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Mr.RC-Cam

RCFS-V2: New FailSafe with Glitch Filtering.

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Can you change the code to put the RCFS working with 14ms (71Hz).

It is difficult for me to accommodate custom code requests (I can't begin to tell you how many requests I get each week). But, I will see what I can do. Tomorrow I'll do my best to pull the source and project files from the archive tapes and load them up. If things go well, I'll post a custom hex file.

Keep in mind that with my limited free time we will only get one chance at this, so cross your fingers!

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It is difficult for me to accommodate custom code requests (I can't begin to tell you how many requests I get each week). But, I will see what I can do. Tomorrow I'll do my best to pull the source and project files from the archive tapes and load them up. If things go well, I'll post a custom hex file.

Keep in mind that with my limited free time we will only get one chance at this, so cross your fingers!

Thank you very much for try!

I am crossing all my fingers! Good luck!

[]'s

Ismael

Edited by iscarelli

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Attached is the V2.01E hex file that has been modified to allow down to 14mS (70ms) frame periods. I have tested it on a typical R/C Rx and it works fine.

Note: This special release, if it works, is not recommended for general public use. It is only for Kyosho Perfex systems that have the unusually high PPM frame rate. Yes, it will work on a normal R/C system. But because of the relaxed framerate rules, it will not be as effective as the public V2.0 firmware release.

Good luck.

rcfsV2_70Hz.zip

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Attached is the V2.01E hex file that has been modified to allow down to 14mS (70ms) frame periods. I have tested it on a typical R/C Rx and it works fine.

Note: This special release, if it works, is not recommended for general public use. It is only for Kyosho Perfex systems that have the unusually high PPM frame rate. Yes, it will work on a normal R/C system. But because of the relaxed framerate rules, it will not be as effective as the public V2.0 firmware release.

Good luck.

Hi!

I am in work now. When go home I will test and post the results.

Thanks again!

[]'s

Ismael

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Hi!!

It's working very well now!!!

Thank you very much for your work, patience and your interest in help!

Very good work!

Later I will post some photos of my RCFSv2.01 working on my car.

[]'s

Ismael

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hi there, today i encountered the following issue.

When i set the tx to full throtlle the fail safe engages and the servo goes back to preset. Every other position before full works great.......

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The allowed servo pulse width is is approx 0.80mS to 2.20mS. Either your Tx's throttle channel is exceeding that, or the PIC's factory stored OSCAL value has been corrupted during programming. Easiest solution would be to use the Tx's ATV mix and reduce the max throttle end point.

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Unfortunattely my tx does not have end point setting ability. I have the kyosho kt-3dx tx and ks-303 servos (older inferno st). Could this be the same case as iscarelli's above where the v2.01 firmware should be used??

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Could this be the same case as iscarelli's above where the v2.01 firmware should be used??

That firmware changed the framerate limit for his very odd Tx. Without o-scope measurements of the servo signal I can't offer advice on what the best solution would be. I'd only be guessing.

Are you sure the PIC's CALIB word was not overwritten during programming?

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When i got the pic i had read it and save the original firmware in it (i guess i did..). Would this be capable to restore it to its initial state? I have just reflashed the pic with the v.2.01 but the result is just the same.... when i have full throttle it just triger the failsafe. I want to also mention that despite that i dont have the voltage detection i have used the 10 k resistor but not the lm also i am using a 17ohm resistor and a 5.1 v zener in order to have the 6v down to 5v while i am givint to the servos directly 6v. When i am measuring the voltage across the pic i have 5v during normal use or idle but it goes down to 4,3 when full throttle and bact to 5v when the failsafe engages and the servo goes to its preset position...

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When i got the pic i had read it and save the original firmware in it (i guess i did..). Would this be capable to restore it to its initial state?

That depends on the programming system. I would try a new (unused) PIC and ensure that address 2008h has not changed after programming.

... i am using a 17ohm resistor and a 5.1 v zener in order to have the 6v down to 5v while i am givint to the servos directly 6v.

The stability of the PIC's oscillator is affected by the applied voltage. I don't expect this is causing your problem, but it is hard to say. What size/type caps did you put on the PIC to filter the zener's voltage? Perhaps you should try it with a stable 5V supply and see if that helps.

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I am going to order a new pic today. (unfortunattely it takes around 7 days to arrive.) I have not used any other caps except the one in the schematic, do you suggest i should (and if i should would it be possible to tell me what kind of capacitor do you recomend and where to connect it)

Another odd thing i have discovered using a friends futaba (low end model and old) is that while using the same crystal the movement of the servos are smaller even is the tx settings are at their maximum level in comparison with my kyosho. As a result the failsafe never engages.

Do you think that the failsafe may engage because the servo reaches its end with my tx and it might be pushing out of its limit? When the servo reaches that point the power falls to 4,3V...

Does it matter that i have given power directly to the servo from the rx and not from the failsafe? (i have only used the pulse and ground from the failsafe).

Edited by cdrov

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I have not used any other caps except the one in the schematic

Your simple zener supply also needs a larger cap on the PIC's power pins to help reduce voltage ripple. I suggest 470uF. The .1uF must remain installed.

Do you think that the failsafe may engage because the servo reaches its end with my tx and it might be pushing out of its limit?

