Converting SuperSimple 50Aamp ESC from PWM to TWI/I2C

[agressiva]

I started this thread because i think lots of people like to use a supersimple 50amp in your MikoKopter or UAVP.

This ESC is very cheap and stronger.

It use a new topology (only N channel fets) and a voltage pump.

With this features the ESC do your job very cold.

Sorry by my poor english

[Arthur P.]

@Aggressiva, the processor side looks suspiciously identical (other than 1 vs 2 caps) to that of the TowerPro 50A ESCs (http://www.rcgroups.com/forums/showthread.php?t=774524&highlight=towerpro+50a). Going to be interesting to see how different the conversion is.

[agressiva]

@Aggressiva, the processor side looks suspiciously identical (other than 1 vs 2 caps) to that of the TowerPro 50A ESCs (http://www.rcgroups.com/forums/showthread.php?t=774524&highlight=towerpro+50a). Going to be interesting to see how different the conversion is.

YEs ... its suspiciosly identical.

The diference is the 3 resistors that are removed.

I dont understand way the towerpro have the 3 resistors connected on pin 14 of microcontroller and "low in" of 2103 .

I think this is for protection os break function.

In the next post i put the image of MODed ESC.

This the same mod of towerpro 50amp that you published.

[agressiva]

this the picture of necessary modification on hardware.

Need to cut 2 tracks and make one wire-up.

[agressiva]

@Aggressiva, the processor side looks suspiciously identical (other than 1 vs 2 caps) to that of the TowerPro 50A ESCs (http://www.rcgroups.com/forums/showthread.php?t=774524&highlight=towerpro+50a). Going to be interesting to see how different the conversion is.

The big deference is that SuperSimple use the max662 (charge pump) to generate 12volt that is used to trigger the fets.

Another difference is that SuperSimple use a 8mhz microcontroler.

The question is ... way de SuperSimple have the crystal if it use internal oscillator ???

Well, i start to modify the firmware.

[Arthur P.]

Interesting difference. I only cut the leftmost track in your picture as that already disconnects the resitor network from the SDA/SCL pin and then the same replacement wiring to the new pin.

[Hell-e-Guy]

Hi Guys,

I'm able to follow the schematics, but I need some help on what R21,R22 & R23 do.
I see that they connect to the comparator input of the MCU.
At first I thought they may be used for over current detection, but this is not a shunt connection?

What's their purpose?

Hell-e-Guy

[MGeo]

There look to be some issues with the schematic, which notes that the MAX charge pump needs schematics. The two large supply side caps are shown on the output of the MAX622. The photos show it across the input leads. Also, the schematic shows them as 100nF, they look to be larger value.

[agressiva]

There look to be some issues with the schematic, which notes that the MAX charge pump needs schematics. The two large supply side caps are shown on the output of the MAX622. The photos show it across the input leads. Also, the schematic shows them as 100nF, they look to be larger value.


MGeo, i am not put the schematic around the max622 because it uses the schematic sujested by datasheet.

if any one need the complete schematic i can finish this.

The interesting schematic for conversion is the part around FETS and MICROCONTROLER.

I take my attention for this part.

regards.

[agressiva]

There look to be some issues with the schematic, which notes that the MAX charge pump needs schematics. The two large supply side caps are shown on the output of the MAX622. The photos show it across the input leads. Also, the schematic shows them as 100nF, they look to be larger value.

By the way, you can look ate schemtic of towardpro 25amp new model that i publiched in another thread.

The schematic around the max622 is the same.

[agressiva]

Hi Guys,

I'm able to follow the schematics, but I need some help on what R21,R22 & R23 do.
I see that they connect to the comparator input of the MCU.
At first I thought they may be used for over current detection, but this is not a shunt connection?

What's their purpose?

Hell-e-Guy


Well, the exact function of this resistor i cant tell you ... but its not for current measure.


This resistor´s are used for receive feedback from fase a,b and c.

