See also: NaviCtrl, MKGPS, MK3MagAufbau

The compass is already integrated into the NC v2.0 - so the MK3Mag is not needed there

MK3Mag

This is a 3-axis magnetic field sensor. Using the current attitude data it forms a tilt compensated compass. The MK3Mag can be used on its own, together with the Flight Ctrl to stabilise yaw control or in combination with the NaviCtrl. The MK3Mag is supported by the FlightCtrl from software version 0.69K upwards.

Instruction for MK3Mag for self assembly (Green PCB’s)... see here MK3MagAufbau

General Points

For use of the MK3Mag it is essential that the distance between compass and Buzzer minimum 10cm. It is best to mount the buzzer on the outer end of one of the frame arms.

The highest Interfering Magnetic field is generated by: Buzzer, Motors, Power Cables and Metal Parts (in approx. this order).

If problems with the MK3Mag are only noticable at higher throttle, it is likely that the interfering magnetic field is generated by power lines. Ideally the individual DC-lines should have very few bends and Plus/Minus should be routed parallel as their magnetic fields are then compensated by each other (Tips and Video).

http://www.mikrokopter.com/files/KompassDreht.wmv

Connection without NaviControl

Usually the MK3Mag is used on a NaviControl. In case you don't want the GPS-features, you can connect the Mk3Mag directly onto the FC.

Attach (solder) the 10 pole pin row onto the SIDE of the MK3Mag and connect to the FlightCtrl using a 1:1 Ribbon Cable. To see the FC and Compass together on the Kopter tool, press a Pin Header (Reichelt Electronics: PFL10SK) onto the cable.

• Instalment direction: Processor pointing up and outer pin row pointing towards the 10 pole pin row on the FlightCtrl

Special attention should be taken to ensure that the MK3Mag is Level (i.e.: parallel towards the FC). An angle of 5° for example would have the effect of an error of >5°.

connection to the NaviCtrl

To connect the MK3Mag to the NaviControl, a 10-pin connector must be installed:

Installation: Use two plastic screws to fasten the MK3mag and avoid contact loss. In case of a bad contact, the GPS navigation could stop or the MikroKopter could fly into the wrong direction. Never use screws made of material that can become magnetic. When this screw becomes magnetic due to the engines, the compas function will get an offset, you will see this as a rotating Mikrokopter, directly after lift-off.

In case that the pins must be replaced:

Trim the Yaw of the RC-Transmitter to Zero

Attention: Yaw must be zero in case of using the compass.

You can check these values in the Koptertool

Calibration

Calibration of the compass

Important: When first operated, the MK3Mag needs to be correctly calibrated! Otherwise the NaviBoard will show you "Err:6 bad compass value".

Now it is (since Version FC:0.84) very easy to calibrate the compass with a "clicking sound" .
This method has the advantage that you doesn't have to hold the Kopter "perfect" horizontally.

Calibration:

1. Step 1: Initiate compass calibration => (Nick down + throttle up + yaw left) The Kopter will beep 1x.
   

2. Step 2: start calibration => pull down the nick-stick once (The Kopter will beep 2x and the clicking starts ).
   

   1. The Kopter shows with the front (Arrow of the FlightCtrl) to south or north.

   2. Turn the MikroKopter a few times in direction of the nick axis until the Summer stops clicking.

   3. Then rotate the copter 90 °. The clicking starts again (Arrow of the FlightCtrl shows to the left or right).

   4. Now turn the MikroKopter a few times in direction of the roll axis until the Summer stops clicking.

3. Step 3: Pull down the nick-stick once The Kopter will beep 3x.

   1. Now you can rotate the Kopter 90° back, but this is not required . You can calibrate the Z-axis in the direction of the nick or roll axis.

4. Step 4: Pull down the nick-stick once The Kopter will beep 4x.

   1. Now turn the MikroKopter a few times until the Summer stops clicking.

5. Save and close the calibration: Pull down the nick-stick once. The Kopter will beep 2x.

Videos

(German version)

(English version)

If the calibarion fails (compass still reports "invalid compass value"), you can take a look here: MagnetError

The process also works in older firmware versions, but then without the clicking sound.

Note: if you use the MK3Mag directly on the FC, it will not make the clicking sound. This calibration method will work nevertheless.

MK3Mag and MK-Tool

To activate the Compass use the Kopter tool (connected to FC) and under Settings->Configuration place a tick on Kompass (Compass).

The KopterTool can also be used to verify the Calibration. To do this set the scope to display the values: KompassValue, Ersatzkompass and MK3MagCalState and turn the Kopter slowly. The angle change should be displayed proportional to the rotation of the Mikrokopter.

A Digital Compass value is also available in the LC-Display under [2] (See Picture)

Circuit Diagram

Assembly Scheme

A detailed assemebly instruction (currently in German) can be found here hier.

Italic displayed parts are on the lower side

Installing new software

On preassembled (red) boards, the bootloader is already programmed and doesn't have to be updated.

Showing the actual firmware-version

Switch to MK3Mag in the KopterTool

Attention: if the actual firmware is already V0.23a, please do not perform a further update. There is no update since 02.2010.

In the NaviControl V2.0 you can't switch the communication to the internal compass.

Flashing new firmware through the NaviControl

• Remove jumper of the MKUSB

• The MK3Mag remains on the NaviControl.

• The MKUSB is connected to the NC

• Switch on the MikroKopter

• Click to 'Firmware Update and Terminal' in the KopterTool to open the terminal window

• Selcet actual HEX-File for the MK3Mag
• Programming starts. At the end the MK3Mag shows its actual version

Firmware flashing without NaviControl

• Remove Jumper on the MKUSB
• Connect the MK3Mag on the connector on the side of the MKUSB.
• Use the connector on the lower side of the MK3Mag (the same you would connect to the NC)

• Click to 'Firmware Update and Terminal' in the KopterTool to open the terminal window

• Select actual HEX-File for the MK3Mag
• Install the Jumper into the MKUSB to supply the MK3Mag
• Programming starts. At the end the MK3Mag shows its actual version

Firmware (SVN)

Sources and .hex-files can be found here:

Link to SVN

KategorieHardware KategorieEnglish