junkman12

iTrader: (73)

I have a ko mars-r I am trying to rig up with the 2.4 module out of a flysky gt3. I have done the corona diy modules in a couple other radios, but this is my first ko, and flysky, and it is throwing me a bit of a curve ball. All the other radios I have done, the ppm signal shows voltage anytime the radio is on. I cannot get the mars to show voltage on the ppm pin unless the fm module is in it. I have, ppm, v+, and ground jumped to the flysky module. The module powers on, but does not get any signal unless I plug the fm module in as well. As soon as I plug the fm module in I get .49v on the ppm pin and all works. If I take a multimeter with one lead on v+, and the other on ppm, It works as well without the module in it. I was wondering if anyone has ran across something like this before. I was also wondering if someone who has a mars could check there radio with the power on and module out and see if theirs shows any voltage on the ppm pin. Basically just checking between the 1st and 2nd pin from the top on the module pins. Here is what I have, like I said with the fm module plugged in it is working fine, but I really have no where to put the flysky module without making it look all rigged up. Thanks for any help



what I am having to do to get the flysky module to get signal

snoopyrc

iTrader: (2)

I really cant help you, but this is interesting. Those radios arent that much either. So are you just buying the flysky GT3 and then ripping the 2.4 out of it? I would like to see how this goes.

junkman12

iTrader: (73)

consider it hacked! Thanks to a helpful member on rcgroups. I needed to add a 12k resistor between the ppm and v+ pins. to mimmick the fm module. Now just need to mount up the 2.4 antenna and tidy everything up. snoopy you are correct. Just used the 2.4 module out of the gt3, and wired it into the module pins of the mars. Now have a good quality ol radio with convenience of 2.4 and cheap rx's.

reptile

iTrader: (138)

Thought i would post this up here to help you guy's wire or know what the pins on the flysky module are for so you can do this mod very easy.

junkman12

iTrader: (73)

It is my understanding that the current gt3, and the gt3b, both have the same "version 3" 2.4 module. Just the gt3b's Is hardwired inside. I'll get some better pics today.

reptile

iTrader: (138)

Thanks
Also i have a old airtronics caliber 3ps i would love to make that 2.4 that's my favorit radio of all time... could it be done i never heard of anyone changing one to 2.4?

cdog4w

iTrader: (4)

It's module based, so definitely. You'll need to do some work to figure out what pins are what so you can plug the new stuff in correctly, but aside from that it should just work like it did for junkman.

junkman12

iTrader: (73)

and its done. Just came in from outside, glitch free and drove as far as I can see. I am just using this radio to get a bunch of old cars up and running again to play with around the house, I don't know how something like this would do in an actual racing situation, but for what its worth it works for me. I think the worst part of the whole deal was trying to solder the antenna wire back on the board. There is literally 1 strand of wire that runs to the antenna, and then the outer jacket. It was a major pia. The resistors I soldered in are under the shrinkwrap near the bind button. I mounted the module in there with some thick double sided tape, I had to trim some of the dead area around the board to get things to fit and the stock module cover to go back over it. I'll probably wish I had taken the time to mod it to run lipo, from what I read these boards do not like straight 11.1 lipo. But for now its done.

reptile

iTrader: (138)

Hi looks great!!
I have the regular mars not the R will it hook up the same?
Also have a Ex10 both have spektrum now but it sucks paying $50.00 or mor for RX's

Could you post a pic of a drawing showing how you wired it to what pins and stuff?
I can probably go by these but i am not sure if your wires shown are exact colors for plus and minus.

THANKS

reptile

iTrader: (138)

Also if you can't run 3s lipo on the flysky just put a diode reversed in line from the + power from the battery it will saftly drop the voltage you may need to put a few in line this way it will be like running fresh alkaline batteries.

snoopyrc

iTrader: (2)

Thank you for posting this. This is excellent.

reptile

iTrader: (138)

THANKS junkman12 for this great info!!
Here is my mars converted i can take out my 2.4 modual and use it in other radios like my ex10 also if i wish to.

skree

this of course will mean that you need to disconnect the battery when the radio is turned off, as your diodes in line will constantly draw power (albeit not very much) so requires a switch. It's easier, and better to put 8 LSD aa rechargeables in.. there is an alternative whereby the flysky circuitry can be made to like 3s lipo but it ain't cheap

I'd thought about rippng the module out of a gt2 or gt3b to upgrade an aged radio but couldn't find any way of having a bind button as i dont think its part of the module on those radios i think its part of the main pcb.

reptile

iTrader: (138)

Hi that's not true just put the diods in line out of the radios on off switch so when you turn it on diods are working and when you turn the switch off all power gets disconnected from the power source all together like how it normally does. You can also use a 9.9V Life pack and do nothing at all and it will be lighter and last longer than the AA batteries .

skree

yeah, that would work on radios with a proper on off switch wired rather than hard soldered to the pcb. you have to have some way of isolating the diodes from the battery when the radio is off.

LiFe won't last longer than decent LSD AAs, unless you have more mah of liFe than you do of AA, and to do that would require the rather bulky and damn heavy A123 26650 cells - a 3s pack of those (2300mah) would weigh more than half a lb.