- Posts: 63
FQ777-124 Pocket Drone
- petsmith
- Topic Author
- Offline
www.banggood.com/FQ777-124-Pocket-Drone-...er-RTF-p-977881.html
Please Log in or Create an account to join the conversation.
- BirdBarber
- Offline
- Hummingbird Assassin
- Posts: 134
I haven't seen anything on here about it being Deviation compatible but...
This review says the FQ777-124 has "CX-10" printed on the green circuit board.
He tried the Deviation CX-10 protocols, with no luck.
Maybe it wouldn't be that difficult for somebody to mod the CX-10 green protocol.
www.rcgroups.com/forums/showthread.php?t=2432513
I hope somebody gets a protocol working for it. I love flying my CX-10 with my Devo 8S, and this one looks like it could be twice as fun.
Please Log in or Create an account to join the conversation.
- Richard96816
- Offline
- Posts: 208
The included transmitter is pretty bad, as usual.
Please Log in or Create an account to join the conversation.
- btoschi
- Offline
- Posts: 151
which means this needs a new protocol, not an option to an existing one.
Uses NRF, 4 channel fixed hopping (4D, 43, 27, 07), bind Address E7 E7 E7 E7 67,
sends 8 byte packets every 0.002 s (gosh, that would be 500 Hz, have to recheck that one).
20 xx xx xx ID ID ID CS on bind
then switches TX ID to ' ID ID ID E7 67'
and data packets are
00 AA BB CC DD EE 00 CS
center values are 0x32 (50) for AA-CC, did not check any further yet.
Very simple protocol, I'll need to hook up my MM to Devo and give it a try ...
Please Log in or Create an account to join the conversation.
- petsmith
- Topic Author
- Offline
- Posts: 63
Please Log in or Create an account to join the conversation.
- BirdBarber
- Offline
- Hummingbird Assassin
- Posts: 134
Please Log in or Create an account to join the conversation.
- Richard96816
- Offline
- Posts: 208
Why don't the reviewers mention how crappy the transmitters are? If they did perhaps the manufacturers would start making better ones.
Please Log in or Create an account to join the conversation.
- btoschi
- Offline
- Posts: 151
I have create a simply protocol which replays the init from SPI trace (well, the known parts, see below),
but it does not work yet.
It seems that I have a completely different FC and RF chip on my FQ777 "Pocket drone" than what SeByDocky has in his pictures:
www.drone-maniac.com/fq777-124-pocket-drone/
My Transmitter has "SJ-SF121T2.4G V1.1" "20150327" printed on the backside of the PCB,
layout slightly differs, the RF daughter board is different. No way to look at RF chip w/o breaking it up.
Then I opened up my quad and peeled off the white stuff which holds the quartz down to the RF chip.
The marking reads:
"SV7241A"
"SOA5m" (not 100% sure about the 'm' here)
"S592"
This seems to be SSV7241 2.4 GHZ GFSK TRANSCEIVER from South Silicon Valley Microelectronics.
Note that the Quad's PCB is red (which can be seen from outside), contrary to the green board found in others.
As I have sniffed SPI on the transmitter side I can confirm that this chip
must be a nRF24 clone, but it uses yet unknown registers.
Only programming the known ones on nRF24 does not work out ...
Here's the init sequence with first (bind) packet.
2.95084 0 W_REGISTER(1F) 00
2.95097 1 W_REGISTER(1B) 10 E1 D3 3D
2.95130 2 W_REGISTER(19) 06 AA A2 DB
2.95162 3 W_REGISTER(1A) 27 61 01 F8
2.95195 4 W_REGISTER(1F) 01
2.95208 5 W_REGISTER(18) BF 94 00 DF
2.95240 6 W_REGISTER(19) 77 48 9A E8
2.95273 7 W_REGISTER(1B) 76 87 CA 01
2.95305 8 W_REGISTER(1F) 02
2.95319 9 W_REGISTER(1B) A0 00 18 A0
2.95351 10 W_REGISTER(1F) 04
2.95364 11 W_REGISTER(18) 01 00 F0 00
2.95397 12 W_REGISTER(1F) 05
2.95410 13 W_REGISTER(18) 84 03 2A 03
2.95442 14 W_REGISTER(19) 90 BF 00 00
2.95475 15 W_REGISTER(1A) A0 0F 00 00
2.95507 16 W_REGISTER(1F) 00
2.95520 17 W_REGISTER(CONFIG) 0C
2.95532 18 W_REGISTER(TX_ADDR) E7 E7 E7 E7 67
2.95570 19 W_REGISTER(RX_ADDR_P0) E7 E7 E7 E7 67
2.95609 20 W_REGISTER(EN_AA) 00
2.95621 21 W_REGISTER(EN_RXADDR) 00
2.95633 22 W_REGISTER(RF_CH) 4D
2.95645 23 W_REGISTER(FEATURE) 04
2.95657 24 W_REGISTER(DYNPD) 01
2.95669 25 W_REGISTER(RF_SETUP) 26
2.95681 26 R_REGISTER(FEATURE) 00
2.95693 27 R_REGISTER(DYNPD) 00
2.95705 28 R_REGISTER(FEATURE) 00
3.10600 29 W_REGISTER(CONFIG) 0E
3.25498 30 W_REGISTER(STATUS) 70
3.25510 31 FLUSH_TX
3.25522 32 W_REGISTER(RF_CH) 00
3.25534 33 W_TX_PAYLOAD 20 15 05 06 50 39 00 89
3.25589 34 W_REGISTER(RF_CH) 4D
3.25602 35 W_REGISTER(STATUS) 70
1F xx seems to switch register banks, a datasheet should help out here.
