RC switch question

[aragon]

Hi,

I've searched this group and have found a lot of projects to help me make my own RC controlled switches. One thing I'm not 100% clear on is the following...

I'm wanting to put switches in an RC heli. I'd like the switches to be triggered in conjunction with different throttle levels from the receiver. Is it safe to connect a receiver's throttle channel signal line to multiple devices? Is there a limit of devices you should split the signal out to? I'm thinking along the lines of connecting 2-3 switches to my throttle channel signal line along with my ESC. Can this do any damage to the receiver? Any precautions?


Thanks,
Aragon

[aragon]

Just to follow up... ultimately I just want to achieve multifunction switching from one RX channel. Most of the RC switch projects I've seen only switch one function per channel. Is there a better way of doing this than wiring up multiple switches to a single channel?


Thanks,
Aragon

[pic man]

are you trying to decode the signal sent to throttle servo, and apon different positions cause a different thing to occur?

for example turn signals?

[aragon]

Yes. :)

[pic man]

ive designed a board the size of a futaba reciever which does turn signals and brakes, and various other functions threw different progrming of the PIC used,

do you have pic knowledge,

a programmer?

a compiler?

is this for fun ( learning) or do you just want it cheep?

if you have some knowledge, programer and compiler, i can show ya how i made it work, and how to zero in your "switches"

[aragon]

I love learning, but I find little free time these days and unfortunately it's not closely related enough to what I do for a living for me to spend time at work on it. I'm a programmer yes, but my C knowledge is limited. I don't have pic knowledge or programming equipment, but I know someone that does.

If I could buy a product that makes it easier that'd be ideal. I guess that's not really possible when it comes to PICs. Is it possible to do anything similar with flipflops?

Electronics is an avid sideline interest for me so I'll learn about PICs one day. :)

[pic man]

well, perhaps you could adapt a design threw using my board ( in bout a week ill have it tested and "aproved") and goto yer buds house to arange the program, since you have a heli, im not sure and cant exact what parameters to set as "switches" BUT i can give you a program to use as a base ( which is self explanitory) in pic basic (youll pick it up so easy if u know c) then craft a set of light leads and begin ground testing to figure out your parameters,
your friend can burn and reburn your results drop chip in and test,

i say itll be tested in a week, cause i plan to do some test as to battery consumption battery life etc, ive got it breadborded, working but using 2 supplies, once i get the resanators and solder them on ive got 2 working boards, using one supply, the "craft" reciever pack, blah blah im waiting on parts to build final prouduct, 1 week

to be honest this is a great way to learn in your givin situation, having programing knowledge, acces to a programer, ( and some possibly free software to aid ya)
i think with a circut to work off of and only parameters to define, and leads to make, cost about 15 to 25 $ , after having the board, pic (4 - 6 $) , and yer budies programer (of compatible with 18 pin dip 16f84 ask him)
youll spend a while figuring out where you want "switches" but i can give ya a chart of what my readings are,

is it a futaba or similar am style controler? ill have to make sure your encoding is similar ( i havent goten into pcm etc, or even fm, not sure if the decode system is the same) cant test what i dont have ya know, and had no reason to research it till now

[aragon]

That sounds like a great way to experiment for me, yea. I'd love to see your work!

I'm using Futaba FM/PPM here. Isn't the servo signalling the same regardless of radio modulation? Are you building your own receiver?

[pic man]

ya know, im totally self taught, im realy not positive , as my nexus 30 is with out radio, all i have to tinker on is a standard am futaba / novak reciever, yes its quite reasonable to think they are the same, but it is also posible that with different radios they might be slightly diffeent, ( hopefully some one has done this for fm/ppm and can tell us,

heres the basic lines needed,
_____________________
ste var word 'declare var for steering chann
gas var word 'var for throttle


loop:
pulsin porta.1 , 1 , ste ' check signal from steering channle, pin 18
pulsin porta.0 , 1 , gas ' check signal from gas chammle , pin 14
gosub dir
gosub brk
pause 250

goto loop

dir:
if ste = x then goto "NEW SUB ROUTINE" ' NO "" AROUND SUP ROUTINE, WHERE X = THE POSITION THAT EFFECTS DESIRED SERVO MOVEMENT
_______________
THIS IS THE BASIC PROGRAM FLOW, showing only the sub routine for stering, the board i designed, has 2 channles, at least for am ,, its posible to graph servo movement for example < 300 = no signal, and i believe about 730 is one turn, lets say left, between like 350 and 715 is right turn, reguarding servo horn for turns, for my aplication it directly translates to right turn or left, yours may be roll left , tail rotor left, or some other function, depending on what channle u put it on
if you look up a data sheet on pic 16f84a, it willshow you a pin out of the chip used,
if you get the pic basic manual, it will show you minimum configuration to run a chip, and explainition of pic basic syntax ,
trying to find a way to get you a schmatic ofthe board, the aplication i used to create it didnt alow me to make a jpeg for instance,

[aragon]

I've kept quiet because your last message was mostly beyond me. :) I'm interested in how your project goes though and I'm going to have a look at the 16f84a. Thanks!

[pic man]

alright, i gotta head to work in like 4 mins, ill talk to ya tonight, i have some stuff u should read :)

[vintage1]

If you are selling tiny boards that I can plug into one or more receiver chanels, and write my own Assembler on a PC and downlaod into it, I am interested.

I want to make WWI engine noises and machine gun noises. ;)

How many outputs does the PIC have, and are they analogue or digital...


...and I just sold my textbooks on digital filters too...:D

[pic man]

pic 16f84a 04/p

curently, the board is 1 x 1 1/4 ,
hand made,
curently set up to hook up common ground, seprate + , led leads, using one futaba style conector, there are 4 seprate conectors like this, for a toatal of 8 leds run,
2 inputs, with pass threw, ( jacks in signal wire from servo, and passes threw to another 3 pin header to alow for futaba conector plug on,

im still waiting on some headers , and resanators , hopefully this payday imma get em,

im sure you could easily hook up a buzzer, and i believe theres like 3 extra i/o pins to use,,
gimme a week or two, i just need to finish the working prototype, so far every thing works using a bs2 to proto type , now im migrating to pic, just a mater of parts / testing it

fyi its not a pcb but rather layed out on a uni board, special effort put into making it fit into a rciever sized package

[pic man]

aragon hit me up on yahoo when ya get home , i got some literature to pass along to ya,, imma be practicin my games i play,, ( imma big computer game nerd,)

screen name = jutsuju

[aragon]

Do you use Yahoo only? I have difficulty getting connected with anything but ICQ, but I'll give it a try.

Just found a DIY programmer circuit for that 16F84 pic:
http://myweb.absa.co.za/eric.brouwer/electronics.htm

This is great. :)


Aragon