752 Wiring Help - RC Car

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752 Wiring Help - RC Car

Postby t100owner » Wed Jul 25, 2012 9:39 pm

Hello -
I recently purchased a 752 controller to handle turning lights on and off from the transmitter. I thought I had everything hooked up but things aren't working. I connected the black wire to ground, red wire (constant 6v) to IN and white (.3v with switch off / .6 with switch on) to the VRC spot. I checked all voltages using the other half of a servo extension cable I purchased from Pololu and got the readings from above. When I plug in the wires to the receiver, the white (.3v/.6v) goes dead, 0 volts. Red and black behave as before. If I disconnect the white wire the voltage to the wire returns. At a loss as to what is happening. I can provide pics and such if that would help.

Thanks for much.

Dave
t100owner
 
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Re: 752 Wiring Help - RC Car

Postby JonathanKosh » Thu Jul 26, 2012 10:39 am

Hello Dave,

I am sorry you are having trouble with your RC switch. I noticed two things about your connections. First, in your description IN and VRC are reversed from what they should be. The servo red wire should be connected to VRC and the white wire should be connected to IN. The pins are arranged on the board so that you can just connect a standard servo extension cable from your RC receiver without rearranging the wires.

Second, VCC and GND on the right hand side of the board will need to be connected to an external power supply for the device to operate.

Alternatively, if you can safely lower the RC receiver voltage to less than 5.5V, you can short across the two adjacent pads on the back of the board, connecting VRC and VCC together. This will allow you to power the digital device through your RC receiver.
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Re: 752 Wiring Help - RC Car

Postby t100owner » Thu Jul 26, 2012 7:51 pm

Thank you VERY much. Worked perfectly once I got all the wires in the right spot. For anyone searching on this in the future, here is what I have done.

From Receiver:
White - In
Red - VRC
Black - GND

On 752:
Connect pads between GND terminals (Don't short to the grounds)

To Lights:
Neg - Gnd
Pos - Out

This is giving me the correct voltage when the switch on my remote is turned on and 0v when off. I wish I had gotten the receiver to 752 board mentioned above, would have saved me a lot of work. This was plugged into the 3rd channel on a traxxas receiver. And major Kudos to Pololu for taking the time to answer a question on a inexpensive part, I'm impressed.

Thanks
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