[Hell-e-Guy]

What confuses me is that I see the voltage divider from each phase routed to the ADC inputs to check for VCC/2 on the floating phase, but the same nodes is summed and routed to the comparator input.

Hell-e-Guy

[MGeo]

By the way, you can look ate schemtic of towardpro 25amp new model that i publiched in another thread.

The schematic around the max622 is the same.

Found it, thanks.

[agressiva]

@Aggressiva, the processor side looks suspiciously identical (other than 1 vs 2 caps) to that of the TowerPro 50A ESCs (http://www.rcgroups.com/forums/showthread.php?t=774524&highlight=towerpro+50a). Going to be interesting to see how different the conversion is.


Arthur, i found another BIG diference.

The SuperSimple use ir2101 and towerpro use ir2103

[yellow_submarin]

Yes, this was the problem ... The motor would only spin shortly but with the new firmware everythink is ok, there is insane power with kdl 40a motor and master airscrew gf 10*8 propeller. Both motor and esc run really cool, below 30°C and one motor would be enough to lift up the machine with the 4s a123 battery pack ... Need to buy some more escs, one burnt during tests. I'll post a video when finished. Mods are pretty easy and take a few time. I used arthur's parallel interface with ponyprog, there are only 5 wires to solder to the microcontroller to reprogramm. Though i'd like to fond a way to build a more convenient interface like somebody tried to do with a composite paste ... Maybe epoxy would do the work ! I'll try to work something out this evening. Thanks to Eduardo for helping me doing this conversion !

[Arthur P.]

I gave up on the "push on" programming adapter. It is very difficult to get an exact fit. Different ESCs have different amount of space around the processor. And once the SDA, SCL and rerouted phase measuring wires are soldered on they tend to not fit anymore. The programming wires are quite easy to solder on to the processor. What I now do is lave a 6 pin femal strip connector on the ESC. IT adds very little weight. It is held in place with hot melt glue. Epoxy or maybe silicone glue could also be used I guess but would be even less reversible. You only need 5 or 6 pinpricks through the heatshrink to get to the adapter. Works like a charm. Here are some pics of how that looks. And here are the pinouts I use:

Pins on servo lead:
1 SCL White/Orange
2 SDA Red
3 GND Brown

Pins on 6 pin programming connector
(1 = power in side of ESC)
1 SCK Blue
2 RST Green
3 MISO Orange
4 5V Red (not really needed BTW)
5 MOSI Yellow
6 GND Brown

@Aggressive, will you post the sources for this 50A firmware version ?

[Cesco]

@Aggressive, will you post the sources for this 50A firmware version ?

May i join this question ?
A "fliying 40a" esc i got for cheap looks very much the same. Would be intresting to play with the firmware.

Another question: I guess the code protection fuses will be set. Is there a special way to clear this fuses or can the isp programmer handle this ?

[agressiva]

May i join this question ?
A "fliying 40a" esc i got for cheap looks very much the same. Would be intresting to play with the firmware.

Another question: I guess the code protection fuses will be set. Is there a special way to clear this fuses or can the isp programmer handle this ?

Cesco, erase all flash and the fuse bits will be clear.

can you put some pics of this esc ?

[Cesco]

can you put some pics of this esc ?

It's from dealextreme. 17$ incl. shipping.
Backside has 3*4 rows of fet's.
The red cable is for bec and is not original.
Are u using the quax firmware ?

[agressiva]

It's from dealextreme. 17$ incl. shipping.
Backside has 3*4 rows of fet's.
The red cable is for bec and is not original.
Are u using the quax firmware ?

CESCO ... take care with your ADAPTED BEC ...

this make the 7805 too warm and the ESC may stop work in the air

i not recommend this .

about the firmware ... yes, i modified the QUAX firmware.

[Cesco]

Yes, thanks.

