DIY "FlySky" RF (Transmitter) module

[copterrichie]

Here we go!! About Freaking time.

http://www.rcgroups.com/forums/showthread.php?t=1921870

[NikTheGreek]

He he....

[Sebbi]

What would one do with a DIY TX? The reported range in that thread is just 100m

[copterrichie]

What would one do with a DIY TX? The reported range in that thread is just 100m

I see you did not read much as usual, there are amplifier and antennas to increase the range. The Fact that it can be done as a DIY project opens the doors to endless prospects.

[Sebbi]

You can amplify everything (including the original FrSky TX), but what is the benefit of having a DIY TX? Why emulate the FrSky protocol and not run your own? What are those endless prospects?

[copterrichie]

You can amplify everything (including the original FrSky TX), but what is the benefit of having a DIY TX? Why emulate the FrSky protocol and not run your own? What are those endless prospects?

May be some folks love to build stuff verse being marketed and SOLD stuff? Is that a possibility? Other folks may like setting new trails and not be a follower, is that also a possible? So folks like to think for themselves verse having things forced on them, yet is that another possibility? Just because you LIKE buying your way though this hobby, other people may just enjoy DIY.

If Possible, I would like to see a picture of your copter(s) please? Just curious.

[Sebbi]

Why so hostile? You are not forced to buy FrSky transmitters/receivers ... so why DIY them and not run your own protocols? Doing it by yourself is fine by itself but you mentioned "endless prospects" ... what prospects?

[copterrichie]

Why so hostile? You are not forced to buy FrSky transmitters/receivers ... so why DIY them and not run your own protocols? Doing it by yourself is fine by itself but you mentioned "endless prospects" ... what prospects?

LOL LOL

Negativity are WE! What about other protocols like Hubsan or a Custom design especially for the WiiCopter? You are aware there is work already in process to integrate the Flight Control with the RX right?

[Sebbi]

And why do you need an emulation of the FrSky protocol for this to happen? What is the benefit of that other than being able to use a stock FrSky RX with your DIY TX?

[copterrichie]

And why do you need an emulation of the FrSky protocol for this to happen? What is the benefit of that other than being able to use a stock FrSky RX with your DIY TX?

Ok, I will play along for the fun of it, what is your interest in this line of questioning? You made your point of it not being a worthwhile venture for you? Could it be that you don't want others to give it a try?

[copterrichie]

A match made in Heaven: (build a diy flysky/turnigy rx from SCRATCH!) http://www.rcgroups.com/forums/showthread.php?t=1798913

[Sebbi]

And why do you need an emulation of the FrSky protocol for this to happen? What is the benefit of that other than being able to use a stock FrSky RX with your DIY TX?

Ok, I will play along for the fun of it, what is your interest in this line of questioning? You made your point of it not being a worthwhile venture for you? Could it be that you don't want others to give it a try?

I realize my postings might look like trolling, but I am really interested in the kind of applications a DIY FrSky TX (or RX) would be better than the stock modules. You posted a link to the original reverse engineering article which displays a super small DIY receiver. That's a nice application right there! What I don't understand is, why it has to be the FrSky protocol or why it is special that a DIY solution uses that protocol. Why not implement your own stuff if you go the DIY route? What is the killer argument for using something like this on the TX side?

[copterrichie]

And why do you need an emulation of the FrSky protocol for this to happen? What is the benefit of that other than being able to use a stock FrSky RX with your DIY TX?

Ok, I will play along for the fun of it, what is your interest in this line of questioning? You made your point of it not being a worthwhile venture for you? Could it be that you don't want others to give it a try?

I realize my postings might look like trolling, but I am really interested in the kind of applications a DIY FrSky TX (or RX) would be better than the stock modules. You posted a link to the original reverse engineering article which displays a super small DIY receiver. That's a nice application right there! What I don't understand is, why it has to be the FrSky protocol or why it is special that a DIY solution uses that protocol. Why not implement your own stuff if you go the DIY route? What is the killer argument for using something like this on the TX side?

Bingo and that is the very point I was MAKING, it does not have to be. This DIY is only a foundation or stepping stone to much greater.

[copterrichie]

FYI, I have toyed with the RSERIAL but found it to be slow. I know others have had better success and this is why I am looking at developing this technology. There is no reason in my mind as to why this transmission system could not be in binary with unlimited or greater capacity. In other works, more than 8 or 12 channels etc.

[crashlander]

@Copterrichie
To add some marketing to RCSERIAL (now enabled by default)
The following video (apart from being boringly long) was taken using DIY TX using only APC802 on TX and APC220 on RX side running (one way link) with 19200 baud and completely over 200mW 5.8G FPV link and I believe that latency of TX-RX is unobservable http://www.youtube.com/watch?v=eX_ccO0m3Uk
And measured range on the ground in the city is aprox. 800m (that is not flying, but between buildings)(somebody will add that you can get shot in Europe for using this technology that way).

