Extra 3 position switch

[wojtek76]

Does anybody know how to replaced 2 position switch with 3 position switch?
I need for my configuration 2 x 3 position switches.
Thanks.

[pmackenzie]

You will either have to combine two 2 position switches into on 3 position one, or possibly replace a pot with a 3 position switch
The use the custom switches to produce the 3 settings you need.

You could also leave the two 2 position switches in place and use the custom switches to combine them into a 4 position switch.

Pat MacKenzie

[man-bis]

Does anybody know how to replaced 2 position switch with 3 position switch?
I need for my configuration 2 x 3 position switches.
Thanks.

Such a mod can be done as shown here:

[pmackenzie]

That is probably the best way to do it.

You could also leave the pot in and add a SPDT switch to select either the centre tap of the pot or the centre terminal of the switch as the input to the mcu.
One way the pot would still work, the other way the 3 position switch would work.

Pat MacKenzie

[jhsa]

there's only one problem.. you would have the resistors in parallel with the pot

[pmackenzie]

All the pots in the transmitter are in parallel between Vcc and ground, you are simply adding one more set of fixed resistors
The added switch will choose between the pot and the switched voltage divider

Pat MacKenzie

[jhsa]

true.. didn't think about that..

[wojtek76]

Does anybody know how to replaced 2 position switch with 3 position switch?
I need for my configuration 2 x 3 position switches.
Thanks.

Such a mod can be done as shown here:

Thank for help.
I replaced pot3 as you show me on picture, but something is not Wright. Switch only switch to high,low,low. Any clue what could be wrong?

[jhsa]

You could try something like this.. Just an idea.. Don't know if it makes any difference..
On the other picture the switch was shorting one of the resistors leaving only 2.5k between 5V and GND.. This way it replicates the values of the pot at the middle and end points.. Sorry about my English

João

[MikeB]

Looks good to me.

Mike.

[flyboy]

Can we replace a 2 position switch to 3 position with this mod?

[Kilrah]

No.

[HC1969]

New idea:


Multi-function switch.
Each steps can be on a different function.

[Kilrah]

Yep that's a common use for the guys who use Ardupilot. A 5-position rotary switch with a resistor ladder on an analog input

[Outbreak]

You could try something like this.. Just an idea.. Don't know if it makes any difference..
On the other picture the switch was shorting one of the resistors leaving only 2.5k between 5V and GND.. This way it replicates the values of the pot at the middle and end points..

João

Hi i have a question.. in my city i couldent find 2.5k ohm resistors.. but i found 2.2k ohm. if i try to do it with 2.2k ohm resistors, will it work ?

[jhsa]

I guess it will work but to be safe I would go for 2.7K. Maybe you can find them better as they are more a standard value than 2.5K

João

[Outbreak]

what can be the danger of using lower k and higher k ?

[jhsa]

Higher K, no danger at all.. lower K, if it is to low will draw more current from the voltage regulator.. in this case I think it is not a big difference, but don't forget that all the pots are in parallel, and if you lower one of the values to much it could make a big difference.
Normally we have seven 5K pots in parallel on the 9x being fed with 5V.
that means a parallel resistence of 714 ohm. the current draw of the parallel is 0,0070A. 7mA
If you replace one of the pots with 2 times 2.2K, it makes 4.4K, so, then we have 6 pots of 5K plus 4.4K in parallel.. that is 700 ohm
the current is then 0,0071A, 7.1mA.
As you see there is not much difference in current consumption.. I guess 2 times 2.2K is fine then
I would still try to find the 2.7K

João

EDIT: Made a mistake on the calculations Typical with me.. SORRY
The difference is only 0,1mA. corrected now

[Outbreak]

Awesome explanation ! im gone look for 2.7k . hope i can find.. its so hard to find those stuff in my country i asked many places but all i could find is 2.2k.. but didnt ask more then 2.5 so mybe they have.. i will see tonight Tnx alot

[Outbreak]

I found 2.7k and made it.. switch is working awesome.!! tnx alot jhsa

[jhsa]

wonderful..
Have a beer..

[omegamanuk]

Outbreak, any chance of posting a photo of what you have done?
I need todo this for my FY31AP which needs 2x 3 position switches.

[omegamanuk]

Ok got some 2.4k resistors and a couple of three way switches and followed the dig above and sucess!! Had my douts as when I switched on although the display screen showed the switches functioning , when I tried my plane it was dead, whiped the radio in bits and tried the connections to the FRSKY module and its all working may resolder those just to be safe. Thanks for the help youve all posted.
As a picture paints a thousand words here you go.

[alib]

are you in the uk? if so, where did u get the resistors from?

[omegamanuk]

Yes from uk , got the switches and resistors (2.4k) from maplin

[Rob Thomson]

I have suggested a feature on open9x to allow you to swap P3 with a switch.. In this fashion.

The idea being that you loose P3 on the mix list, but gain 3POS2, ID3, ID4, ID5

This bin theory could make programing easier as you do not then need multiple custom switches!

Sent from my Nexus 7 using Tapatalk 2

[Kilrah]

Just a thing, P3 is the most conveniently placed when you need to use a pot... So it would be wise to rather sacrifice one of the other 2

Sent via mobile

[Rob Thomson]

No issue to me which one....

I suggested P3 because it was the simplest to drop off the list of mixes.. without noticing it missing

Maybe a feature could be to allow the user to set the pot to use for 3POS2 ?

Rob

[hobeeami]

Works great. I needed a 3 way switch to setup the bank options on an IKON FBL control.

[KanishkaRC]

hi,

I had a quick look at the code and I guess open9x should work without having any modification with this configuration, only thing needed is simple display option as I understand. but first off let me admit I am not a pro..

as in code,
int16_t getValue(uint8_t i)
{
/*srcRaw is shifted +1!*/

if(i<NUM_STICKS+NUM_POTS) return calibratedStick;

and according to the feature list,
new source in Mixers: 3POS which returns -100% / 0 / +100% depending on the 3 position switch of the 9x

just to check this hypothesis can anybody who had done this hardware modification, pls check this hex file to see whether it works as it supposed to be ?

only mod is P3 now shows as 3P... which means 2nd 3 pos switch..