Author Topic: RC telemetry  (Read 1571 times)

E.Walker

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RC telemetry
« on: August 02, 2016, 07:34:53 AM »
Hello everyone,

I'm working on my new project, RC telemetry for my plane / car / boat.

I allready have IISI RC telemetry for my expensive planes (I have a jet with 50V 135A max power setup), but I didn't want to spend 200€ in a second one for small application and for my boat.

I decided to build one, I'm using a current sensor from allegro and 2 moteino 433Mhz.
Just doing the consumption time integration to have mAh and then I send the data to the receiver powered by a 9V battery.

Currently, it's working great, still working on the calibration.
In my car it's reseting, I will add a decoupling capacitor between Vin and Ground as the ground is common with the ESC and a lot of noise maybe comming this way.

I have also a HV version, with a voltage regulator to allow up to 12S lipo setup.

Rgds


TomWS

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Re: RC telemetry
« Reply #1 on: August 02, 2016, 08:18:10 AM »
Neat project!  Thanks for posting!

Re power supply on your car, you may need a series inductor (to filter out HF) and diode with a bulk storage cap (to sustain the Vin during large spikes) on the supply to Moteino Vin to filter out the voltage spikes.

Tom

Felix

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Re: RC telemetry
« Reply #2 on: August 02, 2016, 10:08:00 AM »
Cool, I like how you sandwiched a MoteinoUSB between a battery and an LCD.
I didn't know the Moteinos can *almost* work as an OLED shield ;)
+1 on what @TomWS recommended about the car supply.

E.Walker

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Re: RC telemetry
« Reply #3 on: August 02, 2016, 04:07:10 PM »
! I added a 100F capacitor and I tested it 5 min in the garden and zero reset.

There is no voltage reading in the low voltage version, in the HV version I added resistor to be able to give the watt also on the screen.

I may add 2 resistor in the LV version to add the voltage measurement, once calibration is complete.

I also bought the unidirectionnal version of the current sensor, double sensitivity ....

TomWS

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Re: RC telemetry
« Reply #4 on: August 02, 2016, 06:53:02 PM »
! I added a 100F capacitor and I tested it 5 min in the garden and zero reset.
I'd add the blocking diode also since the bulk cap will drain back into the Car load without it.  With the blocking diode the Bulk cap can probably be smaller since it's only maintaining the Moteino load while the VBat is swinging all over the place.

Tom

E.Walker

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Re: RC telemetry
« Reply #5 on: August 03, 2016, 05:41:36 AM »
I need to do extensive test, but I manage to put the cap below one wire and it does not increase the size !

So if it work like that ... if not I will be back.

E.Walker

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Re: RC telemetry
« Reply #6 on: August 10, 2016, 03:23:04 AM »
Small modifications

I added 2 resistors for voltage readings, I kept the high voltage version ratio even if it gave a very low accuracy for the low voltage range..
But for this application, it will be more than enough.

You can see the first prototype, the HV version, with a 60V input 5V regulator that was expensive ... so I can connect up to 12S lipo (~50V)

It's now time to think of my next order to refund my motieno stock :P

rdgs