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Jul 10, 2017, 09:01 AM
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Quote:
Originally Posted by athertop
You think the rfm module manufacturer would take note if you suggested they mod their design?
You would think they would. I suppose when I get a second I can just forward some links to a few posts. I am not holding my breath though!
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Jul 10, 2017, 01:22 PM
Registered User
dkemxr's Avatar
Pixracer is JST-GH

Quote:
Originally Posted by Marc Dornan
Clickmate are indeed what the Pixracer and Pixhawk are using.

As for the 3.3V supply to the RFM23BS, I think it is prudent to have it as an option for those that want to run the higher powers and have maximum reliability. It would likely be ok at 5V, but it clearly works more efficiently at 3.3v and stresses the biasing transistor less. I think Narpat nailed that pretty well, for me anyway.
Jul 10, 2017, 02:12 PM
Registered User
Quote:
Originally Posted by dkemxr
Pixracer is JST-GH
Apologies -- yes both Pixhawk Cube and Pixracer use JST-GH instead of DF 13 of Pixhawk 1. I expect the connectors will fit well enough on the DF 13 pads.
Jul 11, 2017, 01:55 AM
Registered User
Flipflap,

I know you have a feature planned for continuous transmit for testing purposes.
Is there a firmware file we can get from you to upload to the boards to test out our output power to see whether the board is damaged or not? Eg. with an swr meter/power meter

I've got modules here im not willing to use until i can confirm their power output and know they are working properly.

Thanks
Jul 11, 2017, 03:14 AM
Registered User
Thread OP
The problem is that continuous transmission (rather than say 50% transmit time) causes twice the heat so I don't recommend this approach.

Most digital power meters can detect the peak power and will give the correct value even in case of non continuous transmission.
Jul 11, 2017, 03:34 AM
Registered User
No worries, thanks for that. I'll have another play and see what i can work out with my swr meter
Jul 11, 2017, 04:51 AM
Registered User
Thread OP
This said, there's a another way to do power testing with ULRS :

RFM23BP can accept input signals up to +10 dBm without being damaged, but can measure RSSI in a linear way only up to -10dBm, so we've got to attenuate the signal to that level. (for signals between -10 dB and +10 dBm the RSSI reading will stay almost constant so it's unusable)

Configure an ULRS as TX and another one as RX as usual, and connect them together with a coax cable and sufficient attenuators to bring the signal to -10 dBm. As the output power can be approx 30 dBm, we've got to attenuate (at least) by 40 dB (30dBm - 40 dB = -10dBm)

Then read the RSSI value in ULRS CC, and add the value of your attenuator, for example 40 dB, and you've got the output power of your module.

The RSSI measurement of RFM23BP has a precision of 0.5dBm according to the datasheet, and we should estimate the coax loss and attenuator precision, but this should already give a good estimate of the output power.

You can also do the measurement with the spectrum analyzer feature of ULRS CC.

Be careful to select a coax with appropriate SMA connectors (male-male), or have a SMA female-male adapter and normal (male-female) cable.
Jul 12, 2017, 02:07 PM
Registered User
Did someone have freezes with rc control? It started after flashing on last firmware. Im using orange 1w modules. Telemetry works but speed is slower, 1.45K down and 25 up.
Last edited by chooi; Jul 12, 2017 at 02:35 PM.
Jul 12, 2017, 07:55 PM
Registered User
Maybe not the place to ask this but.....
Can you connect two devices to a blue tooth tx?
I would like to have a setup where I send Mavlink data to an OSD on the ground AND have Mavlink data on a laptop running mission planner.
Ideally I would like to run a 2.4mhz module on the RC tx, 2.4mhz receiver connected to a ground station, the ground station with blue tooth connected to a laptop. A distance away I would like the video receiver connected to a Bluetooth tied into an OSD.
I want the OSD on the ground so that if video is lost I can still have the Mavlink data up on the goggles....

