Finally I'd like to give you an overview about the technical facts.
The truck is controlled via a spektrum DX8i and an AR8000 (8ch) receiver.
The speed controller is a
Servonaut E20 with cruise control.
The motor is a
Servonaut GM32U370.
The sound module is a
USM-RC-2 from Beier Electronic
The cruise control is a very cool feature, but the change between forward and backwards is a bit complicated. The lever must be pulled down, after that it must be moved right (forward) or left (backward), back to center and upwards again to the middle. This is an annoying procedure, so I designed a small module based on an ATMEL ATMega328 to do this work for me.
The features:
A seperate channel is used changing the gears. It's a 3-Position switch representing forward, idle speed and backward.
If the gear channel is switched to idle speed, the speed is automatically reduced until the truck is standing still. This is measured by the sound signal the E20 is delivering. If the gear is switched to for- resp. backward, the module simulates the gear process defined by servonaut and after that the standard signal is send to the E20.
If the truck is in idle speed, you an play with the throttle, the sound module will receive the values to play the sounds, but the speed controller will recieve a "newtal" signal, it will not move.
Here's a video showing the
procedure.