Are you using a resistor to avoid spark when plugging battery?

The most critical moment in the operation of the microcontroller is the exact moment it is energized.

 The voltage fluctuation at the moment the microcontroller initializes may induce an error in reading the EEPROM memory where the flight parameters are stored. But this type of error could/should occur in any other flight parameter.

Abstracting the spark at the moment the battery is connected it is difficult to imagine any other possibility other than a failure in the microcontroller.

Same code, same hardware works on hundreds of other devices.

 

Would using a switch in the off position when connecting the battery protect the timer?  I have had several times over the years where the timer did not want to arm.  Switching it off then on again cured it.  Could it have been that I had the switch in the wrong position when I plugged in the battery? 

Ken

When the battery is connected, the ESC capacitors charge suddenly and cause a spark in the connectors, which can cause a voltage fluctuation at the very moment when the program execution is reading the flight parameters recorded in the EEPROM.

Until you solve the spark problem, you can try this: connect the battery and then disconnect it, wait 3 seconds, connect it again and fly. The second time you turn it on you will no longer hear the spark popping. If the problem is actually caused by the spark, this procedure I hope you may solve your problem.

You appear to know a thing or two about the electronics we use.  Does the On/Off switch actually disconnect the ESC internal wiring from the power source and prevent the capacitors from charging?  I suspect not but it might prevent the ESC from reading the EECROM.  Would connecting the arming plug then waiting to turn on the switch help prevent this from happening?  I have been told that I should short out the switch loop and eliminate one source of failure.  I am currently building a Twin and was told to just short out ESC 2.  From what I am understanding from your post either of these may actually introducing a possible failure to arm that by definition would only happen on an official flight.  Am I understanding what you posted?

Ken

In thinking back the only times this has happened to me had the common event of inserting the arming plug with the switch on.  Usually because I forgot to bring it on the circle with me then forgot to switch it off while I went back to my box. ( I also forgot my battery stick a lot when I flew IC)

I asked this question of the Bing AI and here is the answer.  If it is correct, and we know AI is always correct then this fully answers why we should use a switch AND an arming plug.

"The Jeti Spin 66 Pro ESC does not load its CCEROM memory when power is applied with the switch off. The CCEROM memory is typically accessed and modified during the programming phase when the ESC is powered on and the switch is engaged. If the switch is off, the ESC remains inactive, and no memory operations occur."

So Saith Jeti

Sometimes I can't help myself.  This answer led me to ask if the ESC could be damaged by bypassing the start switch and here is what came back again citing Jeti as the source:

"Applying power to a Jeti Spin 66 ESC with the start switch on can potentially cause damage. The ESC is designed to handle specific power sequences, and bypassing these can lead to issues such as short circuits or overloading the components."

FWIW, I have thousands of flights on my 4 Fiorotti timers. I’ve only had the 2 premature ending flights on this one timer. On the ones I am using the Jeti ESC, they both have had the switch removed and the wires shorted together by soldering. My others are with Castle Creations ESCs which don’t use a switch. I don’t use any of the anti spark connectors. IMO, it has nothing to do with the ESCs. It is more like the internal timer is counting wrong and ending prematurely. It does the normal 10 second countdown when the LED pops on and then shuts off normally. If it was an ESC issue, the blue led on the timer wouldn't know to turn on nor is it likely the esc would keep going if it had a problem.
The sparking when plugging in is unlikely to effect the timer as it takes several milliseconds for the esc to boot up and turn on the bec circuitry. By the time the bec boots and provides power to the timer, any spikes or transients would most likely have dissipated by the time the timer itself boots up. It is most likely a problem with this one specific timer of mine and it only happened because I built it permanently into the airframe. Had it been relatively easy to replace, it would’ve never had a problem 😂.
I'm going to fly it a bit more as I have a couple of Igor's lightweight proposals to try out. I’d love to figure out the problem as I truly hate intermittent failures! May try flying some more on Sunday morning and see what happens.

Matt

I had this erratic startup problem on my Timer RC several times when I was testing it. Fiorotti himself helped me to solve the problem by telling me to insert a parameter (PWRTE)  in the source code that makes the microcontroller delay the execution of the program by a few milliseconds.

 If we are ruling out the possibility of a failure in the boot, then the only possibility left is a failure in the microcontroller itself as I commented in my fitst comment.

Hi Matt,
I want to order a C & D timer, can you provid a an on and off switch to with the parts, there is no electronic store around here, it can be a simple slide or push button what ever you have.  I’ll be happy to to pay extra for it.  Thank you for offecting this timer, I’m sure I’ll order more of them, please advise.

Sincerely,
Mike Pratt

Hey Mike, I’m not sure if you posted this in the wrong forum or just have me confused with someone else. I don’t have anything to do with the C&D timer. I have a couple but that’s my extent of involvement with them.

Good luck, Matt

I think you want this thread

https://stunthanger.com/smf/gettin-all-amp'ed-up!/climb-and-dive-timer-revue/

Ken

Odd may not be the right word.  First time in some wind (about 10) since the pancake at the Southwesterns and I had serious wind up.  The boost was coming on late in the loops and not releasing till near the bottom.  I am at a loss which setting I should change.  I am going to re-level the accelerometer just because I can.  G-Force is coming on as it should.  It has been suggested that I lower my low rpm to get more brake.  That makes sense and I will try it next time out.

Ken

Check the value of "C" leveled on the bench then level it in the inverted position, the value of "C" will have to be close.

Rogerio.

I have readjusted x and y to your factory "C" value.  Mine is 408.  I have X at 408 and Y flutters between 407 and 408.  Are the timers and pads susceptible to impact damage. It was performing flawlessly before the pancake crash.  It did really mess up the accelerometer mount but now it says it is flat.  I suppose I should force a recalibration.  How close is "close" on matching the "C" value.  When I leveled the plane on the bench after the session we are talking about here I had an "X" of 411 and "Y" of 403.  Is that "close" or "way off".

Ken


Ken

Guys,

I changed my post above with some information.


Rogerio.