PIC controller for FMS

[tailwind76]

Can a guy use the pic chip to set up a controller to use FMS?

everything i have read uses the pic 12 and most of the other talk is of the pic 16 &18

Trent

[steve lewin]

Since this isn't about learning PIC or programming languages I've split it out from the "Learning PIC" thread for you.

To answer your question, yes there are many designs for FMS interfaces using PIC microcontrollers. The one that comes with FMS (in Doc/Interface) is one of the simplest. The circuit and code are provided for both 12C508/9 and 16C84 and it includes assembler source. Almost all programmers will write to any of those PICs.

Steve

[simingx]

I've built the one here: http://www.welwyn.demon.co.uk/fms_lead/fms_lead.htm

Works pretty well BUT I think will only work with negative shift transmitters. I tried setting the shift to +ve on my Eclipse and it goes nuts. :D

[navkan]

Since this isn't about learning PIC or programming languages I've split it out from the "Learning PIC" thread for you.

To answer your question, yes there are many designs for FMS interfaces using PIC microcontrollers. The one that comes with FMS (in Doc/Interface) is one of the simplest. The circuit and code are provided for both 12C508/9 and 16C84 and it includes assembler source. Almost all programmers will write to any of those PICs.

Steve


Steve: sorry, I couldn't find your reference to "FMS (in Doc/Interface)" Could you be more specific? Thanks

Fred

[steve lewin]

When you install FMS on your PC you will find the instructions, circuits, code etc required to build an interface have been installed in a folder C:/Program Files/FMS/Doc/Interface.

At least that's true of FMS7, I haven't checked if it's still there in the latest Alpha8 install.

Steve

[OmegaDot]

Information on PIC based serial interfaces can be found here:
http://myweb.absa.co.za/eric.brouwer/interface.htm
I built the PIC 16F84 Version 2.00 and it works great with WinXp. If you go this route, and use the ElCheapo programmer I mentioned in the "Learning PIC" thread, be sure to change the hex file from Intel32 to Intel8 format! IIRC, simply deleting the first line of hex code did the trick.

Also, I redrew the artwork for the PCB layout in AutoCad Lt95 to use the toner transfer method of PCB fab. I can upload the file if you need.

[Hovertime]

Can anyone tell me if I MUST use 5.6v zener (design provided with fms/doc/interface) or can it be substituted with 5.1v, available at radioshack.?
Author says that "component values are not critical" is it true for resistors too or just transistors?
Thanks!

[lovefool]

I have built a PIC to serial interface using the schematic from Eric Brouwer homepage, but I used the firmware that came in FMS software. (He seemd pull his schematic away from his homepage.) The document directory of FMS contains schematic using 12C508 that is very simalar to the one Eric Brouwer.

Hovertime - I used 5.1V zener and it works.

I have made PCB design by eagle software, so if is anyone interested I will post. This interface works on RFG2 using PPJoy software as well.

[Hovertime]

Hey, thanks LoveFool!
I don't need PCB files, since I will build mine inside old GWS TX, using perfoboard and wires.

[Malc C]

I've built my own design of FMS interface that combines Ken and Erics designs and is based on a 12F675 PIC - which works well with Futaba TX's and FMS. (details can be found on my electronics web site www.rc-electronics.net )

However I wouldn't bother with FMS interfaces, I've just built a TX to PC interface using the USB port ( look at this thread on this BB http://www.rcgroups.com/forums/showthread.php?t=306157 ) - this works with Realflight G2 (non interlinked) and FMS. Total cost is about the same as the parts for a serial FMS PIC interface.

[Hovertime]

Thanks Malc C, but my programmer supports only 12C50x and 24Cxxx series chips.
I also have some 12C508 on hand, And I will never buy Realflight;) Better 2 more airplanes with gear;)

[Malc C]

If you want a new programmer thats not expensive the take a look at the spark fun web site http://www.sparkfun.com/shop/index.php?shop=1&cart=127090&cat=1& they do a programmer for $12 that supports loads of PICs inc the 745 chip.

Oh it that is realflight G2 not the older version

[Hovertime]

Thats a great (and pretty cheap too!) programmer, thanks, but I am in the middle of building the PIC interface for GWS radio, using files included with FMS program.

[transcendental]

Hey,
I broke my Realflight G3 transmitter interface. I'd like to make my own serial interface for it, may be using a PIC. Does anybody know the serial packet format rfg3 accepts?

[Bruce Abbott]

Realflight G3's USB interface is configured as a joystick and uses the standard HID (Human Interface Device) protocol.

You can build an r/c to joystick interface with a USB PIC (eg. 18F2550) and appropriate software. Check out the sticky at the top of this forum:-

RC-USB Joystick Files (http://www.rcgroups.com/forums/showthread.php?t=508122)

[Malc C]

Bruce, I'm sure that the G3 interface uses its own protocol as the hardware forms part of the interlink copy protection. If so then the guy asking for the packet data information is trying to circumvent that copy protection.

[Bruce Abbott]

I don't know how the copy protection works, but it shouldn't need its own protocol. Realflight could just check to see if the correct USB device ID is present, or it could interrogate the device (using normal USB protocols) to read hidden infomation.
the guy ... is trying to circumvent that copy protection
Give the guy a break, he's just trying to fix his broken 'interface' :rolleyes:

[transcendental]

Thanks Bruce! I shall read the link ..

I was only wondering if any simple rs232 interface could work with realflight as it does with FMS (as given here (http://www.rc-circuits.com/PIC%20Serial%20How%20it%20works%20FMS.htm)). But with all the copy protection, this doesn't look possible :).

[Malc C]

he's just trying to fix his broken 'interface'

Then why not simply return it via the normal repair chain (dealer / wholesaler or direct to manufacture)


I don't know how the copy protection works, but it shouldn't need its own protocol. Realflight could just check to see if the correct USB device ID is present, or it could interrogate the device (using normal USB protocols) to read hidden infomation.


Have a look at the simulator section of RC groups and you'll soon find that all the top end sims used dedicated interfaces as copy protection for the product. Whilst they may well used standard HID descriptors, they all used their own protocol or algolrythems to encript the packet data. You may also see on that same forum that its quite common for someone with a single post count to post a request for an interface (or software patrch) that circumvents the protection, so forgive me for stating the obvious but this guy did ask for the protocol for the packet data, which would get round this protection.

Of and if you are going to quote me, quote me in the true sence - notice the IF :rolleyes:

If so then the guy asking for the packet data information is trying to circumvent that copy protection.

[transcendental]

Just to make it clear, I do not intend to violate any copy protection. I would have used a DIY rs232 interlink if the program permitted it.