355 replies to this topic

[Aeronut]

Has anyone in the UK put a V3 board together? I have board and PIC on the way, but am struggling to find the semiconductors in small quantities - maybe someone can point me to where I can obtain these parts easily. Thanks!

[Terry]

What parts are you short of?

Terry

[Aeronut]

What parts are you short of?

Terry

I can't find the SDM03MT40D diode packs, the 74HCT02 and the 74HCT221 in small quantities - most places are happy to sell me a reel of them!

[Terry]

Have you tried Farnell and RS for the logic? the diode pack may be harder to find, maybe make it up from single diodes?

Terry

[Aeronut]

Have you tried Farnell and RS for the logic? the diode pack may be harder to find, maybe make it up from single diodes?

Terry

Terry - thanks for the help. I'd tried RS and failed, but just found the logic IC's on Farnell, so at least I know I can get them. Those diode arrays are proving problematical though - will have to keep looking!

[Aeronut]

I'd just like to proffer a vote of thanks to those on this forum who helped me to get my PPM converter built - the last parts arrived this morning (from Farnell) and I've spent half the day straining my ageing eyes to solder on all those tiny SMD parts to Mr. RC-Cam's board. I fired it up this afternoon and it all worked first time! I'm overjoyed, because, now I can fly my MK on 2.4g! For those that are interested, I'm using Jeti Duplex radio and all channels work as they should. So, a big vote of thanks to Mr. RC-Cam, those who helped me source the parts and those who previously asked questions or provided the answers on this forum. If anyone needs some of the SMD parts for their own converter, please PM me, as I have a few left over.

[Terry]

Well done, it's nice to hear of a success.

Terry

[Mr.RC-Cam]

Thanks for reporting your success. Another happy 2.4GHz MK pilot.

It sure would be grand if a PPM board builder documented their effort and posted some reasonably detailed instructions with a few photos. That would remove some of the mystery from the project. I'll agree all the details are in this multi-page discussion, but something a bit more concise would be very nice.

[Maxrr]

Finally got around to sorting and cropping the pics I took as I built my second PPM V3 board.
I hope the pics and captions can act as a building guide as I'm not much of A writer.

http://maxn.smugmug....510493106_RNeuo

Thanks again to Mr. RC-CAM and all who helped develop this.

Max

Edited by Maxrr, 11 April 2009 - 10:26 PM.

[Mr.RC-Cam]

Thanks for documenting the PPM V3 board assembly steps. Nicely done!

[Maxrr]

Thanks.
I was going to post it in this thread but i thought It would be easier with big photo's.
max

[Xygax]

Just a note of thanks for everybodys input on this project.... Built and bastardized...

Alternative application time....

Wireless sim connection for JR / Spektrum.

There is a minor change... C1 needs to be 47n not 22n... (the leading pulse is too short to register reliably with the Phoenix dongle) and the micro isnt required just link pin 1 and 5

Has been tested with an AR6100e and a DX6i so far but i'm sure DSX9's and so on will work OK....

Thanks

Steve

Edited by Xygax, 17 September 2009 - 07:30 PM.

[pashteton]

Where can I find a converter circuit PWM2PPM for Assan X8R 2.4 ???

Edited by pashteton, 27 November 2009 - 01:19 AM.

[LukeZ]

Hi Guys,

I know this is something of an old thread, but PWM-to-PPM is still of interest for many reasons... I was just today looking at the alternatives available and came across this circuit on the Paparazzi wiki site, which seems to be relatively new (v1.0 August 2010):
MeekPE PPM Encoder Board

The design philosophy is strikingly similar to the PWM2PPM board discussed in this thread, with the exception of the failsafe PIC. I have not been able to find any external discussion of the circuit, and the heading on the wiki page says "Preliminary."

Just wondered if this was an off-shoot of the PWM2PPM designed here, or if anyone had any thoughts on it, or would care to compare/contrast it with the PWM2PPM? The description implies it is intended to be a fairly "universal" design, whereas the PWM2PPM design here is really directed at a few Spektrum receivers, though it may work on quite a few others if I were to but try...

What I am looking for is a relatively simple PWM-to-PPM encoder that is as close to being universal as possible (ie, works with the greatest number of receiver types, while retaining the greatest simplicity). I like these "hardware" designs because they can easily be integrated into a larger PCB project. The encoders that use microcontrollers are nice but you can't always get the uC by itself, which makes it more challenging to integrate.


Luke

Edited by LukeZ, 19 September 2010 - 12:15 AM.

[Kilrah]

What I am looking for is a relatively simple PWM-to-PPM encoder that is as close to being universal as possible (ie, works with the greatest number of receiver types, while retaining the greatest simplicity). I like these "hardware" designs because they can easily be integrated into a larger PCB project. The encoders that use microcontrollers are nice but you can't always get the uC by itself, which makes it more challenging to integrate.

Compromises, compromises...

What you lack by using the way described there, is that you're limited to receivers that output servo signals sequentially and in order. Quite a few high-end ones will output simultaneous pulses, or at least in groups of channels. With those, you're out of luck without a microcontroller.

[LukeZ]

Yes, I see you're right, this is true of both the PWM2PPM and the MeekPE. Fortunately I think for my intended use there will not be many high-end receivers being used. DIY Drones has a uC version that is specified to work with even these complicated high-end receivers, though even there it appears some compromises might be made.

I'm going to try the MeekPE and see how it goes.


Luke