https://github.com/mdda/nodebots-sg-2015
International Nodebots Day in Singapore (2015)
https://github.com/mdda/nodebots-sg-2015
Last synced: 21 days ago
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International Nodebots Day in Singapore (2015)
- Host: GitHub
- URL: https://github.com/mdda/nodebots-sg-2015
- Owner: mdda
- License: mit
- Created: 2015-07-23T15:38:44.000Z (almost 11 years ago)
- Default Branch: master
- Last Pushed: 2015-08-29T16:29:14.000Z (almost 11 years ago)
- Last Synced: 2025-12-28T19:05:36.241Z (6 months ago)
- Language: C++
- Size: 414 KB
- Stars: 3
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# International Nodebots Day in Singapore (2015)
This is a repo that represents what I did for the hacking day
held in Singapore at the IDA Labs.
### BeagleBoneBlack (notes only - not used on the day)
The initial two pieces concern the BeagleBoneBlack board that
I bought ages ago, and wanted to see whether could be used for
NodeBots experiments.
Short answer : Yes, but currently Fedora
does not easily package up the same 'ethernet over USB' boot mode
that the default Angstrom distro provides.
Since I couldn't make Fedora boot to my satisfaction, that meant it
was game-over for the BeagleBoneBlack (for now).
### Gimbal - Rescued from crash and made NodeBot-able
The gimbal is a very attractive (to roboticists) piece of hardware that
was originally designed to stabilised a camera mounted beneath a quadcopter.
However, since the quadcopter in question has self-disassembled : It
was time to experiment with the gimbal board as (potentially)
an Arduino compatible-host for for Johnny-Five nodebot control.
One eye-catching thing is that the entire assembly (two brushless motors,
gimbal controller board, 3-axis sensor, CNCed aluminium hardware and
on-board USB/serial interface) was pretty cheap - here's what I found online
(though I bought the unit around a year ago) :
* [less than **$60** from AliExpress (original source)](http://www.aliexpress.com/item/2-axis-BGC-Brushless-Camera-Gimbal-GoPro3-Controller-PTZ-aluminum-Full-set-of-parts/1585412479.html)
* Or very similar setups :
* [for ~$47](http://www.aliexpress.com/item/2-Axis-DIY-CNC-Metal-Camera-Brushless-Gimbal-Mount-for-DJI-Phantom-1-2-Walkera-X350/32266077761.html)
* [for ~$45](http://www.aliexpress.com/item/2208-Shaft-Gimbal-Brushless-Motor-80KV-3-12-MOS-Brushless-Gimbal-Controller-Driver-Shock-absorbing-CNC/32259711679.html)
* And the individual components:
* [Controller board](http://www.aliexpress.com/item/2-Axis-Brushless-Gimbal-Controller-board-containing-IMU-can-use-Germany-Russia-Russian-firmware-BGC/1913360790.html)
* [Gimbal hardware](http://www.aliexpress.com/item/160g-RTF-DJI-Phantom-Gopro-2-3-CNC-Brushless-Camera-Gimbal-not-including-motors-1-brushless/32383003272.html)
* [High torque brushless motors](http://www.aliexpress.com/item/Brushless-Gimbal-Motor-2208-KV80-for-Gopro-3-Brushless-Camera-Mount-Gimbal/2024123654.html) - NB: These are
different from regular brushless motors (that you would use to spin the propellers, for instance) because these are wound with very thin wire
(and 70T refers to 70 turns of wire, for instance). This means that the motors draw less current, which is better for being under constant power (heat-wise, at minimum). So,
you need to specify 'gimbal' in any search for brushless motors to ensure that you get the right kind of specifications.
Fortunately, it became apparent from its documentation and source code
that the 'Martinez-compatible' Gimbal board is equivalent to an Arduino MegaPro,
and I spent the afternoon figuring out the pin assignments, etc.
Key features of the write-up:
* Identified board (and LED pin) so that the gimbal unit can run Blink
using the ```ino``` command-line utility (NB: wanted to do this due to heavy-IDE allergy)
* This proved its programmability in C, and upload functionality via USB
* Create ```fermata``` firmware for the board (small modification required to avoid IDE)
* Write NodeBot code to (a) blink and (b) control the motors
* The brushless motors are controlled by sending 3 different PWM signals (one to each brushless motor wire),
which in turn can control the motor position fractionally between individual magnet poles
If anyone needs help enhancing the code (which I'll continue to add to), please let me know.
Also, I'm pretty sure that any gimbal board that you can get source code for
(i.e. don't buy a board unless source is available) would be NodeBot-able
and therefore a neat, integrated platform of all sorts of projects (and, I guess,
camera stabilisation, if you need that motivation too).