Tag Archives: quadcopter

HobbyKing AIO – GPS and Bluetooth

I started by connecting the HobbyKing AIO board to the GPS that I bought from HobbyKing for $35 and to the HC-05 Bluetooth module. This allows me to configure the AIO via BT.

IMG_8400

The connections are as follows:

GPS to AIO board

The UBlox Neo-7M GPS comes with a cable that has 2 mini-molex connectors, one with 4 pins and one with 5 pins.

gps connector

Some changes must be made to these connections in order to fit them to the AIO board. Moving the cables between pins is simple – lift the flap that holds the cable inside the connector and pull the cable out. See the photo below.

IMG_8401

The changes to cabling are as follows:

4-pin connector

The 4 pin connector is connected to the i2C connector on the AIO.

It should have the following cable connected to it, from top (leftmost) to bottom:

  1. SCL – moved from pin 2
  2. SDA – moved from pin 3
  3. VCC – moved from the 5-pin connector
  4. GND – moved from the 5-pin connector

5-pin connector

The TX and RX cables from the 5-pin connector must be connected to RX2 and TX2 on the AIO board respectively. So I replaced the 5-pin connector with a 6-pin connector that I had from the AIO package and connected the TX and RX cables at the right slots.

AIO board to HC-05 BT module

The BT module connects to the FTDI port on the AIO as follows:

  1. AIO GND  —> HC-05 GND
  2. AIO VCC   —> HC-05 5V
  3. AIO – RX   —> HC-05 TX
  4. AIO TX is connected to HC-05 RC via a voltage divider in order to protect the HC-05. The HC-05 uses 3.3V while the output of the AIO board may be 5V. The following photo of a crumpled piece of paper shows the two resistors that form the voltage divider.

IMG_8402

AIO external power

The AIO receives 5V power from an external source on the GND and VCC pins.

 

 

Flying by cellular – Project Plan

After a long break while working for a start-up company I’m returning to my main technological hobby – quadcopters.

This time I’m building a quadcopter based on the HobbyKing AIO board:

IMG_8380

My main goal is to control the UAS (unmanned aerial system) over the cellular network. This means that commands will be sent to the UAS over the cellular network and the video feed from the UAS to the operator’s console (a computer, or a cheap PS3 joystick) will also be transmitted over the cellular network.

There is nothing new in this approach by itself and people all over the net are doing it by putting a $50 Raspberry Pi running Linux on the UAS. My angle on this would be to try and achieve this goal with cheap hardware.

My development plan is as follows:

  1. Build a good and stable UAS and get it to fly with the HK AIO controller – using the HK firmware
  2. Compile the firmware from sources, configure it and get it to fly
  3. Transmit commands over the cellular network
  4. Transmit the video feed back over the cellular network

Fixing a broken HJ-450 arm

As I reported in a previous post (an expensive evening), I broke the arm of Misha’s HJ-450 frame.

I decided to glue it back together with epoxy glue. I don’t remember the brand of the glue which I use, but here is a photo:

Epoxy glue

Epoxy glue

I covered the broken edges in a large amount of glue and let it dry for a day:

Glued HJ-450 arm

Glued HJ-450 arm

And … very surprisingly … it held out so far in about 20 landings, some of them not very gentle.