alessio70
Heliman
Location: Perugia - Italy
| for those who are interested in our little project of an RC to USB interface... (PPM, PCM, and now also ADC... http://rcjoyng2.qstep.net/)
- from version 3.3.0 the firmware also implement ADC mode: if someone has a radio not equipped with PPM/PCM or has old unused or malfunctioning radio, now has the possibility to directly connect its potentiometers/switches to PIC analog inputs AN0..AN11 (JP4 and JP5 on the new through hole PCB); firmware uses the PIC internal ADC to sample these inputs (voltage in the range 0-5V) with a resolution of 10 bits (1024 levels); up to 9 channels can be read in this way with 28 pins PIC18F2455/2550 (up to 12 channels could be read using 40/44 pins PIC18F4455/4550). See manual on our site for details.
- from firmware version 3.2.0 the interface become a full speed USB device to get around constraints on speed and report size imposed for low speed devices by USB specifications; this means that at last we can have more proportional axes per joystick without loss in resolution: the current version implement two joysticks with 8 proportional axes each (up to about 5000 points resolution each) and 8 buttons for a total of 16 proportional axes and 16 buttons (32 controls). Anyway the traditional low speed interface firmware binary with 4 axes per joystick is still available inside the software package and is compilable by just setting a define; polling interval for interrupt transfer is now set to 5 ms (and could also be set to 1ms) to minimize input latency. The new version does NOT need any hardware mod... only firmware changes.
a summary of the other features:
- smd (4x2cm) or through hole (6x2.5cm) PCB and very few components
- uses the new chips from microchip 18f2455/2550 that have a flash program and data eeprom and then are programmable more than once (useful for programming firmware updates available on our site)
- assignments of channels and joystick controls are configurable by editing a txt file configuration and programming it directly via usb with a simple utility; assignments configuration remain stored inside PIC non volatile data eeprom so there is no need to reprogram it after disconnecting
- it should be compatible with virtually all radios equipped with a PPM output, and it's also able to decodify some type of PCM signal (for now Futaba PCM1024 and Sanwa/Airtronics PCM1/2)
- it should be compatible with virtually any RC or flight simulator that can make use of the system joystick
- the firmware work also under linux (and the assignments utility should be quite easily ported on linux linking against libusb instead of LibUSB-Win32) and as an HID peripheral should work under every OS with HID USB support
- an extensive manual is provided on our site, with hardware, software, assignments, and also modulations description
- the source is extensively commented for the ones who need to personalize it
- the project is totally free and suggestions and reports about it are very appreciated
you can find it at:
http://rcjoyng2.qstep.net/
enjoy it 
alessio e andrea
http://alessioandrea.qstep.net/ |