I think the separation between VTX and ULRS ground stations is a good thing....
Jul 13, 2017, 11:19 AM
Registered User
I think only one device can be bound to a bluetooth at at time.
Jul 13, 2017, 04:36 PM
Registered User
Thread OP
Quote:
Originally Posted by Upnorth4
Maybe not the place to ask this but.....
Can you connect two devices to a blue tooth tx?
I would like to have a setup where I send Mavlink data to an OSD on the ground AND have Mavlink data on a laptop running mission planner.
Ideally I would like to run a 2.4mhz module on the RC tx, 2.4mhz receiver connected to a ground station, the ground station with blue tooth connected to a laptop. A distance away I would like the video receiver connected to a Bluetooth tied into an OSD.
I want the OSD on the ground so that if video is lost I can still have the Mavlink data up on the goggles....

I think the separation between VTX and ULRS ground stations is a good thing....
So if you want to have some separation between VRX and ULRS :

1) I'd suggest to use some length of coax cable as a simple first option. Let's say 1 meter in total should be more than sufficient.
2) Another option is to use a long USB cable. An USB cable can be up to 5 meters long, so if the ULRS and its antenna are in a location, it can be 5 meters away from the computer, and VRX.
3) A third option is to use the mavlink proxy. So basically you'll have the ground station computer running ULRS CC in mavlink proxy mode. Then you can connect any number of devices in wifi, and they will all be able to receive the mavlink data. For example you can have two tablets running Tower, three computers running Mission Planner, etc. It's really unlimited.
4) Then you can combine the options above, notice than an OSD will only require two wires to the ULRS module (serial data and GND), and this cable can be quite long (a user had success with a 20 meters cable). That's still another option to separate the VRX and the ULRS.

But to me the option 1) is the most obvious, just add 1 meter of coax to one of your antennas and it should be perfect.

edit : to answer your specific question about bluetooth, it's a one to one link, so we can't have 3 devices communicating by bluetooth. But the different options above should make you happy
Jul 13, 2017, 05:39 PM
Registered User
Could I "split" a line from the ULRS "TX" and have both a laptop via FTDI and the OSD connected at the same time?

I take there is no need for a "TX" on the OSD to be connected to the "RX" on the ULRS..... one wire only, the OSD would just listen to the same data as the PC/FTDI and send anything out....

Am I understanding this correctly?
Jul 13, 2017, 06:49 PM
RC fanatic
Quote:
Originally Posted by Upnorth4
Could I "split" a line from the ULRS "TX" and have both a laptop via FTDI and the OSD connected at the same time?

I take there is no need for a "TX" on the OSD to be connected to the "RX" on the ULRS..... one wire only, the OSD would just listen to the same data as the PC/FTDI and send anything out....

Am I understanding this correctly?
You are! You've got the concept spot on. Many of us do a similar thing with 2 devices - the BT module (tx/Rx both connected) which we connect our laptop to for Mission Planner, and in my case the 2nd device is a Teensy micro processor board which takes the Tx only from ULRS to get the mavlink stream and convert it to FrSky S.Port (connects into S.Port pin in module bay on Taranis. It would also be possible to have any other number of devices also connected just to listen to the Tx from ULRS such as the OSD.
Jul 14, 2017, 03:40 AM
Registered User
Did anyone have problem with rc like my?
Jul 14, 2017, 03:06 PM
Just call me Justin.
Alright boys, this is going to sound desperate but that's where I am at this moment....

Does anyone have an old apm board they wanna throw my way...?

I'm so sick of trying to get my naze going with inav/mavlink/gps so I can fly any one of my crafts..... I have spent most of the last week trying to get them to even send out a mavlink signal and even to pick up the gps... it f*&^/#^g lame. It sucks, cause I just started a new job(low pay) and I won't be able even buy a FC for prob about a year. All I wanna do is test out my ulrs setups and play with the new software you guys have been working so hard to fine tune.

Like isaid. Desperate..... plz don't flame me.....

Sincerely,
"Broke and wanna fly Justin"


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