Devo 8s upgrade with 3 new TX modules

At last I got around to also upgrade my one Devo8s with the additional TX modules. I also installed two additional external 2.4GHz antennas for the two modules most frequently used, the 3rd has an internal antenna.

This is probably how close we will get to the proposed single carrier board using 3 off the shelf modules without making a dedicated board. Since the Devo has two I/O lines to support two modules (TMS,TCK) I added a small toggle switch in the battery compartment to select to which module TCK is connected.

This way I don’t need any reconfiguration of tx.ini file when flying with the 3rd module.

My Devo 8s Triple now supports:

Standard Devo CYRF module:

• Walkera Devo 6/7/8/10/12; WK2401/WK2601/WK2801
• Nine Eagles J6 Pro
• DSM2/DSMX

A7105+PA Module

• Flysky protocol and WLToys V911, V9x9, and Xeida 9938
• Hubsan X4 protocol

CC2500+pa module

• Skyartec
• Frsky (in Future)

nRF24L01+pa Module

• V202 Protocol
• Future: Hopefully some Nine Eagles Planes

This is the end result:



The internal placement of the carrier board in the back shell with the three modules. Notice the 7 connector pins below the top module, this is for a connector with wiring to the main PCB which allows the front and back section of the transmitter to be separated by unplugging the wiring, keeping with Walkera's method to separate the two halves.



The Devo8 Main PCB connections. You'll notice the connections to the Devo TX module pins are here made on the module connector on the main PCB, the module has been removed in the composite photo:




And the battery compartment switch to select between CC2500 and nRF2401 modules:

FDR wrote: CC2500 and 24L01 are only two additional RF modules. What is the third?

Typo, now updated.

Nice, very clean setup. Could you tell me how long you can use the radio on a full charge? Do you see one module using more power than expected?

I have the Devo 7e with the A7105+PA module and am considering adding the nRF24L01+PA module, but am concerned that the battery life will be reduced even more. I get around 2 hours currently with four 2000mah AA.

Let me know your exact setup, which protocol you selected, power level during the 2 hours, level of the end voltage alarm, etc. Then I can fo apples with apples

I don't have exact figures since I haven't timed it. But I find that even when I'm using the built in module, with the DSMX protocol at 150mw, I still get around 2 hours. I fly until the batteries are drained completely, since I'm mostly indoors.

farad wrote: I don't have exact figures since I haven't timed it. But I find that even when I'm using the built in module, with the DSMX protocol at 150mw, I still get around 2 hours. I fly until the batteries are drained completely, since I'm mostly indoors.

For indoor flying you could probably get away with 10mW or maximum 30mW. Any higher is unnecessary unless you are in a high noise 2.4GHz area. Dropping down from 150mW and a having a fast screen dimming time-out on the display should get you at least an extra 30 minutes or more.

I use a Devo 8S with C2500 and A7105 Module. But, i have many Problems. With A7105 i cant bind Hubsan X4. And when i Mount the Antenna to C2500 Module, the Screen goes fully white Color. Any ideas? Do you have a schematic from your Mod? Which Firmware Revision do. you use? Tanks for helping

Nusbr you might have a short in your soldering check all connections if you sceen is going white or blank on you. Randmetal use a toggle switch to add the third module since the Tx only really have two connections. The two IO are (TMS,TCK) so take look at his picture. On the bottom of the TX lies those connection with VCC and Ground on top there is (sck,MISO,MOSI). If need further info check the "How to Guide" section of this forum about installing modules in your tx. Hope that helps

Hi there,

First of all, tks to all of you for the great job done with deviation... it rocks

I made the mod proposed here by RandMental, but I have some problems...
My hardware config is almost the same: Cyrf, A1705 (TMS) and a switch to choose from nrf24l01 and cc2500 (both connected to TCK). The difference: My switch is used to supply power to nrf24l01 or CC2500.

Everything seems to work exept when choosing v202, SLT or YD717... If I select one of these protocols and if I move the sticks (nothing happens without stick movments) after a while (from a few seconds to 1 minute) the transmitter resets connection and start a new binding procedure (note that i was not able to reproduce this with Hisky selected Hisky protocols does not seems to be affected )

Do you guys have any idea or suggestion to get ride of this mess!
Should i add a condensator somewhere?

I already double checkek my connections and my solders... looks ok
I tried to use the switch with TCK... same problem!

That means your nRF24L01 does not actually answer. The code for these protocols still contains busy waiting loop for RF chip to be ready to transmit (mea culpa!) and the disconnected chip can not be distinguished from busy. So eventually watchdog fires and Devo is restarted.

Check your physical connectivity to nRF24L01 module.

... Ok thanks victzh, i will then triple check it and heat every solder.
But why Hisky protocol is not producing a restart... Still a mystery for me

... well... no changes

tks anyway