Regards
Andrej

[copterrichie]

@Andrej, first, that video is not BORING!! Perfect for showing the surveillance capacity these aircrafts. Personally, I am not interested in flips and fast maneuvers but getting to a fairly good altitude and collecting data for studying. So the datalink has to be fast enough for not only sending control commands but telemetry data and other on-board sensory data.

P.S. When I stated others have had good success, you were one of the people I was thinking of. Great Job!

[city_kid]

@Andrej
@copterrichie

I've been testing out various homemade TX / RX / Telemetry transceivers.

I wanted the following specs:

1) Long (line-of-sight) range - I don't feel confident enough (mainly in my own abilities) to fly a copter outside of observation range.
2) High speed, with zero latency - I want to use MSP messages TO the copter for RC control, plus constant telemetry back from the copter to use on a "ground station" application.
3) Low cost....?!
4) Electronically simple - TTL serial in and out
5) If available, RSSI.

So far I've tried the following:

Bluetooth: Very simple to implement but very limited range.

nRF24L01+LNS_PA: Long range 200mW 2.4GHz, BUT only has an SPI interface so I had to build / code an ATmega based TTL Serial to SPI convertor. Problems: Conversion introduces latency and limited packet / message lengths. Worked pretty well.

HopeRF HM-TRP: These are the modules that are used in 3DR Radio Telemetry products. 915MHz (or 433MHz) at 100mW output. Range OK, but BIG problems with latency. The radio traffic is abstracted by the MCU and there can be like a ONE second delay... Pretty unusable...!

WiFi Serial Link: These are easy to setup, but the range is a little limited. 2.4GHz amplifiers are a possibility.

Shuncom SZ05-TTL-ADV: These are awesome! They are 2.4GHz 250mW bi-directional TTL serial transceivers. Only US$43 for a pair! Work up to 115200 baud. Zero (very very small) latency. Small size. Could be used with an RF Amplifier or WiFi amp from Ebay. One slight downside is no RSSI function, but considering the range tests I've done, I don't think it will be a problem. If I can't see my copter then it's out of range anyway! The SZ05-TTL-ADV model number breaks down like this: "SZ05" is the basic module (it's actually) ZigBee, "TTL" means 5v TTL serial (they do a +/-12v RS232 and RS422 version), and "ADV" is the high RF output (250mW instead of 50mW).

To test my range I did the following:

1) Setup my MultiWii, I2C GPS Nav board and SZ05 transceiver with a battery and BEC.
2) Used my modded "constant telemetry" code to get the MultiWii to bang out telemetry (GPS) data.
3) Used a laptop inside my apartment running MultiWii WinGUI to record a GPS path.
4) Walked around my very urban, inner city neighborhood...

Here are the results:

SZ05 Range Test

As you can see there is no break in the GPS track, meaning that the GPS data was getting back to the base station laptop OK. Distance is probably 250 - 300 metres (beyond observation range) and going through 4 or 5 big steel and concrete apartment blocks! The manufacturer claims 2000 metres line-of-sight, and talking to some RF Gurus here at work, they agree, these modules would go a long way!

These SZ05-TTL-ADV modules are available from Ebay from the manufacturer on Item Number 221257716266.

The modules can be set up as point-to-point, star or mesh networks, and you can even put a remote "relay" module to extend your range.

Back to the original subject of this thread: FRSky. I have looked into these but found some issue, not least the baud rate.

Hope this help you guys or anyone looking for full digital serial control....

city_kid

[gompf-2]

The Shuncom modules look very promising.

Back to the original subject of this thread: FRSky.

? FlySky !=FRSky
The DIY FlySky stuff "works" but was never ment as a duplex link.

[city_kid]

@gompf-2

Sorry, but I thought that was a typo! My mistake.

I've not seen this "FlySky" project, but the hardware is similar to one of my solutions.

The RF transceiver modules that they're using are SPI interfaced like the nRF24L01+ modules that I am still using on my development platform. You need an ATmega / Arduino chip to interface the SPI RF Module to the outside world. In the case of FlySky they are encoding / decoding PPM pulse streams. I my case, I am encoding / decoding serial data for control and telemetry.

The modules that FlySky is built to work with don't appear to be very high RF output. Only max 1dBm I think, so not great range...

Best of luck anyway, and I'll keep an eye on your progress...

Cheers!

city_kid

[gompf-2]

Hi,

Best of luck anyway, and I'll keep an eye on your progress...

It´s not my project, I just addes some lines for failsafe/cheapduino.