As explained earlier, the RCFS-V2's allowed servo pulse width is is approximately 0.80mS to 2.20mS. If your servo signal exceeds this allowed range then failsafe will occur. These limits are very generous and exceeding them would not occur in a properly setup R/C transmitter. There is a chance your Tx has a problem in this area. If this is the case, then a new PIC will not help.

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Your simple zener supply also needs a larger cap on the PIC's power pins to help reduce voltage ripple. I suggest 470uF. The .1uF must remain installed.

As explained earlier, the RCFS-V2's allowed servo pulse width is is approximately 0.80mS to 2.20mS. If your servo signal exceeds this allowed range then failsafe will occur. These limits are very generous and exceeding them would not occur in a properly setup R/C transmitter. There is a chance your Tx has a problem in this area. If this is the case, then a new PIC will not help.

Can you please tell me how to connect the capacitor (series parallel on the existing where??????)

I gave a stable power on the circuit but nothing happened....

I will call kyosho tech in order to ask them about the frame rate...

Where should i give on the PIC's firmware relaxed instructions to check what is going on..

Edited by cdrov

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1. The additional cap is parallel with the .1uF ceramic that you have already installed. These caps are directly across the PIC's power pins.

2. I suppose you mean that it did not help.

3. I don't believe this is a frame rate issue. It is most likely a pulse width issue, which is not the same thing. The pulse widths must not exceed the range I mention before.

4. It's not quite that simple. Changing the pulse decoding behavior will require modifying the code (and full knowledge of the bad servo signal's characteristics). However, I just don't have the time to create custom firmware for misbehaving R/C systems. Keep in mind that the existing chosen specs are extremely wide to allow any sane R/C system to work.

It would be best to measure your servo pulse width with an o-scope to determine what is going on at full throttle. I think you will find the servo pulse width is out of specification. A mechanical or electrical adjustment to the Tx's full throttle pot position may solve this. Doing that would be up to you since I have no experience with your system.

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1. The additional cap is parallel with the .1uF ceramic that you have already installed. These caps are directly across the PIC's power pins.

Thecapacitor should it have polarity?

2. I suppose you mean that it did not help.

Unfortunattely yes

3. I don't believe this is a frame rate issue. It is most likely a pulse width issue, which is not the same thing. The pulse widths must not exceed the range I mention before.

4. It's not quite that simple. Changing the pulse decoding behavior will require modifying the code (and full knowledge of the bad servo signal's characteristics). However, I just don't have the time to create custom firmware for misbehaving R/C systems. Keep in mind that the existing chosen specs are extremely wide to allow any sane R/C system to work.

It would be best to measure your servo pulse width with an o-scope to determine what is going on at full throttle. I think you will find the servo pulse width is out of specification. A mechanical or electrical adjustment to the Tx's full throttle pot position may solve this. Doing that would be up to you since I have no experience with your system.

I contacted kyosho today. The tech dept told me that it is impossible to use failsafe on their systems ????? In order to use the o-scope do i have to disassemble my Tx or it is possible from the antenna...

Thank you very much anyway you are a valuable help to me...

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Yes, Electrolytic and Tantalum capacitors have polarity. Just match the cap polarity to the PIC's power pins.

The oscope is used to measure the rx's throttle servo signal (first remove the RCFS-V2). It is the white wire on the Futaba servo cable. Using an o-scope requires experience, so get some help with it.

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Yes, Electrolytic and Tantalum capacitors have polarity. Just match the cap polarity to the PIC's power pins.

The oscope is used to measure the rx's throttle servo signal (first remove the RCFS-V2). It is the white wire on the Futaba servo cable. Using an o-scope requires experience, so get some help with it.

I will do and i will let you know thank you for your valuable help ;)

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I am building the rcfs -v2 and would like to know if it will work with the hobbyking 6 ch rx 2.4ghz . since they use gfsk , i can rely on the rcfs module ,

anyone has tested this on this tx/rx combination.

thanks

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The RCFS-V2 is designed for PPM receivers; it would probably never kick into fail safe on a typical 2.4GHz R/C system.

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The RCFS-V2 is designed for PPM receivers; it would probably never kick into fail safe on a typical 2.4GHz R/C system.

hi

i just finished building the rcfs v2, on the 2.4ghz system from hk in normal mode the servo works fine, in programming mode it stops at step 3, i tried it on my jr fm tx and it works fine, transferred back programmed with preset 3 on the 2.4ghz system works fine to..

does the 2.4ghz rx have different servo pulse rate ?

thanks

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Very strange. I think an o-scope will be needed to determine what is going on with the HK Rx.

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Very strange. I think an o-scope will be needed to determine what is going on with the HK Rx.

do you have a link for o scope or post me a email with the link.

i can take measurements and report them here

thanks

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Lowest price scope on the planet that works well for hobby activities: http://www.jyetech.com/Products/LcdScope/eDSO062.php

Honestly, if you don't already have a scope then just shrug this issue off and continue using your workaround. So, the big question is: does the RCFS-V2 provide failsafe when your 2.4GHz R/C signal is lost? Most 2.4GHz receivers continue to send fake servo pulses, so RCFS-V2 will not recognize that the RF signal is missing. That means it won't work in such situations. That is why the RCFS-V2, and similar commercial products, are promoted for PPM installations only.

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