From the picture of the EVX-2, it looks like it is driven via a standard servo PWM connection. If that is the case, then it should work directly connected to a VEX Microcontroller motor port. You will need a pins-to-pins servo adapter to plug this in; something like this.
The thing I see in the specs that worries me a tad is:
[LIST]
*]BEC Voltage: 6.0 Volts
*]BEC Current: 2.5 Amps
[/LIST]
(BEC = Battery Eliminator Circuit)
I wonder if that means it will feed 6V at up to 2.5A back through the servo PWM connector. If so, you need to make sure and account for that.
The easiest & safest thing to do would be to NOT connect the red wire (white/black only) by removing the center pin from the 3-pin adapter I linked to above. That isolates the power systems of the Vex Micro and the EVX-2; so you’ll need to have batteries attached to both, and remember to turn off (or disconnect) both when not in use.
Disclaimer - I have no experience with he EVX-2, so the advice above is all guesswork based on a picture and a few bullet items.
If you need 2.5 amps to run the ESC then just use a transistor to amp up the signal from the micro controller.
Also add protection to the controller, by this I mean adding a diode which will prevent voltage spikes from damaging the sensitive chips in the micro controller.
I’m going to work with some electronics soon for a long time hours upon hours. I just ordered about $125 bucks in stuff from Sparkfun mostly assorted parts and sensors to play with! If I find an ESC to play with then I will see if I can do it.
I think it is the other way around. I think the ESC will provide 2.5A back to the Vex over the red wire (that is what a BEC usually does). Unfortunately, the documentation for the EVX-2 doesn’t seem to provide any other hints about what these two BEC numbers actually mean.
The microcontroller already has current limiting resistors, and (I’m fairly certain) clamping diodes. There is certainly no harm in adding external protection circuitry too, but it shouldn’t be necessary in this case.
That makes since because that would allow the battery to have one connection. The battery would be connected to the ESC and that would provide power to the motor and the control circuitry. So yea just don’t connect the red wire to the vex micro controller as was stated above and you should be safe.
Correct I want to use the ESC and separate battery packs (all vex will be controlled off the vex battery packs) to control a 2 /550 size motors, these motors will be hooked to a 2 speed transmission that will drive the front and rear tire/wheel assemblies, this will be used as my platform to mount all vex to, the steering will be vex servo, only non-vex control would be the ESC.
I want to run everything through the Vex transmitter/receiver setup.
The US military uses this platform to blow up bombs in Iraq. They have this platform with camera and assault shotgun mounted on it, it is fast, strong, 4wd and can be 4 wheel steering equipped. My e-maxx will bull a 13 year old boy on a skateboard up a 4% incline at +/- 10 mph. Oh ya you can also get 4 individual track systems for it…So I figured it would be a great base…
