Member Since: April 21, 2008

Country: United States


Programming Languages

Spin and PASM for the Parallax Propeller chip. Some C for PC and AVR microcontrollers.


Robots, data logging, wireless networks



  • This new breakout board (BOB) doesn't list the Hall effect sensors used. Fortunately the previous version of the BOB included a link to the datasheet of the Hall effect sensor it used. Here's a link to the Mouser part. Does anyone know if the new board uses the same sensor?

  • The new breakout board (BOB) doesn't list the Hall effect sensors used but the previous version of the BOB included a link to the datasheet of the Hall effect sensors it used. Here's a link to the Mouser part.

  • Thanks for the link to your Github. I have one of these boards and I hope to try your software.

    It's too bad about the documentation at Let's Make Robots (LMR) being deleted. RobotShop purchased LMR and instituted new terms of service. If members of LMR didn't agree to the new TOS, all their posts were deleted. The person who designed the ComMotion board didn't agree to the TOS so all the his posts were deleted.

    It was a very bizarre situation to see how quickly the new owners turned so many members against them in so short a time. If you read the comments of this Hackaday article, you can get an idea of what happened.

  • This one has power so it works on water.

  • I think part of this tutorial is confusing (and wrong). I think the statement "it’s also possible to load down a circuit too little - this may let too much current flow" is contradictory. If a lot of current is flowing the load will be high. I think the tutorial is using the term "load" incorrectly in this case. I assume the author meant it's possible to not add enough resistance which would cause too much current to flow. Too little resistance would cause the load to be too large not too small. There are power supplies (i.e. PC power supplies) which require a minimum load to work properly but power supplies which require a minimum load are the exception. As the author confirms elsewhere in the tutorial, in general one can not have too small of a load on a power supply. I think it would be a good idea to change the wording in this tutorial so the term "load" is used in a way consistent with its definition in this application.

  • Sorry for such a late reply, but I've used HobbyKing HXT900 servos in several projects and they seem to be very strong for their size.

  • 4 AA cells probably do not provide enough current for the 12 servos. You can find more information at this post on Let's Make Robots. According to above post, you need a minimum of 7V. You probably need a battery pack which can supply 3A or more. Many rechargeable batteries can source more current than alkaline cells. Edit: I should have read more carefully. I see you have the robot up and running. Very good.

  • I think the description should be clarified to make it clear there are (usually) four transitions per "click" of the encoder. You're right about the 96 transitions per rotation.

  • These are fun encoders. IMO, you should clarify the description to say the "24 Pulses per Rotation" means 24 full encoder cycles. Each "click" of the detent will transition the encoder through a full cycle of four transitions. There are 96 transitions per rotation (as Mayo2017 mentioned earlier).

    Since there are four transitions per detent click, pressing the button can cause the encoder to fluctuate a couple of transitions.

  • I've always been able to get them back off. I'm sure I've removed four different knobs from encoders dozens of times. I have had to pull pretty hard a few times.

No public wish lists :(