The purpose of this project is that I need a lightweight, small, and powerful motor for my flying wings. This type of motor controller is easy to make compared to the previous ATMEL motor controller, because I chose not to have outputs like Overheating, center position, max position etc. This design will only have one output, and that is the PWM signal for the motor. There is no adjustment, since this can be set on most transmitters. 

This motor controller will handle a SPEED400 motor (6V) perfectly with 8 cells (draws about 10 amps with load) . (can be expanded). and do I need to say it is with BEC, and will remove power from motor, BEFORE total loss of control, giving you plenty of time to land the plane.

Since the size of this project was the greatest challenge, I have removed my adjustment button from my design (can be seen on my other controller boards) to make it as small as physically possible.

This means that the range of the chip is hardcoded in the chip, and is therefore not changeable. Therefore to be certain that you will have no problems with using this motor controller, you should have a transmitter that is capable of adjusting its range. 

I have decided to make a new code version available that will have the possibility of a button-less adjustment, thereofr removing the above issue. It is important to state that you will not have to build/buy a new controller to get the new code working, you just download this to the controller directly, without even removing the chip from the PCB - This can be done by yourself *** (if you are a little experienced in programming chips and soldering), or it will of course be possible for me to do it (-:

*** Note for the chip programmer: DO NOT CONNECT YOUR MOTOR TO YOUR CONTROLLER WHILE PROGRAMMING IT, OR YOU CAN GET SERIOUSLY HURT - PIN 7 IS CONNECTED TO THE GATE OF THE FET - RESULTING IN POWER TO THE MOTOR WHILE PROGRAMMING!!! 

Code are available for download that has the direction the normal way, and reversed.

Click on picture to view:     (This is version "BETA 100")

(Testing the software in the ATtiny12 on the mainboard of the "old prototype")

(The finished PCB)

(assembled and ready to rock)

(compared to the "old prototype", and a machbox)

View Schematic of Motor controller

View PCB of Motor controller

Download PCB of Motor controller in PROTEL 2.0 format.

Download .HEX file here

The Fuse bits/Lock bits are not set in code, and are as follows:

• CKSEL 3 = "0"
• CKSEL 2 = "0"
• CKSEL 1 = "1"
• CKSEL 0 = "0"
• BODLEVEL = "0"
• BODEN = "0"
• SPIEN = "0"
• RSTDISB = "1"

0= Programmed / 1 = Unprogrammed

Component placement Front side: 

Observer polarizations of the 3 capacitors 10uF are polarized (should be placed according to above image), and the 0.47 are not polarized (can not be placed wrong).

Component placement Back side:

(Observe this is for 2 FETs. - 4 FETs are quite similar)

Download PCB of Motor controller for 4 FETs

View PCB of Motor controller for 4 FETs

Use it as a switch

Without making any changes to the physical design of the controller it is possible to gat it working as a general purpose RC-switch.

Just download the Switch code located here, and download it to the controller, and you will have a small stick operated switch, that will turn on your lights/ take up your landing gear/ Put glow on your glow plug / open your cargo bay/ drop your mini bombs or whatever you require. I made it to be able to turn my Camera Transmission ( wing cam) on my Flying wing on and off. - If the battery is running low, the camera might suffer from low voltage condition, so I just turn it off.

The Switch code has a build in hysteresis function, so if using the stick on you transmitter, you will not be able to have flickering of the switch signal if you are at mid point. its On or Off (unless you move your stick very quickly back and forth). (some equipment can be damaged by a fast switching power supply).

Bill Of Material - Controller board:

• 1 x (1.0 x 2.5 cm) printed circuit board
• 2 x 10 uF capacitor SMD
• 1 x 0.47 uF capacitor SMD
• 1 x 10 Ohm SMD
• 2 x 1K Ohm SMD
  
• 1 x Micro controller (AVR ATtiny12 - Programmed with motor controller software version "Micro_1 or Switch_1") SMD
• 1 x Low drop voltage regulator 5V/1A (LM2940) SMD
• 2 x IRF7805 SMD (4x Depending on the choice of design)
• 1N5822 (Do not need to be SMD, since it can be placed directly on motor)

If you wish to Order the parts from www.digikey.com, you can use the following orderlist:

* This IRF7455-ND FET has not been tested by me, but it should be like the IRF7805-ND just more powerful (Digikey order number for IRF7805 is IRF7805-ND / HEXFET(N) 30V 13A 8-SOIC)

        (REMEMBER THE 1N5822 or equiv. on motor, or motor controller will not last longer than 20 sec.!!!)

Remember to visit our model airplane club, called SKM. Find their "Landing field" on the web at www.skm-rc.dk.

Email me at - kimfmx@gmail.com