Ppm tester?

Electronic projects that are either related to the firmwares for the 9x, or simply great for radio control applications.
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ShowMaster
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Ppm tester?

Post by ShowMaster » Wed Nov 13, 2013 4:40 pm

Many with loss of ppm tx out or think they do, have no scope to verify it's there.
Anyone see for sale or has built a ppm decoder that takes ppm in and displays it or moves a servo that's inexpensive other than a scope?

Maybe a simple Arduino project that could also be sold PNPlay?
I'm thinking any old component receiver could also be modified to inject the ppm into its decoder section.
The idea is to make it an inexpensive tool for ppm and also trainer out troubleshooting.

Is this something practical to work on?
Ideas if so please.


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Re: Ppm tester?

Post by MikeB » Wed Nov 13, 2013 5:02 pm

It's called a TRAINER CABLE. You switch the Tx on, plug the trainer cable in, then hold the tip of the other end of the trainer cable on pin 1 of the module connector.
You get the first 4 PPM channels displayed at the bottom of the trainer menu.

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davx
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Re: Ppm tester?

Post by davx » Wed Nov 13, 2013 5:08 pm

Hi,

An arduino code for reading PPM signal up to 16 channels : http://code.google.com/p/read-any-ppm/

Tchao

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ShowMaster
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Re: Ppm tester?

Post by ShowMaster » Wed Nov 13, 2013 5:21 pm

Good ideas thanks to both of you.
I never tried mikes idea but it makes sense.
This should be added to wiki as a ppm test mode Mike.
I'll also check out the Arduino link for a decoder.
Thank you.

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ShowMaster
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Re: Ppm tester?

Post by ShowMaster » Wed Nov 13, 2013 5:33 pm

davx wrote:Hi,

An arduino code for reading PPM signal up to 16 channels : http://code.google.com/p/read-any-ppm/

Tchao
Is there a build diagram and Arduino board/part number/schematic along with the code? I'm still new at this but like the project.
Thank you


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Re: Ppm tester?

Post by jhsa » Wed Nov 13, 2013 6:09 pm

since both opentx and er9x display the channels timming on the limits menu, I don't need server testers/cyclers anymore ;).
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Re: Ppm tester?

Post by SkyNorth » Wed Nov 13, 2013 6:31 pm

You could also use the PCs internal sound card for a simple scope
http://www.zeitnitz.de/Christian/scope_en

The key is to use a pair of resistors as a voltage divider , to scale the input so that you keep the Microphone input below 1V

-Brent

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ShowMaster
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Ppm tester?

Post by ShowMaster » Wed Nov 13, 2013 7:28 pm

Thanks Brent. I've been meaning to try the PC scope but I own 4 that range from 20-200mhz scopes now all of a sudden. Pays to hang with us gray hairs as our wives don't want them when we move on to the big hobby shop in the sky!
What's needed is a how to on making the probes or maybe there's some cheap ones already out there. Many don't want to build or don't have the parts. Maybe a eBay gadget item along with the other things created here?
A probe kit or pre built.
How about a cheap 1-1 capable probe with a interface board?
BNC in, 1/8 audio plug cable out?


Anyone reading this ever use a low cost or free PC scope that cares to comment?

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Re: Ppm tester?

Post by Infinity » Wed Nov 13, 2013 7:30 pm

@ShowMaster: have you seen that: http://www.sainsmart.com/sainsmart-arm- ... e-kit.html
Why reinventing the wheel when the chance is small to beat that ;-)
Btw. if you don't like the standard firmware you can get updates and the source code here: http://www.siliconinvestigations.com/Ds ... sonano.HTM
Opensource community is available too:-) Link: http://www.seeedstudio.com/forum/viewto ... 5&start=40
Well, Christmas is coming up, right? I think I'll ask Santa Claus to bring me one :mrgreen:

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Re: Ppm tester?

