Re: [Paparazzi-devel] Hello

[antoine . drouin]

Hi folks

Quoting John Edgecombe <address@hidden>:

> Both projects now use essentially the same inertial units,
> and paparazzi has ported autopilot software. The big difference seems to be
> in the control boards, with paparazzi using an ATmega 128 and an ATmega 8,
> while the autopilot control board uses an ATmega 163 which Atmel has phased
> out.

I think ATmega 16 is pin for pin compatible and can be used as replacement.

> The version 3 board is still in the future. I have done just enough
> hardware to be uncomfortable with it. There is a real art to picking
> compatable parts and getting them to work together without glitches. Board
> design is another area where prototyping costs can eat you alive if things
> don't work as planned. I can solder most anything except SMD and flat packs.
> I have never tried reflow, and I don't want to invest in those tools.

The paparazzi board is all SMDs. I soldered it with a normal iron using the
'put_a_lot_of_solder/remove_excess_with_braid" method. The PCBs are
"kitchenmade" (no metalized hole). I'll put a photo on the paparazzi page.

> While I have installed the freeware version of Eagle, I cannot look at any
> of the paparazzi boards except the main board schematic, and even that one
> produces an illegal data error in Eagle. I suspect that the boards have gone
> beyond 2 layers and are no longer viewable in the freeware version.

The paparazzi board has 2 layers. I designed it with the freeware version of
eagle. It is strange that you cannot open it: which version of eagle are you
using ? I am using 4.09-linux

The board has a few more componnents: a switching 5V regulator, a linear 3.3v
regulator, a flat cable connector for the ublox SAM GPS, a cmx469
modem. It doesn't have the frequency to voltage converter for the tacho.

That said, there is only one prototype of the paparazzi board and it only has
completed two flights. There are also numerous "details" that i want to change
in future revision (use fewer crystal- the current board has 3 - integrate IMU
in controller board - he current connector is as big as a gyro..- move the
connectors, etc...). I want to make a new revision by october.

If you want to build a Parazzi board, go on, I'll be pleased to get feedback,
but be warned that it is very new and barely tested. 

If you don't need the extra components, or the extra cpu, i think it's way safer
to go with an autopilot board.

> Annonymous said, "The code will expand to fill the available space." So, at
> the moment, I favor the bigger is better approach of paparazzi, but building
> one is not as simple as the autopilot kit.

We have alot of space and processing power available in the 16MHz-mega128.
We want to use it to try to implement basic navigation.
 
Regards

Antoine