This project was started in , electronics and control loops. Because I always need a cool project to learn new things, it was clear that something that can fly had to be built.
The project started as a "tricopter-only" project, but as I wanted to build smaller vehicles with more payload capacity, I decided to make some quadrotor, hexacopter and Y6 hexacopter firmwares too. My main interest is to build very small MAVs that fly as good as larger ones (or even better) and that can be controlled by wireless video link. I also experimented with autonomous flight in GPS-denied areas (video), and with GPS assisted autonomous hover (video).
-- William

Contact: Shrediquette @ g m x . d e --- All content published under CC Attribution-Noncommercial-Share Alike 3.0 Germany

GUI almost done...

The GUI for my tricopter is almost finished. Watch a screen capture video here. It's working very fine and it is pretty handy.

 What needs to be added is a possibility to flash new firmware to the tricopter. I would like to include avrdude in my GUI, but I still need to do some test with avrdude, Arduino bootloaders & RS232 cables... The GUI will be released when it is finished.
The Arduino pro mini m168 is now filled to 85%. I will change over to an Arduino pro mini m328 so that I'll never run out of space.
It seems as if I am going to build an extra tricopter with the ESC's from That is a good opportunity to test everything again, making sure that building a Shrediquette DLX doesn't cause any problems.

Edit: Today I sucessfully flashed my m168 and my new m328 via RS232 + bootloader + avrdude! I also managed to run avrdude hidden inside my GUI (so you don't have to enter any parameters, everything is done automatically with one single button press!). I will soon write an extensive tutorial on how to build a Shrediquette and how to set all parameters etc....


  1. Good job!! william
    I think Tricopter Gui is simple and useful.
    Thanks to share your tricopter all stuff^^

  2. You're great !

  3. Waiting on the edge of my seat for the GUI!!!! can't wait!!!

  4. This is brilliant!!!

    I have built a Mikrokopter but this seems much less complicated and is programmed in BASCOM that I understand!!
    I thought I read somewhere the back motor is controlled by a servo to change its position (I can't find where I read that now!) is that correct?
    Do you use standard ESC's or I2C ones like the MK?
    You have used an Arduino - why not put a 328 or 168 direct onto the pcb?

    regards Peter

  5. Hello Peter,
    yes, I am using a servo to tilt the motor at the back:
    I am using I2C ESCs (actually standard ones that I modified, but the "Holger-Regler" will also work). I am using an Arduino, because it comes preprogrammed with a bootloader. That is quite handy for people that do not have Bascom or an ISP-Programmer. With the Arduino, they can simply program the controller using a simple RS232 cable.

  6. Impressive engineering, and beautiful cinematography. Thank you for sharing it with everybody.

    I can understand that using I2C can minimize the number of pins to control ESCs etc. I also read an argument and also counter argument that I2C's fast speed provide advantage. However, considering the inertia of the propeller, I do not see that update rate of the speed control is that critical.

    Can you enlighten us why you use I2C for ESCs and do you thing normal ESC with RC input can be used in your system?


  7. Dear Roberto,
    I also think that I2C is much faster than PWM. But, there are also Quadrocopters that work really good with PWM ESCs. You're right that the inertia of propellers should make the whole system quite slow. But still, even if the "rpm-change" reaction of the motors is slow, there is no reason to make it even slower using PWM. I am planning to make a I2C->PWM converter using three (or even four) mega8's (TQFP package). But I am still looking for a "sponsor" for three standard PWM ESCs so that I can test the converter. Anyone, feel free to borrow me these ESCs, you will get them back when I finished programming the converter.

  8. Thanks feedback William. Couple more questions I have:
    1. How far from the centre of the frame are the motors.
    2. I assume the variable pitch motor is to the rear of the flight direction?
    2. How should the gyros be orientated relative to the flight direction and how are the sensor boards mounted (ie flat)?

    regards Peter

  9. The distance of the individual motors is 37cm. But the copter can be smaller or larger, it doesn't really matter that much.
    "Variable pitch" is a bit misleading. It is fixed pitch, but the motor itself can be rotated. It can be to the front or to the rear, as you wish. Personally, I think it looks better with the motor at the rear. The gyros are orientated to work for roll, nick and yaw. In this image, you can see the sensors:
    The front of the copter would be bottom-left.