Post by SkyNorth » Wed Nov 13, 2013 7:38 pm

A x10 probe would be good for logic levels (5V) ( a 5V input would be reduced to 0.5V )
You could make up BNC to 1/8" male plug adapter , or just cut off the BNC and solder on the 1/8" plug directly

Here is a cheap source for scope probes , they have ggod prices on small toggle switches.
http://www.mpja.com/Electronic-Test-Lea ... oducts/57/

-Brent

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Re: Ppm tester?

Post by ShowMaster » Wed Nov 13, 2013 7:44 pm

Infinity wrote:@ShowMaster: have you seen that: http://www.sainsmart.com/sainsmart-arm- ... e-kit.html
Why reinventing the wheel when the chance is small to beat that ;-)
Btw. if you don't like the standard firmware you can get updates and the source code here: http://www.siliconinvestigations.com/Ds ... sonano.HTM
Opensource community is available too:-) Link: http://www.seeedstudio.com/forum/viewto ... 5&start=40
Well, Christmas is coming up, right? I think I'll ask Santa Claus to bring me one :mrgreen:
I've owned and used scopes for years but not new models.
I won a eBay auction for one of these but got the word it was pulled due to fraud so I bought a Rigol 1102e. Then friends died and their wives gave me modern 100/200 MHz tektronix scopes.
I really like the Rigol!
So I never tried another scope purchase like in your links.
Good info for forum members to look into,
Thank you.

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Re: Ppm tester?

Post by ShowMaster » Wed Nov 13, 2013 7:46 pm

Good info Brent. I'm sure many with pulse issues don't know they can make a simple scope for troubleshooting.

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Re: Ppm tester?

Post by jhsa » Wed Nov 13, 2013 8:03 pm

I just had to approve Skynorth's post.. :)
I'm sure he has more than 5 posts, so don't need approval :mrgreen:

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Re: Ppm tester?

Post by kaos » Wed Nov 13, 2013 8:45 pm

davx wrote:Hi,

An arduino code for reading PPM signal up to 16 channels : http://code.google.com/p/read-any-ppm/

Tchao
It is interesting. Is there a detail description for how to make this?

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Re: Ppm tester?

Post by ShowMaster » Wed Nov 13, 2013 11:07 pm

jhsa wrote:I just had to approve Skynorth's post.. :)
I'm sure he has more than 5 posts, so don't need approval :mrgreen:

João
Thanks for approving SkyNorth. I thought his post looked unapproved but I was hurrying out.

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Re: Ppm tester?

Post by davx » Wed Nov 13, 2013 11:10 pm

ShowMaster wrote: Is there a build diagram and Arduino board/part number/schematic along with the code? I'm still new at this but like the project.
Thank you
kaos wrote: It is interesting. Is there a detail description for how to make this?
I've not tried it myself but the information are in the sketch comments. I'd assume it's a Uno board and it's really simple, just connect the PPM signal to the arduino and it reports the channels values in the serial monitor.

Good night.

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Re: Ppm tester?

Post by ShowMaster » Thu Nov 14, 2013 3:13 am

I understand. Thanks

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Re: Ppm tester?

Post by davx » Thu Nov 14, 2013 5:36 pm

Hi,
I've just tested the arduino "Read any PPM" code with an D8Rv2 (CPPM firmware) and it works really well.
You have to upload the sketch (obviously :mrgreen: ), connect the receiver PPM signal to the pin 3 of the Uno (don't forget the ground an the power supply) and open the serial monitor where you can see the 8 channels and their respective values in micro second.

Tchao

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Re: Ppm tester?

Post by ShowMaster » Thu Nov 14, 2013 7:00 pm

Good to know it works.
Many without a scope need other inexpensive options to see what's going on.

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Re: Ppm tester?

Post by Andrewjfernie » Sun Nov 17, 2013 10:55 pm

IMG_0257.JPG
I was working on getting my APM with Taranis converted to PPM and came across this thread. I had an Arduino LCD keypad shield in my parts box so created a stand-alone monitor using the "read-any-ppm" library referred to in the thread.

