The Quadcopter controller is a flight control board for 4 rotor Aircraft (quadcopters). Its purpose is
to stabilise the aircraft during flight. To do this it takes the signal from the three gyros on the board
(roll, pitch and yaw) and feeds the information into the Integrated Circuit (Atmega IC). This then
processes the information according the software and sends out a control signal to the Electronic
Speed Controllers (ESCs) which are plugged onto the board and also connected to the motors.
Depending upon the signal from the IC the ESCs will either speed up or slow down the motors in
order to establish level flight.
The board also takes a control signal from the Remote Control Receiver (RX) and feeds this into the
IC via the ail, ele, thr and rud pins on the board. After processing this information, the IC will then
send out a signal to the motors (Via the M1 to M4 pins on the board) to speed up or slow down to
achieve controlled flight (up, down, backwards, forwards, left, right, yaw) on the command from
the RC Pilot sent via his Transmitter (TX).
The Quadcopter flight configurations depend on which firmware is loaded onto the chip.
This configuration is Quadcopter (4 Rotor + configuration).
Specs.
IC: Atmega168PA
Gyro: Murata Piezo
Input Voltage: 3.3-5.5V
Signal from Receiver: 1520us (4 channels)
Signal to ESC: 1520us
The Quadcopter controller uses Murata piezo gyros that are less sensitive to vibration than SMD
type gyros, but it is still a good idea to mount the board on a vibration dampening material. The
board must also be mounted with the white arrow facing the direction of forward flight.
When connecting your Remote Control Receiver (RX) you must connect the white signal wire of
the channels (CH1, CH2, CH3 and CH4) from your RX corresponding to the aileron, elevator,
throttle and rudder to the inner pins on the board while the red (VCC) wires are connected to the
center pins, and the black (GND) wires are connected to the pins on the outer edge of your board.
The pins marked M1 to M4 are connected to the 3 pin BEC plug from your ESCs. They follow the
same convention as the RX pins with the white wires connected to the inner pins, the red wires to
the center pins and the black wires to the outer pins. The ESCs and the connected motors are
plugged onto the pins M1 to M4 in the following order depending on flight rotor configuration.
Note also the direction of rotation for each motor. This is achieved by connecting the three ESC
wires to the motors and swapping two of the wires to achieve rotation in the opposite direction.
Setting up the Quadcopter controller
1.Checking transmitter channels:
-Take off the propellers.
-Turn on transmitter and flight controller.
-Set throttle to about 1/4. Motors should start.
-Move pitch (elevator) stick forward. Back motor should speed up. If not, reverse pitch (elevator)
channel.
-Move roll (aileron) stick to the left. Right motor should speed up. If not, reverse roll (aileron)
channel.
-Move yaw (rudder) stick to the left. Front and back motor should speed up. If not, reverse yaw
(rudder) channel.
2. Transmitter throttle adjustment:
- Turn on transmitter and flight controller.
- If led does not turn on and stays on, lower your trim.
- If still no go, you may need to reverse the throttle channel.
- Arm your board by putting the left stick down and to the right for the LED to come on. If this does
not happen, adjust your throttle and yaw trim down and to the right on your transmitter. Make sure
you do not have any mixing switches on your Transmitter enabled.
3. Initial transmitter ATV/servo range settings:
- Pitch (elevator): 50%
- Roll (aileron): 50%
- Yaw (rudder): 100%
4. ESC throttle range:
- Turn yaw pot to zero.
- Turn on transmitter.
- Throttle stick to full.
- Turn on flight controller.
- Wait until the ESCs beep twice after the initial beeps. (Depend on which ESC's)
- Throttle stick to off. ESCs beep.
- Turn off flight controller.
- Restore the yaw pot.
5. Initial Gyro gain pot value is 50%. Increase until it starts to oscillate rapidly, then back off until it
is stable again. Fast forward flight needs lower gain.
Too low gain is recognised by the Quadcopter being hard to control and/or always wanting to tip
over.
6. Checking gyro directions:
- Take off the propellers.
- Turn on transmitter and flight controller.
- Set throttle to about 1/4. Motors should start.
- Tilt Quadcopter forward. Forward motor should speed up. If not, reverse pitch gyro.
- Tilt Quadcopter to the left. Left motor should speed up. If not, reverse roll gyro.
- Turn Quadcopter CW. Front and back motor should speed up. If not, reverse yaw gyro.
7. Reversing gyros:
- Set roll gain pot to zero.
- Turn on flight controller.
- LED flashes rapidly 10 times.
- Move the stick for the gyro you want to reverse.
- LED will blink continually.
- Turn off flight controller.
- If there is more gyros to be reversed, go to step 2, else set roll gain pot back.
8.Final check:
Place the quadcopter on the ground, stand back a safe distance and slowly advance to about 1/2
throttle. Hold it steady when you start increasing the throttle, because the Quadcopter controller
calibrates its gyros when throttle leaves zero, and then the gyros need to be at rest.
If the quadcopter tries to twist away, check propeller and motor directions, gyro placement and trim
settings. A slight twist is OK.
If not, try to twist the quad. It should resist your movements. More gyro gain gives more resistance.
If it starts to oscillate, reduce the gain. You should not need to reduce the gain below 40%.
Note: the correct procedure for taking off from the ground is as following:
1: The quad and its propellers needs to be motionless.
2: Increase the throttle (collective). Just as the throttle leaves zero, gyro calibration is performed.
3: Enjoy! And remember to close the throttle if you lose control. Much less damage.
NOTES: Do not use bigger propellers than you need. Light propellers gives faster response and
more stability. Try to get it to hover at about mid stick (1/3 to 2/3 throttle). Use smaller/bigger
propeller, different motor Kv or more/less Battery cells to achieve that.
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