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The OpenLRS Project: PCBs ready for test

Posted by Melih Karakelle on December 24, 2010 at 11:00pm

Hi Guys,

I received the OpenLRS PCBs and we start to working about firmwares.

This is the Tx module of OpenLRS, It gives 100mw 433mhz RF power and its penetrating behind 5-6 concrete building!, we will test it on flight for range. System can controllable by any PPM signal or over RS232(bidirectional)

This is the Rx of OpenLRS,

It is very small receiver that supporting I2C (for IMUNext) and RS232 Telemetry. It sends the RSSI level over telemetry and RSSI output (PWM).

And our killer 7W Booster for very long range oneway RC control.

All Atmega328 processors including MegaLoad bootloader for firmware update over rs232. All AVR programmers are welcome.

They will in stocks before 2011.

You can follow the OpenLRS project from here

Cheers and Mary Christmas

Melih

lrs, open, openlrs

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Comments

Cronselaar January 21, 2011 at 12:00pm

Me too...
Jhon December 30, 2010 at 8:47am

does it have any button fr range check?
Melih Karakelle December 29, 2010 at 10:17pm

Yes, Yesterday we visited the RF lab of a television station. They have million $ equipments and much more experience about RF and tested our equipments. Power/noise ratios was perfect, Output powers was 100% same as our design powers. Only problem was my logic, OpenLRS devices was configured on usage mode and it's mean transmitter working only %50 of time, but RF power meters measuring total energy and all values was half :(
I will configure it for full time tx mode and visit the lab again to capturing the output screens of power meters.

LRS(one way radio) firmware ready for first tests, i'm working on bidirectional telemetry firmware now.

- Antennas ordered,
- Futaba and Jr cases ordered(for one way RC users)
- 7w booster chips arrived(20 units)
- Gyro and Accelerometer chips arrived (for direct imu)
details coming...
Jhon December 29, 2010 at 7:53pm

looks like OpenLRS passed the laboratory test:

http://twitter.com/flytron/status/20188860147302400
Earl December 27, 2010 at 8:45pm

Having it in a futaba form factor with my er9x and telemetry from my autopilot would be nice.

right now I use xbee inside the er9x and display data on er9x lcd screen.

\Earl
Jhon December 27, 2010 at 8:17pm

maybe you could add a buzzer to the receiver too, so in case its lost, there is a "beep beep"
Melih Karakelle December 27, 2010 at 3:48am

Hi Johann, yes, i'm planning to doing that. Because the transmitter sending the servo positions over digital RF module and we can read this values from PC(rs232) or any PPM source. Search my blog posts, i remember some comments about that on another post.
Melih Karakelle December 27, 2010 at 3:24am

@Jhon, RF module already including 20+ component for filtering, i guess they are enough for most of case.

@Kamu, You cant compare it with other FPV LRS systems because other ones using one way transmission without telemetry and Trappy using 2W (on booster mode) transmitter. mean, you have 2W parasite source on the plane when using telemetry. I'm designing it for opensource receiver usages as onboard stabilization, telemetry, etc. For only "long range", you can choose the solution from other brands or use my booster.
Jhon December 26, 2010 at 8:37pm

eap, thnks @Renato

@ Kamu Johansen any way, you can user high gain antenas,
500mw = 27dBm
100mw = 20dBM

use a 7dBm antena with the OpenLRS and its like if you had 500mw output ^^
Renato Aranghelovici December 26, 2010 at 12:02pm

I wonder how a higher frequence transmitter could jam a lower one...

Probably you have read about harmonics, but these are exacty the oposite ;) the 3rd harmonic of 433Mhz could influence 1280MHz video , and not the reverse.

It's like saying that 5.8Ghz video could infuence 2.4Ghz RC ;)