USBASP to PPM2USB Conversion
Hardware-Modification
The hardware of known AVR ISP Adapter "USBASP" can be obtained at E**y for a few euros. The schematic of the PPM2USB-Adapter is nearly identical to that of the USBASP. Therefore, it is easy to use this board as a PPM2USB-Adapter. Unfortunately, the ICP pin (Timer0, input capture) is connected to USB D+. Instead of reroute D+ to another pin, the hardware was kept 1:1 and the internal analog comparator is used. Advantage: You only need to solder one cable and the board remains compatible with the original USBASP firmware.
The Hardware-Modification is quite simple: It's a conection between the AIN1-Pin and the unused NC-Pin.
Bild 1: The new Connection between AIN1/PD7 and NC
I've used a MX-USBASP 3.0 Board:
Bild 2: Hardware-Modification of an MX-USBASP
Software
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Projekt-Download, Git-Repository
You can find the Firmware changes in the feature/USBASP-Branch of the Git-Repository:
Bild 3: Modfied USBASP with 35Mhz R/C-Receiver