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Author Topic: Spektrum AR6100e > Arduino Micro > Pololu DRV8833 > Tamiya RC260's  (Read 2041 times)

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Offline bpolitsTopic starter

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Building a small 3 motor RC bot. How do I make the receiver -> Ardu Micro -> Pololu Controllers communicate?

Bought 3 x tamiya gear/motor units, 2 for the wheels and one for the "weapon". Further research suggested that the

Tamiya RC260's motors need low voltage 3 - 4.5v max. Very few speed controllers go this low but the:

Pololu DRV8833 does, but will not interface with the:

Spektrum AR6100e directly, so we needed a:

Arduino Micro to link the RX with the motor controllers.

My questions revolve around 1) how to power the various units 2) how to make the Arduino hear the PWM signals and transmit to the controllers, etc., 3) I heard a heat sink would be good for the (Ardu?Controllers?), etc.

A rank adult robotics beginner here with electric RC Airplane experience, just looking for advice on where to look for info, or a tip on where to find where people have handled this before with low-V motors.

Thanks
« Last Edit: June 10, 2015, 01:34:21 PM by bpolits »

Offline bdeuell

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Re: Spektrum AR6100e > Arduino Micro > Pololu DRV8833 > Tamiya RC260's
« Reply #1 on: June 16, 2015, 11:02:21 AM »
1)
identify the power requirements for each of your components. if you require different voltage levels (i.e. can not use 5v for everything) you may need to build a regulator board (typically a linear regulators for each of the voltage rails would work for a project like this). arduino boards have an onboard linear voltage regulator. you do have to be careful not to overheat linear regulators as they are not very efficient especially for regulating down larger voltages.

typically you want to handle the motor power a little bit differently, it is higher current and can introduce noise into the rest of your system (causing problems). most motor controllers have separate power input for the motors and control. one option is to use separate power sources/batteries. it is also common to power the motors directly from the batteries and rely on the power supply to your control electronics to filter the noise. good design practice would include some filter caps to help with this.

2)
there should be arduino libraries to help with this and likely some example code. simplified: a command in your code will read in the signal from the receiver and store it as a variable. you can then do some calculations with those values and then another command will send a signal to the motor controller.

3)
the need for a heat sink depends on the power your components are dissipating. typically it is the higher powered components that are a concern (voltage regulators, transistors in your motor controller/h-bridge). the regulator on the arduino is not very big so be careful how much you run off it. you will have to look at datasheets and understand what specs you are using the components at to get an idea how hot they will get. it will not hurt to cool your components with a heat sink tho. one way to find out if you need to cool your components is to test them and see if they get hot in your application (you might destroy a component but often components are cheap). careful not to burn yourself and buy a few extra regulators ect.


 


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