Hi, 

i am trying to complete the I2C Tutorial (https://support.industry.siemens.com/tf/ww/en/posts/simatic-iot2000-with-i2c-expansion-board/155647/?page=0&pageSize=10) with a different Board:

http://www.dx.com/p/funduino-control-i2c-to-gpio-module-red-181699#.WoFqL67iaos

I connected SDA, SCL, GND and 5V but the LEDs dont light up. The Adress is set to 0x20 with all of the three Jumpers on 0. When i try "i2cdetect" it says, "No i2c-bus specified!".

I used the program given in the tutorial (as it is also for adress 0x20). Is that possible or do i need to change something?

Any Ideas where I made a mistake?

Best regards, 
Chris

Did you enable i2c mode on the affected pins via your own program or via iot2000setup?

i2cdetect expects a bus number as paramter. Should be 0, but I don't have a board in reach to check.

Yes you were right, that worked. So that means that adress 0x20 is available via I2C right?
Strange thing is, when i load the sample Programm in the IOT2040 and run it, still nothing happens. 

It's likely 0x20 (you can check what disappears when removing the board).

Possibly, the example program is not compatible with the board. Double-check what I2C commands your board expects and try issuing them.