[hitewill]

I am trying to install a Radiolink SE100 GPS to my drone thats using a Revolution FC.  I went with the GPS/Main port and IC2/Flexi port.  Plugging all the wires into the matching holes I notice Radiolinks SE100 wire legend, theres an CLK wire, and Revo doesnt, they have a SCL pin.   Normally I would just shove the CLK wire onto the SCL pin, but I have found electronics  tend to be unforgiving when you put the wrong wire into the wrong hole.  (Kinda like fist time virgins aiming to low and...) Well sorry got sidetracked.  Long story short is the CLK wire and the SCL pin the same.  Ive tried googling trying to find a tutorial that consists of the 2 exact products running in the GPS/IC2 setup but no luck thus far.

[TheOtherCliff]

Yea, it has an I2C interface for the mags.

If a Chinese document for an I2C interface says SDA and CLK, I would bet large money that means SDA and SCL since the CL in SCL means clock...

So remember that GPS:Tx connects to FC:Rx and GPS:Rx connects to FC:Tx
but for I2C to FC you connect SCL to SCL and SDA to SDA.

Also remember that you may need to put two pullup resistors (say about 2.5k) from SCL to +3.3V and from SDA to +3.3V.  This usually works best done inside the GPS shell, but it can also be done right on the FC since it has 3.3V also.

[hitewill]

Do you have a recommendation on a specific brand of pullup resistor?  I went over to Digikey scrolled down to resistors and clicked made it as far as checking 2.5k.  which tolerance is acceptable or specific power/wattage.   Didnt MaGuyver use a bit of chewing gum wrapper for this once?

I was going thru the docs from the GPS and ran across a parameter I should have stated before i think
Power Supply - 5VDC, Current 50-55mA

[f5soh]

Resistor value is not critical, can be 2.2KOhms and no need SMD.
Old resistor type should be fine, 1/4Watt sized.

Solder the additional pullups between SCL/SDA pads and 3.3v.
Add hot glue to avoid vibration issues and that's all.