Hardware recycling

[JavaRN]

I am working on my second experiment and I need some additional hardware to make my robot more "sensitive" to the envrionment. I did this through two IR sharp sensors a servo to make the head turn and a sonar sensor. Now my question:

Some six months ago I bought a robopet for my daughter and as you might think she broke this poor robot. Insted of throwing it away, I took some servos from it. Now what do I need to do to make one of them work with my robonova, they use 4.5v to work and they have a standard red and a black wire connection. What I really want is that my robonova would be able to turn on a "fan" to blow a candle flame in response to a command.

Can anybody help me on this? As you know I am a newbie as regards to electronics so any help is really appreciated.

Thanks
Charles

[NovaOne]

Please include a photo of the "servo" from your robopet.

Correct me if I'm wrong but it sounds like its just a DC motor and gear box.

If it has three wires its should be fairly easy to connect.

If it has two, the red and black you refer to then you could use a circuit like this: (Note the MOSFET is over kill, but good for experimenting, ie use a smaller one once you know your current demand)

This circuit could be activated via a port using the STATE, PULSE, and TOGGLE commands



A diode or two in series on the +6v line will get rid of a bit of voltage, if the motor can'nt cope with much more than 4.5v

[JavaRN]

Thanks, I really appreciate your feedback. These are some photos of the motor:






Charles

[NovaOne]

Very interesting.

What part of the robopet did this device control?

[Robo1]

this might damage it but have you trued applying 5 volts to the red and black cables.

the other leads might be from the pot.

bren

[NovaOne]

I think you will find everthing you need at:
http://www.evosapien.com/robosapien-hack/nocturnal/RoboPet/mainboard.html#10
http://www.evosapien.com/robosapien-hack/nocturnal2/RoboPet

Apparently the robopet has 2 bit leg encoders and 3 bit encoders waist encoders
So I suspect you have several encoder wires comming off your device, check where you cut the wires from and compare to the pictures and diagrams linked above.


IF the red and black are motor connections, and you want to operate it as a crude "servo" I would use a small microcontroller to both accept pwm signals from the MR-C3024 and to drive the MOSFET.

Good luck

[JavaRN]

I found this

http://www.britishrobotics.com/pictures/BRCandice/BR650401Desc.htm

I did a simple diagram involving the above board to try to find how to connect this to my RN and motor and came out with this diagram:


(note: the old version of this diagram had the PWM port not the ETX port)


I've sent this diagram to the Robonova tech staff and they told me that I cannot use the PWM port and suggested the ETX instead. They also told me that providing power to the motor controller from the RN board might damage it.

My question now is: Can I use the LCD port instead of the ETX, since my ETX is already connected to the bluetooth module?


Charles

[NovaOne]

The motor could pull alot of current on load, so the Robonova tech staff are correct. Get you power from the battery directly; see page 4 of the manual for your motor controller. It wouldn't be a bad idea to include a fuse in this.

The LCD comms at 4800 Baud, 8-N-1, so if you set up you module to accept this you may be lucky[/url]