Orange OpenLRS

[ROVguy]

I'd like to go UHF, but I'm on a serious budget so was thinking of trying the openlrs along with a turnigy 9xr. I can get transmitter, Tx module and 3 Rx's for under £100 which is way cheaper than the EZUhf. Also I use Ardupilot and minimosd so I've no requirement for the ezuhf rssi tracker etc.

Anyone have any thoughts or advice. I'm aware that some programming knowledge may be required, I'm not a big programmer however I have used Arduino, which I believe the openlrs is based on.

[tomg]

I'd recommend going with the OpenLRSng firmware, no programming experience required if you use the "DTF UHF Companion" available here: http://www.dtfuhf.com/ to flash OpenLRSng and configure the Tx and Rx all through an easy to use interface.
Alternatively, you can use Arduino, configuring for Tx or Rx is just editing a single line in the code.
If you google 'OpenLRSng' there are some videos explaining how to flash the firmware using Arduino.

You'll need a 3.3v (not 5v) FTDI USB programmer to flash firmware and adjust the settings - easily found on ebay for under a tenner.

The spectrum analyser for the Chrome browser (linked on page above) works well too.
Decent antennas are essential to get improved range, if you've gone for the Hobbyking set, the antennas aren't upto much at all.

[tomg]

There's also a handy guide here: https://docs.google.com/file/d/0Bx2RG70c36mmQy1oNlZ0aGljRlk/edit?pli=1 which shows how the FTDI connects to the OrangeRx version Tx and Rx

[ROVguy]

Thanks very much for that matey. What antennas do you recommend and where from?

[tomg]

Diamond 771 is meant to be good quality antenna (but is tuned to 433MHz)

I plan on making my own dipole antennas

These vids are worth a watch for DIY:
RCHacker #37 - Basic Antenna Tuning. 433Mhz Inverted Vee.
RCHacker #40 - 100mW OpenLRSng range testing, vee antenna.

If you plan on using the UK legal 459MHz rather than default 433MHz, the length(s) used will be slightly different

or, for pre-made: http://www.firstpersonview.co.uk/antennas/433459mhz/459mhz-uhf-antennas-straight-sma
Some of the guys on this forum were also manufacturing LRS antennas

Here are some of the config options available with OpenLRSng:



OpenLRSng is 10 bit (1024 servo resolution) by default - most other LRS systems are 8 bit (256 servo resolution) AFAIK.
Enable basic telemetry (beep on packet loss)
Customise channels (upto 16 on PPM) vs refresh rate (hz)
Customise hopping channels (number and frequencies)
Customise output mappings (PWM, PPM, RSSI, even output RSSI as servo position)
Customise data rate (refresh rate vs range)
I think there is also Frsky protocol support for transmitters which support this (ER9X firmware?)

[DaveyLC]

That bloke in the video is really creepy looking  :laugh:

[skyscraper]

Finally got around to working on my HK Orange OpenLRS system.

I had some difficulties getting The OpenLRS_NG firmware working using the "configurator". It didnt seem to want to write the USB port on my Linux system, probably because its browser based and dint have permission   Stuff that , I dont like Google Chrome anyway, its probably stuffed with spyware :laugh:.

Anyway I opted to download the source and blow it using Arduino. You just have to make sure to use a 3.3V FTDI chip!
Next problem was that the EEprom wouldnt erase so the  HK firmware installed EEPROM settings were hanging about. I eventually sorted that by writing a little arduino program and loading and running that just to erase the EEPROM. ( I couldnt be fagged to read through all the fuse bits to find out which ones might have solve this using avrdude and had read dire warnings about changing them without great care.)

Next problem was I just couldnt get into the CLI mode. I ended up looking through the Configurator source and noticed a bit about toggling the DTR and RTS lines. I found I had to hold down the Tx Bind button, then meanwhile connect to usb to provide power, then in my serial port terminal, toggle DTR and RTS, set up the port and baud rate and then finally let go the TX button, which finally did the trick, so I managed to set up the system for 459 MHz operation.

I did a quick test and found that it worked... Wahey! My servos were moving in response to stick input at the TX ... Great!

Next problem is what to use as a Transmitter. For my FrSky system, I used a Futabe 6EXA Tx. Nice but they are getting right pricey on ebay and anyway I got fed up with hanging electronics somewhere in the plastic case.

I had an old 27 MHz Futabe Challenger 4 Channel system ( 25 years old?)  and decided to remove the gimbales.

So far I have the gimbals mounted on a piece of 4 mm Ply, which will be the front of the handset. Here is the result of my efforts so far





not quite the Taranis but it'll do  :laugh:

regards
Andy

[Robotnik]

What a great project.
Here are a couple of links which might be of interest for the next stage, I bet you already know of them though.
http://www.reseau.org/arduinorc/index.php?n=Main.HomePage
http://flitetest.com/articles/custom-arduino-2-4ghz-rc-transmitter

I sail, drive, fly all sorts of RC stuff and some of it really only needs 2 channels.
Transmitters are a bind to lug around, I've often thought it would be nice to build a small 2.4g belt clip transmitter with a Wii Numchuck controller which I can just pop into my pocket when I'm not actually controlling anything, or even two Numchuck controllers for 4 channels, one for each pocket, maybe I'll get around to doing it one day.

Good luck with the rest of your project, I'm interested to see how it turns out.

[skyscraper]

What a great project.
Here are a couple of links which might be of interest for the next stage, I bet you already know of them though.
http://www.reseau.org/arduinorc/index.php?n=Main.HomePage
http://flitetest.com/articles/custom-arduino-2-4ghz-rc-transmitter

I sail, drive, fly all sorts of RC stuff and some of it really only needs 2 channels.
Transmitters are a bind to lug around, I've often thought it would be nice to build a small 2.4g belt clip transmitter with a Wii Numchuck controller which I can just pop into my pocket when I'm not actually controlling anything, or even two Numchuck controllers for 4 channels, one for each pocket, maybe I'll get around to doing it one day.

Good luck with the rest of your project, I'm interested to see how it turns out.

Thanks for the links. This is great. I hadnt seen either of those projects. It is nice to see what problems people had and solutions they come up with

I especially like the second one. I think an LCD module would be cool eventually, but to start with I shall probably just hard code my mixers in.

On that subject, I have had a couple of occasions where I have flown the wrong model. Now that I have an open source RC system, what would be nice would be to be able to give each RC model a unique identity, so when you switch on that model, the RC transmitter automatically selects the right mixes and settings for it. Will have to look into that and how it might work, but there seems to be the basics of it in the OpenLRS RF_MAGIC variable ( or some id value which is sent. My recollection of the source code may be a  bit hazy)

regards
Andy