Hello everyone.
First off all I would to to apologige for such a long writing, but I like to explain every delail on my projects so people can understand why I did the things I did.
I have an Teensy LC that reads 4 sensors and then shows the sensors values in an I2C 20x4 LCD.
The Teensy is powered by 5V in the 5V pin, with the USB line cutted. The LCD is powered by 5V from another power regulator, but grounds are the same.
I had 10K pull-up resistors on the SDA and SCL lines trough 3.3V, everything worked fine on my breadboard.
This is for an agriculture machine and the LCD needs to be apart 6 meters from the Teensy. I only then realised that I2C has distance limitations.
With the 6 meter cable the LCD dind´t work, or random number would appear. I the replaced the 10K pull-up resistor by 1K pull-up resistors, and the systems worked, I even rolled the cable trying to create interferences but the system kept working.
Now is where thing get odd:
I have done all this prototyping with my workbench power supply, an MLINK APS3005S-3D. Once everything was validated, I installed the system in the machine and the 12V power comes from the tractor 12V plug.
For my surprise, the LCD doesn´t show the information, but the Teensy keeps running. For some reason the LCD powered up but it didn´t show information, not even in the previous setup (I suspect that the I2C adapter on the LCD is broken now)
After replacing the LCD I can only get the information if I connect the I2C lines with an 0.1m cable.
Why does it work with the workbench power suply and not with 12V from the tractor? I also tried an laptop power supply regulator that uses the same connector as the tractor, but without sucess.
I can't buy I2C extender at the moment so if this doesn't works I will have to try CAN Bus communication and add an Arduino Nano to run the LCD.
Thank you for your time.
Alex
First off all I would to to apologige for such a long writing, but I like to explain every delail on my projects so people can understand why I did the things I did.
I have an Teensy LC that reads 4 sensors and then shows the sensors values in an I2C 20x4 LCD.
The Teensy is powered by 5V in the 5V pin, with the USB line cutted. The LCD is powered by 5V from another power regulator, but grounds are the same.
I had 10K pull-up resistors on the SDA and SCL lines trough 3.3V, everything worked fine on my breadboard.
This is for an agriculture machine and the LCD needs to be apart 6 meters from the Teensy. I only then realised that I2C has distance limitations.
With the 6 meter cable the LCD dind´t work, or random number would appear. I the replaced the 10K pull-up resistor by 1K pull-up resistors, and the systems worked, I even rolled the cable trying to create interferences but the system kept working.
Now is where thing get odd:
I have done all this prototyping with my workbench power supply, an MLINK APS3005S-3D. Once everything was validated, I installed the system in the machine and the 12V power comes from the tractor 12V plug.
For my surprise, the LCD doesn´t show the information, but the Teensy keeps running. For some reason the LCD powered up but it didn´t show information, not even in the previous setup (I suspect that the I2C adapter on the LCD is broken now)
After replacing the LCD I can only get the information if I connect the I2C lines with an 0.1m cable.
Why does it work with the workbench power suply and not with 12V from the tractor? I also tried an laptop power supply regulator that uses the same connector as the tractor, but without sucess.
I can't buy I2C extender at the moment so if this doesn't works I will have to try CAN Bus communication and add an Arduino Nano to run the LCD.
Thank you for your time.
Alex