Also see: en/TowerPro25A2Regler



Converting TowerPro 50A ESCs to TWI/I2C

Changes needed


To convert a TowerPro 50A ESC to allow it to be controled over the I2C (TWI) interface by the flight controler you have to cut two connections on the PCB, to separate a resistor network from the SDA pin, and reconnect the network of three resistors to a different processor pin. In addition you can cut a third connection to free up the orange PWM wire for the servo lead so that you can use the existing servo lead as I2C/TWI cable with an additional GND wire.

Step by step conversion in pictures


http://gallery.mikrokopter.de/main.php/v/tech/CIMG1828_Formaat+wijzigen.JPG.html
One side of a new TowerPro 50A ESC.
http://gallery.mikrokopter.de/main.php/v/tech/CIMG1829_Formaat+wijzigen.JPG.html
Other side of a new TowerPro 50A ESC.
http://gallery.mikrokopter.de/main.php/v/tech/CIMG1831_Formaat+wijzigen.JPG.html
Fully unpacked new TowerPro 50A ESC.
http://gallery.mikrokopter.de/main.php/v/tech/CIMG1833_Formaat+wijzigen.JPG.html
Fully unpacking is not a good idea as the heatsink is held in place with cream and will start sliding, so you will have to tape it in place temporarily.
http://gallery.mikrokopter.de/main.php/v/tech/CIMG1837cut.jpg.html
This is a simpler way of keeping the heatsink in place while converting the ESC.
http://gallery.mikrokopter.de/main.php/v/tech/CIMG1840_Formaat+wijzigen.JPG.html
First part of the conversion completed with the resistor network reconnected to a different processor pin
http://gallery.mikrokopter.de/main.php/v/tech/CIMG1842_Formaat+wijzigen.JPG.html
SDA and SCL pins connected to the red and orange servo leads after cutting the old connection to the orange lead. As far as I can tell at the moment the red servo wire is not connected to anything (these ESCs do not have a BEC).
http://gallery.mikrokopter.de/main.php/v/tech/CIMG1844_Formaat+wijzigen.JPG.html
Programming adapter soldered to the MISO, MOSI, SCK, RST, and GND, and temporary connectors for battery and motor in place, ready for reprogramming and testing.
http://gallery.mikrokopter.de/main.php/v/tech/CIMG1846_Formaat+wijzigen.JPG.html
Close up of the temporary programming connections. I-ve found quickly soldering the wires to the pins or resistors or pads, is as quick as using a programming adapter made from Fimo clay as those tends to be a less then 100% perfect fit.

Final steps in the conversion


Next step is to reprogram the processor, test the ESC with a flight controler and an old motor to ensure the reprogramming went well and the ESC is correctly translating I2C/TWI throttle settings into motor RPMs, remove the temporary programmer wiring, epoxy all other new wiring in place to avoid breaks or shorting out of any wiring, and re-heat-shrink the ESC.



/!\ ToDo: hier gibt es noch etwas zu tun