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RotorHazard FPV Race Timer

 

The RotorHazard FPV Race Timer is an open-source multi-node timing system that uses the video signals from FPV vehicles to determine when they cross the start/finish line.  The heart of the system is a Raspberry Pi, and each node has a dedicated Arduino Nano and RX5808 module.

The Raspberry Pi runs the Raspbian OS (with desktop), and the RotorHazard system uses a server component written in Python.  The stand-alone-server version uses the 'Flask' library to serve up web pages to a computer or hand-held device, via a network connection.  An SQL database is used to store settings (via the 'flask_sqlalchemy' extension), and the 'gevent' library is used to handle asynchronous events and threading.  The web pages that are served up use the Javascript 'Articulate.js' library to generate voice prompts.

Check out RotorHazard on GitHub, here:  https://github.com/RotorHazard/RotorHazard

See here for a gallery of pics of my timer hardware.

Major Features

RotorHazard can be run with minimal hardware -- or even no hardware at all!
To run RotorHazard on your PC, see the project docs on Other Operating Systems.
See the USB nodes doc for info on an easy-to-build single node version of RotorHazard.
If no hardware nodes are connected, RotorHazard will operate using simulated (mock) nodes. In this mode the web-GUI interface may be explored and tested.

Discuss RotorHazard on Facebook: https://www.facebook.com/groups/rotorhazard

To report bugs or request features, please post a GitHub issue here.

The RotorHazard project is lead by Michael @ HazardCreative and myself (ET).



Here's a wireless setup for the race timer that I've found works well. The router is a bit to the side and behind the (shielded) timer box to help prevent RF interference. I have the router configured to use 5.2GHz (channel 40), so it doesn't interfere with our video signals. When I tried running the router on 2.4G I found that our RC transmitters raised major havoc with the router data.

The power source is a fancy camping battery that one of the guys in flying group kindly donated, but lipo batteries could work just as well. The timer box is connected to the router via a short ethernet cable. The link to the computer (showing the RotorHazard web/GUI interface) is over wi-fi.

The router is an Asus RT-N66, running open source firmware (
Tomato by Shibby, K26RT-N / build5x-140-MultiWAN / Asus RT-N66u 64k / tomato-K26USB-1.28.RT-N5x-MIPSR2-140-AIO-64K.zip, local copy, how-to).

The router needs 19V input -- for my setup I'm able to use the AC adapter, but if I needed to step the supply voltage up to 19V I would use a Pololu regulator like the S18V20AHV.

 



Notes on building using the
original Delta5 PCBs, as shown in the gallery of pics:

1. There are three cuts to PCB traces so that each of the Arduinos can be individually powered, and disconnected from power by pulling the nearby jumper.  This makes it so that, if the jumper is pulled, only the single Arduino receives power when updating its firmware using its USB connector.  The trace cuts are visible in this pic and this pic.

2. The +5V supply trace to each of the Arduinos was connected to VIN (the input of the onboard 5V regulator), whereas they should be connected to the actual 5V supply pads, so the red-wire jumpers make that connection.  Whether or not the +5V still connects to VIN doesn't make much of a difference.

3. The black-wire jumpers connect ground on the PCBs to both ground pads on the Arduinos instead of just one of them, but the board will run the same either way.

4. In some of the pics there are two diodes and a resistor tied to the I2C bus lines, but they are not necessary.

Part Links:

Arduino Nano V3.0 16M 5V ATmega328P module
https://www.ebay.com/sch/i.html?_nkw=Arduino+Nano+V3.0+16M+5V+ATmega328P

Boscam 5.8G Module RX5808
https://www.banggood.com/search/rx5808-module.html
https://www.ebay.com/sch/i.html?_nkw=rx5808+module

Pololu 5V, 2.5A Step-Down Voltage Regulator D24V25F5
https://www.pololu.com/product/2850

Pololu 3.3V, 2.5A Step-Down Voltage Regulator D24V25F3
https://www.pololu.com/product/2849




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ET Heli