26 mai 2009

Very short howto build RCHv2

Withing few hours, provided you have the right components, you can build your own RC transmitter.

First, an important component is the transmission itself. Any module with PPM signal as input can be used. For its low cost, I choosed the Assan module (Hack version X8D) with Assan receivers. Cool price and so far works fine. It is powered with 5V.

The transmitter box is a very low cost transmitter such as those sold for RC simulator (FMS) http://www.flashrc.com/bmi/2637-gamepilot_boitier_simulateur_usb.html . Remove everything except the sticks and switches of course:

The micro processor is an Atmega 644 DIP, with the external crystal and 2*22nf condo. It must be flashed with the RCHv2 software:

Two small board are screwed in the plastic box, one for the micro-controller, the second one for the micro SDcard and the 5V power regulator. Do not forget the led also on the transmitter front.

One the right side, the UART plug to connect to the PC for the radio configuration (it's hidden on the picture between the protoboard):

Connect all the sticks, switches, the Assan module and SDcard board together:

And that's it, the last step will be to close the box and to configure the micro processor with the PC to set the mixers and settings:

Some more comments

Last week-end first flight was smooth, even more than expected. The RCHv2 behaves exactly as I expected, even if the Transmitter power was very close to the limit (LM317 to produce 5V with only 5cells Nimh).
The Assan module and the very small long range 4 channels receiver with a very short antenna (2cm) worked perfectly in the "Weasel" wing. No problem even when flying far from me (the wing is approx 90cm wing span) and even with the antenna transmitter pointing directly to the wing.
Nice pleasure to fly with this wing and your "own" transmitter :)

21 mai 2009

Home made RC for the summer and travels

Here is my new home made RC. It features 8 channels, a module 2.4Ghz Assan for transmission, configuration by PC, Micro SD 2GB, mixers, and settings fully configurable by the software.
The transmitter box and sticks comes from low cost transmitter (could have been a RC joystick).
The microprocessor is an AVR Atmega 644P, and the software is my own called RCHv2. My brand new flying wing "weasel" will be the beta tester. More to come soon...

18 mai 2009

More to come

I have been working hard on RCH recently. PC configuration through command line is working, model storage on SD card, and connection to PPM module.
Stay tune for more details of this transmitter hack soon.