Devo7e work

vlad_vy wrote: Most used dbi = about 2-5 dbi, no more.

OK, so I'd guestimate from it's size that the existing antenna is no more than 2dbi, would a 5dbi antenna give an appreciable range increase without a module hack required?

[EDIT] Does this pic represent what you mean for higher gains? ie., the pattern gets progressively narrower as the gain gets higher? SO you'd have to be more careful to always aim the antenna perpendicular to the model? ie. angled or 90degree antenna, and always moving your TX...

2dbi -> 5 dbi = 3dbi = 2 times of power = 1.4 times of range

Yes, this image is a good representation of antenna dbi and antenna directivity.

That picture represents the gain at a single frequency (the resonante frequency of the antenna). As you move away from this frequency, up or down, the pattern stay the same, except the absolute gain reduces (the horizontal axis shrinks from both sides to the center.

Antennae design is a tradeoff between gain, directionality and bandwidth (and matching impedance). I seriously question any stub antenna, as those sold on eBay, with reported gains of more than 3dBi (x2). It is just physical and theoretically impossible to get these high gains from a passive ¼ wave, ⅝ or dipole antenna in that form-factor.

The Devo 7e antenna has a gain of 2.81 at 2405MHz and it drops to 1.12 at top of the band 2479MHz

PhracturedBlue wrote: Th V911 module will not be affected by this limitation on the CYRF module. I'll try to get you pin-outs tonight.

Would be appreciated, iv already prepared the v911 module with wires, just need to know where they go on the 7E.

Ps you might want to update the pdf with this tip.

Unsoldering the flysky module is very easy if you just connect all the pins with solder, then you can just pull it straight out when you heat the solder.

Then you still have all the pins, and their great for supporting you when you solder the wires to the module.

PhracturedBlue wrote: Here is the pin out:
From left to right:
1) Chip Select
2) CLK
3) MISO
4) MOSI
5) Reset
6) Vdd
7) GND

note that like the other Tx, you probably don't wanttouse the Vdd connected to the module, as it is likely battery voltage, an the V911 module requires 3.3V. You can get that from the 5pin header right below the module.

Thanks, I'm presuming you disassemble the 7E similar to how one would disassemble the 10? Haven't gotten around to opening up mine yet.

Xermalk wrote: 7 ? ouch, i wonder how that would work with my master cp.
Mind making a Guesstimate on how long the range would be on a Master CP with 7 mW?


Anyway, im guessing this is what we would need to upgrade the range?

www.ehirobo.com/shop/product_info.php?products_id=11530

Edit: Hrm, only 7 solder points on the 7E Module? the 8s one seems to have 10

A quick range comparison using a Walkera V200DO2:
Devo 7E with Deviation @150 mW ~80 m
WK-2801 Pro (10 mW?) ~120 m

PhracturedBlue wrote: Here is the pin out:
From left to right:
1) Chip Select
2) CLK
3) MISO
4) MOSI
5) Reset
6) Vdd
7) GND

I Checked out the flysky pdf but its using different names for the pins.

So i'm unsure where the Flysky pins go

1) SCS -> Chip Select?
2) SCK -> CLK?
3) SDIO -> MISO?
5) GND ->7 GND
6) 3.3V -> 5 pin furthest right hole - Vcc

PhracturedBlue wrote: Almost.
SDIO<->MOSI
You don't connect to the chip-select pin with the Flysky module. you use the 'TMS' pin (unlabeled but it is the 2nd pin on the pin header below the module as in the Devo8/10)

Just to be fully sure i got everything right.




Edit: Corrected pins.

PhracturedBlue wrote: (1) is wrong. it goes to the 2nd pin of the 5-pin header (just like on the Devo8/10)

Image corrected, feel free to reuse it if you make a 7E/Flysky guide/pdf.

PhracturedBlue wrote: Double-checking my notes, I have MOSI and MISO swapped in the list above. If so (3) connects to the 3rd pin from the right. I don't have my Tx in front of me, but it looks like the pinout of the module is actually:
CS
CLK
MOSI
MISO
RST
VCC
GND

Good thing i checked the thread before soldering heh, moving pin 3 1 step to the left on the rx then should fix it.

soldering 2&3 next to each other might be a bit tricky though. Ill likely solder one onto the rx and the other on the 7E pcb.

Done soldering, but i cant seem to get it to bind to my v939.
Binding still works with devo, so at least nothing is shorted.
Is there any way to check that everything is ok without binding it to something?.


This is how i soldered it

Ok, ill just semi fixate it inside until its been tested, or you release a test build.

Im using the same nick, Xermalk on skype in case you want realtime testing done.