MultiWii

Hello all,

I'm just finishing to build my X quadcopter, it will be a 600 mm wheelbase unit, with 4 Aeolian 2830 motors and 10x4.5 propellers.
I cnc'd all the parts from 3mm polycaronate sheets, and I'm finishing (hope this night) to put all the mechanical parts together.
Next step will be to install the electronic board (Crius Lite, as told in the title), and wire everything together.
So, I read the forum, but still have few doubts about the board:

1. Which kind of Arduino would you define in Arduino IDE? I'm now using the "Arduino Duemilanove w/ Atmega328", is this the correct one?

2. From the multiwii website, in the "connecting elements" page, I can see the "QuadricopterX configuration for atmega328", which I think is the correct one for me; so I have to connect the four motors to the D3, D10, D11 and D9 pins on the Crius board, right?

3. My 6 channel transmitter/receiver (FlySky FS-CT6B) should have a PPM sum channel; could I use it with the Crius board and Multiwii firmware? How?
I know I could use a PPM signal on the D2 pin on an Arduino, but Crius Lite does not have such a pin.
On which phisical atmega pin is D2 connected on the arduino?
If not already provided, I would like a #define for the PPM channel also for the Crius board already in firmware (so I don't have to manually modify the code on every revision).

4. The transmitter is set for mode 2; is there anybody that can help me on the right PPM sum sequence for such a transmitter?
I mean, in "config.h" there are few lines of code defining the order of signals on PPM pulse train, which is the right for my transmitter?

5. The most important question: is there anybody here with a schematic of the Crius Lite Board? Or do I have to decode on my own?
I can reverse engineer it easily, but this process will be long.

Thank you everybody for the help.

Ciao,
Giovanni

PS: tonight I will show you my beast, after I finished to mount it together.

Hello Giovanni -

I have a little quad with an integrated Crius SE board.
I defined mine as "Arduino Duemilanove w/ Atmega328". Running in PPM mode, the PPM output from my Rx is connected to "throttle" pins on the controller. You have to uncomment the #DEFINE statements for the Crius Lite and PPM mode, 400Hz I2C, Enable Internal I2C Pullups and whatever else you need in MultiWii. The #define statement for PPM mode allows you to set the correct channel order for the stream coming from your Tx.

This might help, especially the document in the first post.
http://www.rcgroups.com/forums/showthread.php?t=1551599

Regards,
- Felix

Hello Felix,

Thank you very much for your answer, it helped me soooo much.
You solved much of my doubts, and the guide you referred to is exactly what I needed, I printed it and tonight I will try it.
Thank you very much again.

Ciao,
Giovanni

Hello all,

Yesterday night I put togheter all the stuffs, connected everything and setup the Crius board as explained in the guide linked by Felix.
Unfortunately I didn't took any picture, I will tonight.

I tried to fly it, but it can't move from the ground...

I'm afraid it is too heavy, it weights 980 gr. with everything included (even the battery), and uses 4 1000KV motors with 10x4.5 propellers.
xCopterCalc (here: http://www.ecalc.ch/xcoptercalc_e.htm) actually says I'm quite heavy, but I should be able at least to lift it from the ground...

However, I already ordered few 12x4.5 propellers, togheter with a 3000mA 3S battery.
One of those solutions should solve the problem.

My doubt is the transmitter: I'm using a cheap FlySky FS-CT6B 6ch transmitter.
I can connect to it via serial and modify its behaviour with T6config or DigitalRadio software.

The problem is that the throttle channel, even at its maximum extension, it outputs a signal from 1100 ms to 1900ms, and I cannot extend it further.
I know MultiWii firmware expects 2000ms as maximum throttle signal, so maybe I'm not giving the full throttle to the motors.

Do you know where should I modify the firmware to lower the upper limit on the throttle, in manner to use a reduced range and reach 100% output power at, let's say, 1800/1900ms?

Or, do you have any idea on how to extend the ranga on the transmitter? I really don't know very much the t6config software nor the transmitter itself, so any help will be appreciated.

Thank you in advance.

Ciao,
Giovanni