Open source ESC firmware for F5B - Page 4 - RC Groups
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This thread is privately moderated by jjmouris, who may elect to delete unwanted replies.
Jul 07, 2012, 04:22 PM
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Flash cable

Here is a picture of the cable I use for flashing. As I said earlier, perfect for octupuses. But a fraction of the time trying and failing to solder to the mlf pins.
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Jul 07, 2012, 05:12 PM
Needs to do 52 legs !!
jjmouris's Avatar
Originally Posted by George Shering
Joe, when you are doing test flights could you install a temperature sensor on the motor as well as on the controller. This could be an important check.
I could do, i have checked the motor temp post flight with a temp gun and it's nothing out of the ordinary.

Jul 08, 2012, 01:54 AM
Master of Flash
LazyZero's Avatar

If you send me hex files for the different brake settings. I can add them to the flashtool.

Jul 08, 2012, 02:40 AM
Registered User
Mutchy's Avatar
Hi George and Joe.
Thanks heaps for your descriptions and advice. I'll let you know what chips we have and how we go.
Jul 08, 2012, 10:49 AM
Needs to do 52 legs !!
jjmouris's Avatar
Here are the various brake speed hex files for 2 out of the 3 different versions we have seen.

Would suggest to start with brake speed 5 and then if needed move to 6.

I will try a Hacker 2 pole motor soon and think that for this brake speed 5 should be enough.

Jul 08, 2012, 04:24 PM
Needs to do 52 legs !!
jjmouris's Avatar
Another 3 flights today.

Really pushed it hard, full 1750W.min in 200 seconds and also some 8 leg climbs just for fun. The brake still works perfectly.

Jul 09, 2012, 09:45 AM
Registered User
Keep up the good work guys !!!!
Very interesting

Jul 09, 2012, 10:30 AM
making my own planes...
decones's Avatar
Amazing job guys!
Jul 09, 2012, 02:13 PM
Needs to do 52 legs !!
jjmouris's Avatar
At the field, bigger prop. Sergey 18x22.5" banana. Run time now 28 seconds. This prop never used to brake well. It does now!

Wondering if I should try a hotter motor....
Jul 09, 2012, 04:54 PM
Registered User
Which set up would not brake with this prop before?
What do you mean by hotter? Higher Kv or bigger prop?
Higher Kv with smaller prop normally brakes better. Motor has lower resistance and prop has less torque?
Maybe have to check temperature logs before going lower in number of seconds.
Jul 10, 2012, 05:14 AM
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Mutchy's Avatar
Originally Posted by George Shering
Hi Steve,
Does your green board have an MLF or TQFP microprocessor? One of mine has an MLF chip, as does one of Joe's. Even Simon was despairing at the MLF. Joe managed to solder wires to his MLF, congratulations to him, he shows a picture in post 14. I failed after several attempts and ended up having to pick out shorting solder with a pin.
Only the MISO, MOSI and SCK pins are the problem. The reset pin has a solder pad and the GND is readily available elsewhere.
In the end I made three probe wires by soldering the flasher wires to normal dressmaking pins. Then held the dressmaking pins in contact with the microprocessor pins, easy and clean to do. They make a micro pit in the microprocessor pins which stops them slipping.
If you are an octopus it is then very simple. But I manage to hold the MISO, MOSI pins in one hand once they are firmly place, hold the SCK pin in the other, and get my wife to operate the computer. Fortunately it all seems very robust and the occasional slip is not (so far) disastrous. I don't use the VCC, keep clear of that, my flasher is wired to assume 5V.
I will probably use this technique for the huge TQFP package even though an elephant could cope with them after MLF!
Hi George.
My Red Brick has an ATMEGA8L processor on a green board. The FET's are marked NIKOS P04038BD.(yes that's a 4 not a 6 as in P06038BD referred to in your post on page 1 of this thread) I assume the processor is not MLF as there is no MLF in the name printed on the processor and it looks exactly the same size as Joe's pictures on page 1 of this thread. The full description on the top of the processor is:

It appears that this processor is limited to 8MHz. I am disappointed as I use hacker 2 pole motors and run them at about 10,000 RPM and therefore high commutation rate.

So Is this the ESC where I need to have a fire extinguisher handy?

Last edited by Mutchy; Jul 10, 2012 at 05:15 AM. Reason: typo
Jul 10, 2012, 05:49 AM
Needs to do 52 legs !!
jjmouris's Avatar
Another 4 flights yesterday after nearly meeting up with Eric at Luton airport.

Total now stands at 15 flights.

George, that big 18x22.5 never wanted to brake very well on my other setups like the 3400KV Hacker on 6S with a P180 but then i never tried 'immediate' on the brake settings and that may have done it. I also flew this prop with a Neu 1512/2.5D on 10S with a P85HV and that was awefull in terms of barking brake. Changed that to a B50 13L and suddenly it was sweet. With hotter motor i mean just that, higher KV. This motor i am running now is not a typical motor being used out there, more typical would be a 1512/1.5D and this will put the power up a bit.

Anyway, i am just happy to see the brake work so well and the current run time is very respectable. So we will see later when i reach 50 cycles.

Steve, the TQFP or MLF is not printed on the processor. It's just the name of the type of packedge. MLF is very very small like the one in post #14. The TQFP packedge is simply a lot bigger. The processor is otherwise the same, mine is an 8L also.

Don't worry about the other numbers or any reference to 8Mhz, as long as there is an external oscilator (the 5 layer gold/white thing) you can run it at 16Mhz and the firmware files i posted above will work. Just to be sure you use the correct files, please post a picture of your logic board!

Also regarding the fets, i wouldn't worry to much about it. I have not seen the spec sheet of those but really it's not likely to make a huge difference. Just try it and see. Measure the temperature during flight.

Here are the fet temperature vs W.min used graphs from yesterday.
Jul 10, 2012, 05:57 AM
Needs to do 52 legs !!
jjmouris's Avatar
This is the one i am flying now and it uses the rb70a.hex files.
Jul 10, 2012, 05:58 AM
Needs to do 52 legs !!
jjmouris's Avatar
This is the other one i have with the MLF packedge, no BEC and it uses the birdie70a.hex files.
Jul 10, 2012, 06:09 AM
Needs to do 52 legs !!
jjmouris's Avatar
This is the third option we have seen and it uses the hk200a.hex files, currently not available with the brake settings.

Note that if your ESC does not EXACTLY look like one of these, you should post a picture and/or try to check if it matches any of these pin layouts. You are looking at the connection arrangement between the fet drivers and the processor. It's just the inside 2 legs of the fet drivers.

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