I am aware of the thermal limitations of the 7805. I do test motors with this esc, and the bec does only power the receiver.

btw the original belt-cp esc has 2 of those chips inside, and on 3S it gets so hot it will do a thermal shutdown after some minutes. I was shoked to see an RTF heli with this kind of problem.

Even my bl-converted DF4 wil start wiggling its tail after 25 mins of hoover, and i think it's also the 7805 heating up the gyro. seems the DF4 was no build for the 30min flights i make :D

[Arthur P.]

I-m perfectly happy with the UBECs from HobbyCity. No heat and you can get rid of all those 7805 based BECs which cause more problems then they're worth.

[agressiva]

I-m perfectly happy with the UBECs from HobbyCity. No heat and you can get rid of all those 7805 based BECs which cause more problems then they're worth.

Arthur, what model of HC ubec you use ?

Cesco, i crashed my Belt cp 2 times because i used the original ESC ... peace of shi... ESC...

[Arthur P.]

Currently the 3A Turnigy (max 5A) low noise ones.

[Cesco]

I put a bigger heatsink on the belt-cp esc and i did grind the 7805 and fets to same level (height). It doesent really help, the esc will not go in thermal shutdown any more but still gets awfully hot.

No crashes yet, i only do low-lever hoover :) I'm old so it takes a while to learn.

I ordered the switchmode bec from DX. 3A/5A for 10$ last week.

[yellow_submarin]

Hi all
Well, the first esc works fine, but the problem is that all others don't ... The first uses an atmega 8 8, while others use atmega 8 16. Eduardo told me doesn't make any difference if the osc is properly set by using a script to reprogram. However, it doesn't work, and the motor runs as if a phase was disconnected. Does anyone have an idea ?
thanks

[Arthur P.]

Hi all
Well, the first esc works fine, but the problem is that all others don't ... The first uses an atmega 8 8, while others use atmega 8 16. Eduardo told me doesn't make any difference if the osc is properly set by using a script to reprogram. However, it doesn't work, and the motor runs as if a phase was disconnected. Does anyone have an idea ?
thanks

Which ESCs are these? And wouldn't you be able to set the clock of the 16MHz ATMegas to run at 8MHz using the fuse bits? I can't imagine a manufacturer working with different clock speed processors if that requires different programs. However if he can use the same program, only needs to set fuse bits differently, then buying whichever batch of processors he can get cheap makes sense.

[quax]

I've read somewhere, that ALL Atmega8 types are produced without any difference. Means, that normally the chips work from ATmega8L to ATmega8-16 range. There are no good boxes and bad boxes, means, that chips, that are tested for ATmega8L specifications and didn't match, are not furthermore qualified and -for example- sold as normal ATmega8 chips.

The chance is very high, that the chips fulfill all specs and therefore some BLCs have a ATmega8-8 with an 16MHz resonator. You can run the chip with 16MHz without becoming nervous.

cul
quax

[yellow_submarin]

Hi
I'm trying to get these things finally work ...
The fuses I set are sut0, cksel3, cksel1, cksel0.
There's a line in the script which should set the frequency :
READ-CALIBRATION 0x21FF DATA 3 # <EEProm 8Mhz

Can anyone tell me if there's something missing to maje these atmega 8-16 work at 8mhz ?

I have tried programming with a different frequency (data 2 for instance, don't know what frequency it corresponds to) and it is still the same.
I finally doubt that the problem comes from the frequency.
The motors runs as if a power line was missing, just like on my towerpro 40a, except the atmega8 8 ss50 version works, atmega8 16 ss50 don't. Eduardo it could be a problem on the feedback line, but I can't spot any problem on both escs.
What the hell, on either towerpro 40a or supersimple 50a, could spin the motor as i described ???!!
thanks a lot

ps : when the motor is running with the good ss50 atmega8 8 esc, the voltage between 2 power lines is 5v. With bad atmega8 16 ss50 escs, motor spinning oddly, the voltage is only 1.7-2v. If it can help ...