We have a Modern Robotics color sensor. When we try to test it we get an error message that it is not detected and to check wiring or configuration. We are using blocks coding. What are we doing wrong.
The MR color sensor should be connected to the REV Hub as described here:
Note the special crossover cable.
Also see the sensor chart here:
Do you have a 2M Distance Sensor on the same Hub?
From the Application Examples of the Color Sensor:
Recall that I2C sensors must have different addresses in order to operate on the same bus. The Color Sensor V3 and 2m Distance Sensor share the same address.
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Do you have a 2M Distance Sensor on the same Hub?
Fortunately each sensor port on the REV Expansion and Control Hubs is on its own I2C bus, and duplicate addresses only matters if you are chaining sensors on the same bus - like we did when we had the Modern Robotics system, or FRC teams with the roboRIO system. On the REV systems it’s extremely rare to see sensors daisy-chained on the same bus (it requires cabling that nobody sells), so the identical addresses should never conflict.
I’m incredibly confident that the issue is likely exactly what @Westside provided, because with the Modern Robotics color sensor there are two big issues that you have to solve when interfacing it with the REV Hub:
- It’s a 5V sensor so you need the 5v-to-3.3v power-level-shifter circuit to step down the voltage and translate the signal data.
- The wires are not in the correct order for a simple adapter converter, you need to swap signals to be compatible which requires either custom wiring or the specific signal-swapping adapter.
Good eye, though. 
-Danny
We have seen this problem when plugging a Color Sensor V3 and a 2M Distance Sensor on different appropriate ports on the same Expansion Hub.
We have seen this problem when plugging a Color Sensor V3 and a 2M Distance Sensor on different appropriate ports on the same Expansion Hub.
In all transparency, this should not be your issue. I won’t discount your experience and say there wasn’t an issue that you faced, but I am 99.9% confident that conflicting addresses was not your actual problem unless you found a way to chain both devices on the same bus/port. It’s possible that one of the devices may have been damaged and pulls too much power or something (and causes the PTC to shut down the I2C ports completely when both are plugged in) or something like that, but different ports are definitely on separate busses and identical addresses is not the problem.
-Danny
I think the message from Westside was what we needed. We didn’t have the connector cable between the sensor cable and the power level converter. We will find out for sure this afternoon at practice.
Thanks to you all.
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