Help, anyone with an FMA CellPro/BalancePro serial adapter?

[Neil_J]

Does anyone have one of these??

http://www.fmadirect.com/images/products/1892.jpg

Reason I ask is, I just bought the BalancePro to charge my 6S T-Rex 600 batteries. FMA will be out of these serial adapters for at least a few weeks. This means I won't know how much power I'm putting back into my batteries for a while, unless I can make my own adapter. These batteries cost $300 each :eek: so I _really_ want to keep an eye on them.

So what I am wondering is, what would it take for someone to cut the shrinkwrap and take a few pictures of the board from both sides? I'm basically wondering what if any level-converting chips are on the board, and where the traces go. I'll be able to use my insane engineering skills to figure all this out from two pictures :roll: I just need the cooperation from someone out there who has one..

Thanks in advance

Neil

[kamtsa]

Here it is (see attached iamges).

Probably a TTL-RS232 level shifter.

Let us know what you find ;-)

Kam

[Neil_J]

Here it is (see attached iamges).

Probably a TTL-RS232 level shifter.

Let us know what you find ;-)

Kam

AWESOME :YeaBaby: :noteworthy:noteworthy:noteworthy


Much thanks, I'll see what I can come up with.

[Neil_J]

OK this is what I come up with...

http://www.helifreak.com/attachment.php?attachmentid=30181&d=1194446666


Seems to be a bidirectional interface, the optoisolator keeps the transmit / receive lines seperated.

I have all the parts available at home, leftover from other projects... shouldn't take very long to put it together.

[kamtsa]

OK this is what I come up with...

http://www.helifreak.com/attachment.php?attachmentid=30181&d=1194446666


Seems to be a bidirectional interface, the optoisolator keeps the transmit / receive lines seperated.

I have all the parts available at home, leftover from other projects... shouldn't take very long to put it together.

Interesting, the Data From PC does not have returning ground. I wonder how it works.

Also, resistor value of 103 means 10K, right?

Kam

[Neil_J]

Interesting, the Data From PC does not have returning ground. I wonder how it works. Also, resistor value of 103 means 10K, right?
Sure it does :lol: , ground is on pin 5:

http://www.balances.com/scientech/imgs/rs232connector.gif


Edit: yes 103 is 10k

[Neil_J]

Also, it seems that someone on RCgroups previously reverse-engineered it:

http://www.helifreak.com/attachment.php?attachmentid=30200&d=1194458914

Not sure who is correct on the RS232 pin connections but I will find out..

[kamtsa]

Also, it seems that someone on RCgroups previously reverse-engineered it:

http://www.helifreak.com/attachment.php?attachmentid=30200&d=1194458914

Not sure who is correct on the RS232 pin connections but I will find out..

I checked the 9pin connector with an Ohmeter and this hand draft seems to be correct. 10K resistor goes to pin 7, opto coupler pin 4 goes to pin 2 and opto coupler pin 5 goes to pin 4.

Now I can see how it works. This is a unidirectional isolated link, the output levels from the charger is 0 - 3.3V so they use the voltage regulator. Pin 7 provides the RS232 '+' level (with a 10K pullup) and pin 4 provides the '-' (when the opto coupler is on).

Not as fancy as Castle Link but works (if you have a free serial port on your computer).

Charger must be transmitting its state continuously.

Kam

[Neil_J]

I checked the 9pin connector with an Ohmeter and this hand draft seems to be correct. 10K resistor goes to pin 7, opto coupler pin 4 goes to pin 2 and opto coupler pin 5 goes to pin 4.

Now I can see how it works. This is a unidirectional isolated link, the output levels from the charger is 0 - 3.3V so they use the voltage regulator. Pin 7 provides the RS232 '+' level (with a 10K pullup) and pin 4 provides the '-' (when the opto coupler is on).
Yep.. wouldn't have been how I implemented it... They are bit-banging the DTR/RTS lines which is usually a no-no (Windows cannot guarantee timing although most of the time its ok).. the RX/TX lines on the other hand are buffered in hardware (at least 16 bytes/characters), so almost zero chance for a character's bit timing to screw up... Maybe a gap between characters but definitely not a pause in the middle of a character. Either way it works, I'll shut up and get my battery charged :)