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Aug 28, 2019, 10:20 AM
Carbo (-nator) ;-)
D8R-IIPlus and presumably a D8R or D8R V2?
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Aug 28, 2019, 10:35 AM
Registered User
D8R V2 has a meteoric version of D8, retired quickly after release, due to public disappointment. It is missing A1 input - permanently tied internally via an 1:4 divider, to measure receiver voltage.
Everything else is the same, including firmware.
The most important issue with this receiver is the serial line, it is not complete. The middle pin is not serial Tx, but +5V !
As a result it can't be programmed using the hub pins, but directly using a serial TTL adapter and some programming pads.
Aug 28, 2019, 11:42 AM
Carbo (-nator) ;-)
Quote:
Originally Posted by renatoa
As a result it can't be programmed using the hub pins, but directly using a serial TTL adapter and some programming pads.
The 8 pads between chrystal and antenna socket? Is a pinout available?
Aug 28, 2019, 02:20 PM
ErskyTx Developer
Mike Blandford's Avatar
Thread OP
The D8R-IIplus is the easiest of those 2 to re-flash. I've just added some more instruction to the first two posts.

Mike
Aug 28, 2019, 03:48 PM
Carbo (-nator) ;-)
Yes, but of course I would like to use D8R also. From what I have read, flashing should also work with a 3.3V FTDI connected to PA9, PA10 and GND. Is this the right track?
Aug 28, 2019, 03:51 PM
ErskyTx Developer
Mike Blandford's Avatar
Thread OP
Yes PA9, PA10 and GND are the correct connections.

Mike
Aug 28, 2019, 04:31 PM
ErskyTx Developer
Mike Blandford's Avatar
Thread OP
A first test version of the firmware is now on the first post.

Mike
Aug 29, 2019, 04:56 AM
Carbo (-nator) ;-)
First flash and bind attempt went flawlessly. Here is my working RS232 adapter cable (ignore the diode). RX and TX have to be crossed between RS232 and RX.

Looks very promising, thanks Mike!
Aug 29, 2019, 05:49 AM
ErskyTx Developer
Mike Blandford's Avatar
Thread OP
Great! Please let me know what Tx/module you are using and which mode (FCC/EU). I'm testing as many Txs as I can in both modes. I found late last night that my QX7 (EU-LBT), did not receive the telemetry very well, all other transmitters seem OK. I found this morning I need to delay sending the telemetry packet a bit for the QX7 to work OK. I now need to check the revised timing on other transmitters.

Mike
Aug 29, 2019, 12:29 PM
Carbo (-nator) ;-)
Here is the first rangetest with FCC/X9E/XJT. It managed about 100m in rangetestmode, From 1200m lost frames increased rapidly and telemetry loss/recover happened. But in a rhythmic way, hard to guess why. Test was stopped in 2600m distance. RX antennas mounted in a "V", X9E TX antenna horizontal, so not optimal.
Is there a chance to send lost frames in % and in a gliding average? It is clearer (and I'm used to it ).
Btw. we found a solution to test this legally.

Edit: I had a BT modem active on the quad, eventually it disturbed reception. I will disable it.
Last edited by Allerhopp; Aug 29, 2019 at 12:55 PM.
Aug 29, 2019, 05:20 PM
ErskyTx Developer
Mike Blandford's Avatar
Thread OP
Was the D8R-IIplus in control of the quad or was it a passenger?
If a passenger, what was the Rx that was in control and was it transmitting telemetry?

A script might be able to convert the raw lost frame data to what you would like to see.

Range also depends on the height of the aircraft, how high were you flying. Of course, we don't know how many lost frames you get with a X8R.

Mike
Aug 29, 2019, 06:22 PM
Registered User
I assume the "100m" in the post before was really meant to be 1000m.,....... ?
Then losing frames at 1200m,.

Or maybe 100m did mean in RangeTest Mode of the TX. (I thought you meant you meant you were doing a range test..... testing range...)
Aug 29, 2019, 11:59 PM
Carbo (-nator) ;-)
The quad was controlled with a R9mm 868MHz RX transmitting also telemetry. And I forgot to switch off a 2.4GHz bluetooth modem mounted on the quad. Recently I flew a 0.1mW rangetest with ACCESS LBT and a RX4R. Hard to compare, because lost frames (5100) are shown in %.

I will crosscheck with a small quad controlled by the D8R and no other RF device on board.

@PeterVRC The flight started with Taranis XJT in rangetestmode (0.1mw). We switched to 100mW, when the link seemed to be broken in about 100m distance.
Aug 30, 2019, 04:13 AM
ErskyTx Developer
Mike Blandford's Avatar
Thread OP
How did you get the lost frames data? Was it from the SBUS output?

Mike
Aug 30, 2019, 05:04 AM
Carbo (-nator) ;-)
Quote:
Originally Posted by Mike Blandford
How did you get the lost frames data? Was it from the SBUS output?

Yes, using Tadangos Arduino link quality indicator connected to SBus.


I have SBus connected to my FC, but i get only 1500us+/-256us when Taranis sends -100% to +100%.


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