OpenLRS - thUndead's MODs :D

[thundead]

Nigel check first post ;)

Here's my method of making a 1/4 wave 459MHz antenna...

http://www.fpvuk.org/forum/index.php?topic=2925.msg28229#msg28229

Nigel.

[ghost2212]

Great work thundead, Am currently in the process of designing a board to use the openLRS firmware and then maybe hoping to have an all inone board that integrates my multiwii controller with the open LRS, Do you think it would be possible to produce a 459mhz booster if it is needed much like the 433mhz one that flytron sells?

Thanks

Brett

[thundead]

Hey Brett,

If you look @ the flytron booster's datasheet, the IC's freq range is:  400-470MHz so can be used without any problems with our 459Mhz band.

Only problem is that you only get Unidirectional link meaning no telemetry (which is fine with me haha).

Also power output is proportional to input voltage. apparently goes from 0.8W (3.7v) up to 10W(9v)

So my take on the booster is this:

use this schematic: http://www.flytron.com/pdf/7w_booster_schematic.pdf
Implement an adjustable switching voltage regulator (buck ) for your Vin and there you go :D

I'd suggest this one: LM2576HVT-ADJ (not the high voltage version though) << I used this in  an ROV project to step down 48v to 12v for my cameras.

Might be other ICs out there but something in those lines :)

Can give you a hand with circuit design and PCBs.

Regards,
Mihai.

[SouthPawPaul]

Are these FWs based on the latest from Flytron and are they compatible with both the v1 and v2 Rx/Tx boards?

I've just modded my 5v FTDI board to 3.3v so I'm about to upload and didn't want to brick my boards (if that's even possible with an Arduino!). I have the v2 boards.

[SouthPawPaul]

Additionally, can I check the RSSI without additional equipment. I'm guessing not.

What's the best way to go about monitoring it?

[thundead]

yup, FW compatible with both v1 and v2 boards.  Just change you board in the config.h file :)

I used a multimeter :D

[thundead]

for v2 boards,

if you want rssi change

    #define RSSI_MODE 0 //0=disable  1=enable
      #define RSSI_OUT 10 //Servo7 or RSSI

to    #define RSSI_MODE 1 //0=disable  1=enable
      #define RSSI_OUT 10 //Servo7 or RSSI

in the config.h, #if (RX_BOARD_TYPE==2) section !!!!!!!!!!!!

otherwise RSSI wont work.

I personally have v1 hardware.

[pk-surfing]

thundead,

It looks like the Red Bull and Pringles are the trigger for your inspiration....

(from your first post)
"After some Redbull and Pringles I finally came up with an experimental implementation for FHSS."

I'm sending you a PM asking for your PayPal address so I can at least get you one round of Pringles and Red Bull in.... you're putting in a lot of time with this programming that we are all benefiting from so it's my way of helping a bit (cos I can't hack the programming !)
:cheers:

PK

[thundead]

Many Thanks PK. Much appreciated! you should see a tinyurl link in my signature :)

thundead,

It looks like the Red Bull and Pringles are the trigger for your inspiration....

(from your first post)
"After some Redbull and Pringles I finally came up with an experimental implementation for FHSS."

I'm sending you a PM asking for your PayPal address so I can at least get you one round of Pringles and Red Bull in.... you're putting in a lot of time with this programming that we are all benefiting from so it's my way of helping a bit (cos I can't hack the programming !)
:cheers:

PK

[SouthPawPaul]

OK. I've had a play.

I uploaded "Devonian's Original UK FW + thUndeadMOD" to both my v2 Tx and Rx and changed the board types to v2 in the code and also enabled RSSI in the Rx code.

Both of my Tx and Rx units are using 459Mhz custom whip antennas.

Here are my observations.

Failsafe
Can't see a problem with my simulated test. This is powering the rx with a standalone lipo on a BEC and a single servo on channel one. Switching off the Tx does indea set the servo into it's failsafe position.

I do however have an observation, but it's not specific to your firmware, but is also apparent in the standard UK firmware from the Google code repository. Occasionally when I turn the Tx back on again after simulating a failsafe condition, the Rx lights flicker rapidly (Red and Blue alternating) and the servo movements are very jerky but still responsive. This can sometimes clear in a second or two, but sometimes can persist for longer. Do you have any idea what could be going on here?

RSSI

I measured the RSSI voltage on servo pin 9 and when the Rx and Tx are sat next to each other I get a reading in the region of 1.7v. When I move to the other side of the house the RSSI voltage goes up to 1.75v. Now I expected the RSSI voltage to drop as I assumed the closer to 0v the worse the signal was getting.

I'm also assuming that when the red led rx light flashes that that is indicating a packet loss. Do you have any ideas?

I know these are really questions for Melih, but I thought I write up my results here of your custom firmware and keep all my observations and question in one place.

Paul

[SouthPawPaul]

I guess also that testing FHSS is going to be just ensuring the Radio link is consistent. Without a frequency analyzer there's not a great deal else to test?

[thundead]

...Something big is coming for the openLRS (sometime tonight).... be sure to watch the first post :D

[thundead]

Thanks for the feedback. Ive got the v1 hardware so can't test the v2 boards but from what I see from the code, the pin for rssi is 7 I think. I'll have a look begore releasing tonight's fw :)

Cheers,
Mihai.

OK. I've had a play.

I uploaded "Devonian's Original UK FW + thUndeadMOD" to both my v2 Tx and Rx and changed the board types to v2 in the code and also enabled RSSI in the Rx code.

Both of my Tx and Rx units are using 459Mhz custom whip antennas.

Here are my observations.

Failsafe
Can't see a problem with my simulated test. This is powering the rx with a standalone lipo on a BEC and a single servo on channel one. Switching off the Tx does indea set the servo into it's failsafe position.

I do however have an observation, but it's not specific to your firmware, but is also apparent in the standard UK firmware from the Google code repository. Occasionally when I turn the Tx back on again after simulating a failsafe condition, the Rx lights flicker rapidly (Red and Blue alternating) and the servo movements are very jerky but still responsive. This can sometimes clear in a second or two, but sometimes can persist for longer. Do you have any idea what could be going on here?

RSSI

I measured the RSSI voltage on servo pin 9 and when the Rx and Tx are sat next to each other I get a reading in the region of 1.7v. When I move to the other side of the house the RSSI voltage goes up to 1.75v. Now I expected the RSSI voltage to drop as I assumed the closer to 0v the worse the signal was getting.

I'm also assuming that when the red led rx light flashes that that is indicating a packet loss. Do you have any ideas?

I know these are really questions for Melih, but I thought I write up my results here of your custom firmware and keep all my observations and question in one place.

Paul

[thundead]

Hehe :P all I can say now is tx on micro mode in the opposite side of my house + rx in washing machine (Faraday cage attempt haha) = perf sig :D

Still need to brush up some code and I'll also try to use the 458Mhz spectrum. After that FW ready for use :D
Here is me right now haha


Mihai.

...Something big is coming for the openLRS (sometime tonight).... be sure to watch the first post :D

Nobody likes a tease  :P

[SouthPawPaul]

I've just checked the firmware and in Config.h there's the following line

Code Select Expand


#define RSSI_OUT 6 //Servo9 or RSSI


I'll check again tonight just in case there was some "finger trouble" ;)