Hacking the UMX part 3

Continued from Hacking the UMX part 2…

lithium battery

* Next I’m going to hook up the power supply ( a 2S 7.4V 18 mAh 20C Lithium Polymer Battery) to the ESC (Electronic Speed Controller). I’m going to solder 3 breakout pins to the power leads coming from the ESC so that is easier to plug and/or unplug the power supply to the ESC.

ESC diagram

* I soldered new connections for the power from the battery to the ESC, and soldered connectors for the hookup to the motor

solder power line

* Tested the connections I built against the Arduino UNO on the breadboard – it is working – a value of 30 appears to be the low throttle setting – max is 180.

* Now need to re-attach the prop and confirm it is turning the right direction before I continue.

* It is not turning the proper direction – I need to switch 2 wires leading to the ESC – will switch the outside wires.

* Got that wired up – tested the prop to full speed and not getting enough thrust to lift the UMX – what the hell? Examined the setup, the code, everything looks okay – looked at the prop – I had screwed it back on upside down after dis-assembly. So for the record the motor and prop combination doesn’t work well if the prop is bolted on upside down – fixed now and working – UMX lifts off at throttle setting of 130 (scale from 30 to 180 full throttle).

servo wiring

* Now wiring all 4 servos into one power and ground cord – lots of fiddling and detail work to get all the wires where I need them to be. Still working on this, taken several hours to get the servos connected properly – huge pain. I was trying to do this individually but instead did the power and ground cords in series, they are all plugged into a single wire for power and a single for ground – this is working.

* Each servo needs a separate signal wire – so I soldered the 4 individual leads and am now testing each one to confirm they work. Dorsal – works, Starboard – working, Port – works, and Ventral – working.

* Now I’m going to test if the servos can run from the arduino’s power board, and not a separate power source. In the flying version the lithium battery will send power to the ESC, the ESC sends power to the flight motor and the arduino board. If I can power the servos from the Arduino it will simplify the setup.

* This is working – now need to begin connections to the actual Arduino Pro Mini I’m going to use for flight tests.

Pro Mini solder

* Soldered pin outs for the servo connections, plus for the power supply and ground for the servos.

* Connect servos control and power/ground leads to Arduino Pro Mini and test … working.

connected Mini Pro

* Now confirm Arduino Pro Mini can control the main motor as it is currently connected – done.

* Now the tough part – the existing code I have outputs roll,pitch,yaw data from the ArduIMU over the serial port. I can’t receive this data over serial with my main Pro Mini board and have my Mac USB connected at the same time – which will make it very, very hard to debug. To get around this I’m going to use IC2 to send data from the ArduIMU to the Pro Mini. This is working – I can send data from one Arduino to another without using the serial port.

* Now modify the AruIMU code to send the roll, pitch, and yaw data via IC2 – this is working.

This entry was posted in Arduino, Hardware, Robotics, Software, UAV and tagged , , , . Bookmark the permalink.

One Response to Hacking the UMX part 3

  1. Pingback: Hacking the UMX part 4 | Botlets

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