Tag Archives: connecting

Power distribution board vs. Cable harness

When I started with the Multicopters in the late 2012, I used cable harness/power breakout cable  for the power distribution from the battery to the ESCs in my first quadrocopter. Until last month I always used my self-made cable harness in my copters. There were no problems during the flights and everything was just great.

Last month I decided to buy one from these so called power distribution boards. Just because of the weight and it looks a bit better when there are not so many cables. My goal was to safe some grams and optimize the overall weight of my SG Adventure quadcopter. It is a small quad and every gram matters.

Soldering was a bit tricky, because I left the ESCs mounted on the quad and I am not so good at soldering. In general there is no difference, but it looks better for me now. The quadcopter flies great, as it was with the cable harness.

How many grams do I saved?

Cable harness and the 3.5mm gold connectors, that I cut from the ESCs wires: 28g + 12g = 40g.       Power distribution board + 4mm gold connectors to the battery + some tin-alloy: 3.5g + 10g = about 15g. So I saved about 25g, which is not much, but for small copters every saved gram means more flight time.

Another cool feature on this flyingfolk board is, that it is possible to solder other low current components such as LED or Voltage-Sensor on the corners.


Connecting Mission Planner over Bluetooth

I am using the MultiWii and MegaPirate AIO board (Crius clone) on my quadcopter since a few weeks. I had also a Bluetooth Module HC-05, which I bought for some Arduino projects. I wanted to connect the Mission Planner with my QuadCopter over Bluetooth using this module. I tried and followed the guides on Internet, but without success. Even the tip with first clicking the “Connect” button in Mission Planner and then powering on the HC-05 Bluetooth module didn’t helped me.

I did all the things right: Changed the default baud rate of my HC-05 with AT-Commands to 115200. In my APM_Config.h defined the baud rate of Serial0 to 115200. Connected and paired it with my PC. In Mission Planner chose the right COM port and the right baud rate of 115200. Without success… every time I tried to connect, I became “Getting Params” and then a “Connect failed” in Mission Planner.


Today I became another tip on a Bulgarian Hobby Forum: Not to use the Serial0 port, but the Serial3 port of my flight board. I defined the Serial3 port baud rate in my APM_Config.h, flashed it and connected the Bluetooth module with the Serial3 pins and for the GND and 5V with the Pins for the Camera Shutter.


Then I used the tip with first clicking the “Connect” button and connecting the power to the module, when the Mavlink Window appear on the screen. Few seconds and it WORKED. Problem solved. I still don’t know, why it don’t work over Serial0, but I am happy, that I can use my HC-05 Bluetooth with Mission Planner. So thanks again to the guy, that gave me this tip!

Update 21.04.2014: Here you can read on how to connect with the App DroidPlanner 2 over Bluetooth.

Update 01.05.2014: Mission Planner was updated to version 1.3.1. Since then you don’t need the trick with first clicking “connect” and then actually connecting the Bluetooth module anymore.

Building my Quadcopter

In my last article I described which parts do we need, so we can build a 300$ quadcopter. I will try to explain the building process as simple as possible. In this article I would not mention how to optimize your copter by eliminating vibrations, balancing props or tuning the PID settings of your flight board. In my opinion a beginner should start with the basics and then learn new things step by step. So let´s get started.

In my very first quadcopter I used the X525 frame from HobbyKing, but later I created my own frame. This one is made of plywood on a CNC-machine. If you bought the X525 frame you should start with assembling it first. An assembly manual is included in the package with it. When you are ready with this step, then you should mount the 4 motors on it, without any attached propellers. The Turnigy D2830-11 motors come with a mounting adapter, screws and prop-adapters. On the X525 you don’t need the mounting adapters and can easily mount the motors direct on the glass fiber motor mounts. On the picture below you can see the motor on my actual plywood frame.


On the second picture you can see it from the bottom side. Here we come to the next step: connecting the four ESCs with the motors. Every ESC has on the one side 3 cables (red, black and yellow) and on the other side 2 cables (red and black). There is also a tiny cable which ends with a male-plug.


Please note that the ESC on the picture has no connectors on its cables. As I mentioned in my first article you can buy these 3.5mm gold connectors and solder them on the ESC. By two of the ESCs (either Nr.1 and Nr.3, or Nr. 2 and Nr. 4) you should reverse the red and yellow cables. This is because we want two of the motors to spin in counter-clock direction. I tried to illustrate this on the picture below.


Propellers: The right one spins in clock direction, the left one in counter-clock direction. I had the problem as a beginner that, I didn’t mount the right prop on the right motor and so my quad either not take off or flipped. So take you time and do it right.

Next you should connect these tiny cables from each ESC to your flight board. If you bought the KK 2.0 board or the newer one KK 2.1, you can check the next picture on how to do it right. The cable from ESC 1 (front left) comes on pin1, ESC 2 (front right) comes on pin2, ESC3 (bottom right) comes on pin3 and ESC 4 (bottom left) comes on pin4. The tiny-cables must have this order from left to right: yellow, red, brown.

Then you should connect the other cables of each ESC to the battery. All 4 red cables to the red cable on the battery and all 4 black cables to the black cable on the battery. There are three ways to accomplish that: You have bought a power distribution board and solder the cables on that one. Or you bought a power breakout cable…or you make yourself one.


Once you have done this, you should connect the receiver (RX) to the board. On the KK2.0 and KK2.1 the receiver-pins are on the left side. You need at least a 4-Channel-RX for a quadcopter and if you are using the KK board it is good to have a 6CH or more. When connecting the cables to the board, beware: from right to left: yellow, red, brown. (Brown for ground, red for VCC and yellow for signal cable). If you want to test, if all the cables are right connected go to the “Receiver Screen” on your KK board and do this: Move the sticks on your Transmitter (TX) and see if it is right indicated on the screen. Probably you should also reverse some of the channels on your TX to do it working properly.

So if everything is connected the right way you can try to make your first fly. To do this you need to “ARM” your flight board. Move the Throttle-Stick on your transmitter down and right and hold it for a few seconds and then release it. In this case the board should indicate “Armed”. Now move your throttle stick very slowly so the motors start spinning. Then move it again very carefully and observe the behavior of the copter. If you have problems such as not taking off or flipping, as said you had mounted the props wrong or connected the yellow and red cables of the ESCs wrong. If so, “disarm” your copter by moving the throttle stick down and left for a few seconds, so the KK board shows the “Safe” screen. Then try to fix the problem and try again. If you cant solve the problem, you can either search on google or comment here.

At the end: Beware, these machines are not toys, they have a lot of power and can heart people. Be careful when flying and have fun. If you find my article useful, please click on the buttons below to share it. Thanks!

02.06.2014 Update: Here you can see my new build with the “SG Adventure” carbon frame.