Corona 2.4 DIY

If you've been building electronic bits or modifying stuff you've bought then tell us all about it here. A good place to discuss the installation of 2.4GHz DIY modules too.

Re: Corona 2.4 DIY

Postby pm-peixoto » Mon Nov 01, 2010 10:09 am

Hi Bruce,

Why do I need this Schottky diode protection to my corona DIY kit? Could you give me the diode specification?

Regards.

Paulo
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Re: Corona 2.4 DIY

Postby RCModelReviews » Tue Nov 02, 2010 8:52 pm

The PPM signal on the Corona DIY module I saw was fed straight into the microcontroller chip which operates from a voltage of just 3.3V. This means that if you drive it with more than 3.3V you end up placing excessive stress on the protection diodes built into that tiny chip.

Also (from memory) the Corona uses a pull-up resistor on that line so all you need to do is add a diode which will block any incoming voltage but allow the radio's circuitry to pull the voltage down to zero-volts.

A Schottky diode will work but I've found that a cheap signal diode such as a 1N914 or 1N4848 also works just fine in such cases.
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Re: Corona 2.4 DIY

Postby pm-peixoto » Sat Nov 06, 2010 9:47 am

Many thanks about previus answer. I have a Turnigy 9x transmitter and my Corona DIY is plugled directly into radio pins (base module). Is it necessary to instal the diodo or not?

Regards.

Paulo :D
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Re: Corona 2.4 DIY

Postby Marcelair » Sat Nov 06, 2010 9:35 pm

Hello mr Bruce, first post of me here at RC Model Reviews about Corona DSSS DIY 2.4 GHz.

The problem is as such; on October 9, 2010, at www.gooieneemlandvvm.nl one of two planes crashed while one of another Corona DSSS DIY-set was switched on.

Duplicating this event on the ground did work once, thereafter it didn't.

These sets are in radios that use + 8 cells or 3S1P LiPo's. Corona states that initial binding is not be be done over 3 seconds (the transmitter) and if this event
is to happen again, to press the master-bind button for over 3 seconds, to be certain that the ID's are different... (?)

Seems like an identical ID, but what caused it ? Is it the <3 seconds of initial binding ? Or perhaps over Voltage on the PPM board ?

Perhaps interesting to know, what is the total number of ID's on Corona DSSS ? Obviously one Corona DSSS that interferes another raises this question, maybe you've heared
about these problems or have any clue ?

Regards and awaiting your view on this,

Marcel(air)
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Re: Corona 2.4 DIY

Postby RCModelReviews » Sun Nov 07, 2010 6:43 am

Hi Marcel,

I have heard of this event previously -- I don't know how many unique IDs the Corona modules can create but I would think it would probably be a 16-bit number (65535 different numbers) in which case the chances of two numbers being identical at the same flying field is very low -- but not impossible.

I don't think over-voltage would have caused this problem -- but it can cause the Corona modules to overheat which might lead to loss-of control issues. Most newer 2.4GHz modules use a switching regulator that is very efficient and generates little heat -- the Corona still uses a linear regulator that turns the excess voltage into heat so if the input voltage is too high, the regulator itself could overheat and shutdown or suffer premature failure.
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Re: Corona 2.4 DIY

Postby Marcelair » Sun Nov 07, 2010 10:44 pm

Thanks for your reply,

In a field test, two Corona DIY DSSS-sets were besides eachother. One set was switched on, and the receiver was switched on, a few seconds later it responded, so did the other set.

But then, a receiver was switched to on, and the transmitter that didn't belong to that specific receiver was switched on, and the receiver responded... This is about an ID-problem I guess.
This test was hard to re-do afterwards, yet it did work once and a Corona-DSSS crash did happen in that way...

There is some uncertaincy about what to switch on first. Does Corona advice to first turn on the receiver and afterwards the transmitter ?

Regards,

Marcel(air)
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Re: Corona 2.4 DIY

Postby Marcelair » Tue Nov 09, 2010 8:52 pm

A test of two Corona DSSS DIY-sets have been done lately, here's the vid,

http://www.youtube.com/watch?v=4dZ7h_Kn ... r_embedded

Note that this proves some strange behavior of the 2.4 GHz sets, that shouldn't ever happen...

Note: This specific lab-like experiment only worked by binding-rebinding for 50 times, so this may be a chance of 1/50 of a hit or total signal blackout.
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Re: Corona 2.4 DIY

Postby jeffie8696 » Tue Nov 16, 2010 2:52 am

My friend that is installing my DIY kit says it is finished. He had to make a circuit to limit and invert the signal but I understand it wasnt too hard.
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Re: Corona 2.4 DIY

Postby pm-peixoto » Sun Nov 21, 2010 3:11 pm

Hello Mr. Bruce,

I was making some investigation about my Corona DIY Module, 2 lockouts last month, and I disassembled and mesured the antenna active part from my transmitter and I found 26 mm. Is it correct or not?
Regards.

Paulo
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Re: Corona 2.4 DIY

Postby jeffie8696 » Fri Dec 17, 2010 7:34 pm

It is done. Here is my new radio with a Corona 2.4 module installed. Old yet New. If you ever attempt to do a conversion on a Kraft there are some things to know since they have an unusual system to contend with. My buddy can provide the technical details.
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