RE: [Paparazzi-devel] Protocol for the downlink

[Cédric Marzer]

Interfacing airside should be interesting...have you considered going
down the I2C/SPI route rather than tapping the serial line?

I guess tapping the serial line is easier as a start. It would be possible
to avoid to use a second microcontroller by just connecting a MAX dedicated
OSD chip to the spi, but for now I will be using the board with an LPC and a
MAX that I already have.
I might develop later a graphical OSD that uses either the LCP2148 or a
PIC32 (cheaper). 
In this case you need a dedicated microcontroller because the timing is
important, but you don't need the relatively expensive MAX chip.