Hi All,
Just wanted to thank all the contributors to this thread for the help and advise. Using the information posted by Arthur and Agressiva in particular I have modified my TowerPro 18A to i2c without any problems at all! I built several parallel port programmers but Agressiva's design was the most reliable and worked with both PonyProg and AVRDUDE (two programs I have never used before but I also enjoyed the learning curve trying to understand what I was doing!) and managed to reprogram the Atmega chip first time.
I wanted to make a test circuit to check the finished modification and was going to use an Arduino but , to be honest, I was struggling to get my head around the coding requirements for the i2c. I them found the post by the chap in Poland (somewhere around post 504 I think) who had designed a test circuit using an atTiny26 chip. A couple of evenings later I had built his circuit and using AVRDUDE burnt his hex file into the chip and I had a working test unit!!

I could not have done any of this without the help from the people who take the time and trouble to post their ideas and code on this thread and I also want to encourage anyone who is following the thread but thinking that it is too much work or too complicated - it is both of these but still worth the effort if only for the things you learn trying to achieve the end result!!!!!!
cheers

Hi everybody,

I got a handfull of 10A ESCs and wanted to see if I can get them to talk to my MikroKopter. I rebuild Mystery 30A before, so nothing new, right?

Anyway, I removed the shrinkwrap and found a layout I have not seen in any forum before:





It looks like the two I2C pins are not used on this layout. My multimeter says the same.
[sadly, not the case...]

Did anybody ever stumble over this layout? Any experience to share?

Cheers,
Tarwin

send me a full schema of this ESC and i make the code or
send me one sample ESC and i make the code and share int this post.

BTW, how much you pay for this ESC ?
regards.

Originally Posted by tarwin

Hi everybody,

I got a handfull of 10A ESCs and wanted to see if I can get them to talk to my MikroKopter. I rebuild Mystery 30A before, so nothing new, right?

Anyway, I removed the shrinkwrap and found a layout I have not seen in any forum before:





It looks like the two I2C pins are not used on this layout. My multimeter says the same.

Did anybody ever stumble over this layout? Any experience to share?

Cheers,
Tarwin

I started tracing the pcb, and found the SDA pin used after all.
I fact, it looks like its the same layout as an Mystery 30A (bl-17a), just without the external crystal.

Nevertheless, modding it to i2c should be easier then the Mystery 30A if it if possible to change ADC4 (SDA, pin 28) to ADC6 (pin 19) in the port definitions.

I propose the following:


Do you know which parameter to change in the asm to make it work on the internal oszillator? I read a bit into it, comparing it to the tp-18a source (without knowing much about assembler), and found that the internal oszillator needs to be calibrated, and some timings changed (halfed). I'm unsure about the POWER_RANGE and MIN_DUTY vars... ?

I found the ESC on ebay:
http://cgi.ebay.de/2X-10A-Brushless-...ht_2638wt_1165
12€ for two including shipping...

I just read out the original fuses with ponyprog:


Any more info needed?

the internal oscilator is configured in fuse bits.

the fuses on the picture are configured to internal .

to make the mod i need full schematic.

Originally Posted by tarwin

I started tracing the pcb, and found the SDA pin used after all.
I fact, it looks like its the same layout as an Mystery 30A (bl-17a), just without the external crystal.

Nevertheless, modding it to i2c should be easier then the Mystery 30A if it if possible to change ADC4 (SDA, pin 28) to ADC6 (pin 19) in the port definitions.

I propose the following:


Do you know which parameter to change in the asm to make it work on the internal oszillator? I read a bit into it, comparing it to the tp-18a source (without knowing much about assembler), and found that the internal oszillator needs to be calibrated, and some timings changed (halfed). I'm unsure about the POWER_RANGE and MIN_DUTY vars... ?

I found the ESC on ebay:
http://cgi.ebay.de/2X-10A-Brushless-...ht_2638wt_1165
12€ for two including shipping...

I just read out the original fuses with ponyprog:


Any more info needed?

Edit: let me check again...

well, use the firmware for tp17 and use the fuse that you sended .

Originally Posted by tarwin

The schematics are identical to these:
http://freenet-homepage.de/alex_konz..._schematic.pdf

Only difference is the missing external crystal.

Yeah, but don't you need to calibrate the internal oszillator in the initialisation? And some wait steps will be twice as long as with the 16MHz crystal...

The internal osc is 8mhz and the code is for 8mhz ! so you not need to modify anything.

when you write the code on microcontroller you need use a ponyprog script that configure the osc call byte.

the script os the e2s file that came with hex code.

regards.

Originally Posted by tarwin

Yeah, but don't you need to calibrate the internal oszillator in the initialisation? And some wait steps will be twice as long as with the 16MHz crystal...

Sorry, i missunderstood you. I was talking about the bl-17a schematic & firmware (the 16mhz model). The TP-18a (8mhz model) has a different schematic... =/

Hi,

It appears that the overheating on these really cheap ESCs is due to shoot-through on the H bridges (cheaper or larger FETs always have higher gate capacitance, therefore take longer to switch on or off). Adding a nop just before each "switch on" of the FETs removes this specific problem.

