V and 9V to power extra addons, I will post about it as soon as its done.