fischertechnik community forum

I had experienced the very same problem and reported it to fischertechnik.

The same caterpillar model with the IR control instead of the Robotics TXT controller works fine.

So the problem seems to come from the Robotics TXT implementation of IR receiver and controller.

Hello Markus: I don't know where and how the pin 9 as power source has originated. I've posted warnings against using pin 9 as power source ( here , there , and there again) and also shared the schematics of the circuit I'm using for testing the I²C port. I think an official statement from fischerte...

Unfortunately, I've experienced many issues with the Bosch sensors BMM150 and BMI160. They are slightly over-engineered. The BMX055 looks like very similar in complexity. If you're looking after an IMU with data fusion, there are two options: Go for the BNO055 . It includes a built-in calculator tha...

You're welcome!

And Node-RED could run on the Robotics TXT directly. No more multiple releases for each OS.

Hello ft-ninja: Congratulations for this very interesting project. Have you considered Node-RED? http://nodered.org/images/node-red-screenshot-sm.png The GUI comes right out-of-the-box and runs on any OS. Node-RED focuses on IoT and is expandable with new functions —or nodes — easy to create. The av...

"Does a 3.3V/(4K7||4K7)~1.4mA current through the two 4K7 pullup resistors of the level shifter causing a ~200mV-250mV drop of the 3.3V high level of the evil Pin 9 already look like an unreasonable stress to this output? Is the gate switching current of the FET negligible?" We'd need to have a loo...

The problem is twofold. Using Serial-TX as 3.3 V power source may interfere with the serial signals used for debugging. No one can recommend using the Serial-TX as 3.3 V power source because of legal consequences. I sincerely doubt that fischertechnik would accept exchanging a defective Robotics TXT...

Hello Karsten:

No problem! Glad to have found a solution.

I'm not the author of the video you're mentioning.

Actually, it prompted me to post my initial comment on this thread.

What AV and BV stand for? Both +3,3 V and 5 V are connected to the voltage regulators. http://embeddedcomputing.weebly.com/uploads/1/1/6/2/11624344/2928811.jpg?298 Connection to GOUND is not required. See I²C Logic Level Converter . Feel free to add arrows to the schematics to identify your question.

Hello Karsten:

I'm not sure to understand your question. The +5 V is indeed connected, using the labels.

Same applies for + 9 V, + 5 V, + 3,3 V, GROUND, SCL5, SDA5, SCL33, SDA33.

Hallo Dirk:

You're welcome!

Maybe publishing the schematics in the next release of ft:pedia would help many ft fans!

Yes, no power supply except the 9 V makes things a bit more complicated; Now, I've designed a very basic circuit for power supply and logic level converter. I've already used it with the Robotics TXT to test the sensors I developed the libraries initially for the RoboTX. http://reivilofischertechnik...

February and Thomas:

Thank you for the details.

Have fun with I²C and the Robotics TXT controller!

Contrary to what has been posted in forum and video , pin 9 of the extension connector of the Robotics TXT controller does not provide +3.3 V and shall not be used as power source. On the video, total power consumption of 8 LEDs at 20 mA each reaches 160 mA. I hope no Robotics TXT controller has bee...