Anyone else who can see a glimpse of red on his quadcopter's PCB,
so further investigation is of some use ?
I have ordered mine from banggood in july 2015 (red canopy).
Edit:
Found that the Nuvoton M452 Quad Copter Dev board uses the SSV7241, source code available at nuvotons site.
Unknown registers mostly matches what their 'Initial_Reg_Array' (simplified) does.
No docs, so still I need the datasheet to understand if that can be nRF24 compatible, or not.
Please Log in or Create an account to join the conversation.
- BirdBarber
- Offline
- Hummingbird Assassin
- Posts: 134
btoschi wrote: ....Anyone else who can see a glimpse of red on his quadcopter's PCB,
so further investigation is of some use ?....
.
I ordered mine from Banggood in Sept 2015. It has a red pcb in the quad. It's also the red canopy version.
Please Log in or Create an account to join the conversation.
- pawelsky
- Offline
- Makers gonna make...
btoschi wrote: Anyone else who can see a glimpse of red on his quadcopter's PCB,
so further investigation is of some use ?
I have the red PCB one, and can do some sniffing if necessary with the logic analyzer.
BTW would this datasheet help?
www.51wendang.com/doc/17acf0aab9524ce68d2de3cc
Download doesn't work, but the document can be browsed online.
Please Log in or Create an account to join the conversation.
- btoschi
- Offline
- Posts: 151
pawelsky wrote: Wonder if there is any progress on the FQ777 protocol
...
I have the red PCB one, and can do some sniffing if necessary with the logic analyzer.
Init and bind sequence of another copter could be helpful, even though I still had no good idea how to make this work.
Currently thinking of using arduino and TX's RF chip for further testing, but mainly I'm missing a tool to sniff data on the air
to understand what's going wrong there ... ideas on how to do this w/o too much hassle are welcome
Please Log in or Create an account to join the conversation.
- pawelsky
- Offline
- Makers gonna make...
If the datasheet I've linked in my previous post won't help I can record the init/bind sequence, but would you mind sharing some picture of where the SPI lines are to connect the analyzer to?btoschi wrote: Init and bind sequence of another copter could be helpful, even though I still had no good idea how to make this work.
Please Log in or Create an account to join the conversation.
- victzh
- Offline
- Posts: 1386
No, this datasheet is not a real datasheet, but a brief description. It does not describe radio well enough. So either SDR is needed, or some other sniffer based on nRF24 can be used.
Please Log in or Create an account to join the conversation.
- pawelsky
- Offline
- Makers gonna make...
Hmmm, 34 pages of brief description? It looked pretty detailed, but I guess pictures are missing when you browse it online.victzh wrote: No, this datasheet is not a real datasheet, but a brief description. It does not describe radio well enough.
Anyway - if I can help somehow - let me know.
EDIT: I wanted to try this downconverter before, so I think I'm gonna give it a go. Ordered...
blog.cyberexplorer.me/2014/01/sniffing-a...ng-nrf24l01-and.html
Please Log in or Create an account to join the conversation.
- pawelsky
- Offline
- Makers gonna make...
Please Log in or Create an account to join the conversation.
- bikemike
- Offline
- Posts: 42
drive.google.com/open?id=0B4toKKKJwI9jWn...SGY4dEMtdkN1bXEwNWFj
Please Log in or Create an account to join the conversation.
- Multirotor Go
- Offline
- Posts: 55
The only problem is that it seems there is two boards and I am not sure if both are on the same protocol
Please Log in or Create an account to join the conversation.
- kahuna001
- Offline
- Posts: 34
Please Log in or Create an account to join the conversation.
- btoschi
- Offline
- Posts: 151
Need to dig into the dirty details on FM Transmission now ...
I have my own code on Devo 8S running protocol following SPI Traces (with some unknown registers) and the original Transmitter running,
sniffed both using SDR# (on linux with mono 4.2), tuned to NRF Channel 7 (MMDS LO Freq is 1998Mhz) and zoomed up to same details.
Original Transmitter:
Devo witt NRF:
One can easily spot that these signals are no way tuned to the very same frequency,
and they clearly do not look anywhere like the captures on the NRF24 sniffing page .
Someone with RF knowledge can help me out here ?
Both signals should be GFSK, but I cannot identify it at all ...
Just as a side note: the nrf24-btle-decoder cannot identify any meaningful frames (prints random garbage) - even with my Devo code.
Please Log in or Create an account to join the conversation.
- bikemike
- Offline
- Posts: 42
I also implemented the nrf24l01 "promiscuous" mode to try and sniff packets but when I use this code with the ssv7241 it doesn't seem to receive many and they all seem like garbage.
Please Log in or Create an account to join the conversation.
- Home
- Forum
- Development
- Protocol Development
- FQ777-124 Pocket Drone