However, it obviously causes timing issues at higher speeds.

Does anyone have any better solution?

Hello all,

I am converting 4 Turnigy Plush 30A for my mikrokopter and yesteray evening I made a mistake when programming fuses bits on one of them. The result is that the ATMega doen't answer anymore to my USBasp programmer (I use AVR Burn-O-Mat).

I read on forum that this can be solved by high voltage programmming (via parallel programmer as STK500) or adding external clock on XTAL1. As I don't have any access to a PC with parallel port but just USB ports, I planned to go on the second option.

If I undertand the way oscillator work, 3 pins are actives on these :
- VCC - 5V
- GND
- Signal
So the only thing to do is give 5V and Ground from ISP to the oscillator and connect signal to XTAL1.

Does anyone have tried this ? Am I right ?

Thank-you

With external cristall you solve this problem !

Originally Posted by fmelle

Hello all,

I am converting 4 Turnigy Plush 30A for my mikrokopter and yesteray evening I made a mistake when programming fuses bits on one of them. The result is that the ATMega doen't answer anymore to my USBasp programmer (I use AVR Burn-O-Mat).

I read on forum that this can be solved by high voltage programmming (via parallel programmer as STK500) or adding external clock on XTAL1. As I don't have any access to a PC with parallel port but just USB ports, I planned to go on the second option.

If I undertand the way oscillator work, 3 pins are actives on these :
- VCC - 5V
- GND
- Signal
So the only thing to do is give 5V and Ground from ISP to the oscillator and connect signal to XTAL1.

Does anyone have tried this ? Am I right ?

Thank-you

I have just received a 25a and a 30a Turnigy Plush ESCs for converting to IC2. Did you get some of your Turnigy Plush 25a ESCs to work? What software did you use. Any information would be a great help.

Thank you
Larry

Originally Posted by fmelle

Hello all,

I am converting 4 Turnigy Plush 30A for my mikrokopter and yesteray evening I made a mistake when programming fuses bits on one of them. The result is that the ATMega doen't answer anymore to my USBasp programmer (I use AVR Burn-O-Mat).

I read on forum that this can be solved by high voltage programmming (via parallel programmer as STK500) or adding external clock on XTAL1. As I don't have any access to a PC with parallel port but just USB ports, I planned to go on the second option.

If I undertand the way oscillator work, 3 pins are actives on these :
- VCC - 5V
- GND
- Signal
So the only thing to do is give 5V and Ground from ISP to the oscillator and connect signal to XTAL1.

Does anyone have tried this ? Am I right ?

Thank-you

Hello all, as today I seem to have finally a nice flying mikrokopter, I want to share how I did it.

First of all, I first modified Tower Pro 25A : 2 TP25A type 1 + 2 TP25A type 2 from the first order from Hobbycity.

As the result was not good, I ordered 2 more TP25A and luckely, I received 2 TP 25A type 2. The MK with 4 TP25A type 2 I2C modified wasn't flying better than the first try (TP25A type 1 mixed with TP25A type 2).

As the MK behaviour was some shaking and pumping, I thougth it was some bad gyro setting so I tried almost every setting on gyro with no big improvement. The mikrokopter wasn't still flyable

At this step, I was about to give up but some nice poeple on this forum (thanx guys ), told me to give some more tries. And as I was thinking that the problem was TP25A firmware (old 17A firmware) and I saw Arthur P. post about simple Turnigy Plush 30A mod, I decided to order 4 Turnigy Plush 30A for my last try.

This week-end, I successfully modified 3 out of 4 ESC as one got blocked when programming (I will thry to add external oscillator to unblock it).

As I was quite excited to test theses new ESC, I set up the 3 Turnigy Plush (front, back, right) and a tower pro 25A type 2 (left). I started the MK and the behaviour was as with TP 25A

Then I had an idea !!! The MK was very responsive to all axes incuding altitude even if I was on beginner setting so I modified the max gas value from 240 to 130 and tried this setting.
The result has been very good : I have been able to fly the MK on my living room (I have only 2m x 2m free to fly). The I increased max gas until I got again bad behaviour : I stopped at 140.

The only drawback I noticed is that rudder isn't responsive at all. I think I will have to increase rudder setting under Kopter Tool to correct that.

So for all those like me that have trouble setting up well their MK with modified I2C ESC, just try to play with min gas (motor don't start) and max gas (mk is pumping, too sensitive or shaking). It worked for me

Now, I have 10 working I2C modified ESC (1 Tower Pro 17A, 2 Tower Pro 25A type 1, 4 Tower Pro 25A type 2 and 3 Turnigy Plush 30A) ... Maybe I will sell the unused one or build an hexa or octocopter

Next step, I will try to unblock my fourth Turnigy Plush 30A with external oscillator as agressiva confirmed it should work.

And in the mean time, I will do a test fly with the mikrokopter outside