Nothing much to the H/W setup - just wire a servo connector to the pins as shown in the photos (Arduino pin 3)

Use the Up and Down buttons to scroll through the channels

Use the Left button to select a display of the number of channels captured, frame update rate, and two channels. Use the Right button to select display of four channels.

Use the Select button to reset the display.

Also works fine for display of a normal servo control signal.

I have only tried it with positive pulses (normal servo ccontrol and the FrSky CPPM). Not sure if other manufacturers use negative pulses for their equivalent of CPPM.

Zip file of code is attached, or download from https://github.com/andrewfernie/PPMDisplay

Andrew
Attachments
PPMDisplay.zip
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IMG_0259.JPG

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Re: Ppm tester?

Post by ShowMaster » Mon Nov 18, 2013 5:52 am

Really good work. Handy piece of test equipment to make.

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Re: Ppm tester?

Post by Rob Thomson » Mon Nov 18, 2013 7:18 am

Indeed!

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Re: Ppm tester?

Post by kaos » Mon Nov 18, 2013 7:23 am

On my to do list. ;) only 5.xx at ebay with free shipping for that arduino display.

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Re: Ppm tester?

Post by ShowMaster » Mon Nov 18, 2013 8:19 am

Post the eBay link please.

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Re: Ppm tester?

Post by davx » Mon Nov 18, 2013 9:30 am

Hi,

There's a lot of different sellers so just put "arduino lcd shield" in the search field.

Tchao

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Re: Ppm tester?

Post by rperkins » Mon Nov 18, 2013 2:11 pm

I like it.
Thanks for posting

I have a shield and also had to reorder the parameters to LiquidCrystal lcd(8,9,4,5,6,7);
Took me a while to figure that out.
Never played with the input buttons, didnt know they were all driven by one analog input via voltage divider.
See you setup a serial line but arent using it much. Probably doesnt matter on a sketch this side. Probably for debug?
Curious what all the visual studio stuff is in the repo? I havent graduated past the arduino's minimal ide.

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Re: Ppm tester?

Post by Andrewjfernie » Mon Nov 18, 2013 5:11 pm

You would think that they could have got the lines driving the LCD panel the same when they came up with the LCD keypad clones. Guess that is a warning to anyone that tries this to check the data sheets.

Serial line was there in the original read-any-ppm code as the display was via the serial data. I cleaned out the code that sent the data out, but forgot the initialization. It can go.

I use Visual Studio 2012 with the Visual Micro plug-in for my Arduino work. I find it more efficient than the Arduino IDE. If you don't have VS2012 available you can always download Atmel Studio (for free). It is based on Visual Studio 2010 and the Visual Micro plug-in works with it also.

Andrew

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Re: Ppm tester?

Post by rperkins » Mon Nov 18, 2013 6:18 pm

Thanks
I know there is better than the arduino editor/ide.
I just havent gotten that far yet.
I'll keep these solutions in mind

Yes thats why I mentioned the lcd driving lines. It got me

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Re: Ppm tester?

Post by Andrewjfernie » Tue Nov 19, 2013 1:49 am

As mentioned above, there are many sellers for the parts. Here is the first that popped up on ebay for me - never purchased from them, so just treat this as a reference as to what to look for.

You need the basic Arduino: http://www.ebay.ca/itm/Arduino-UNO-R3-b ... e24&_uhb=1

And the LCD keypad shield. http://www.ebay.ca/itm/New-16-2-LCD-Key ... 5e9&_uhb=1

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Re: Ppm tester?

Post by kaos » Tue Nov 19, 2013 2:38 am

would a Pro mini work for this project?

Here is the shield for 5.65 I was talking about: http://www.ebay.ca/itm/111146952781?ssP ... 1438.l2649


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