Connecting a TSL2561 luminosity sensor


I am looking to connect a TSL2561 digital luminosity sensor (Adafruit ID 439) to an XBee Pro Series 2 as part of a remote garden sensor array at my school (outdoor classroom). The array will have analog temperature (10K thermistor from Adafruit ID 372) and moisture (DFRobot RB-Dfr-161) sensors as well, and all three sensors will be read by the XBee directly, which will then transfer the voltage readings wirelessly to another Xbee connected to an Arduino housed inside the school.

Anyway, my research tells me I need to use a Pro as the standard XBee lacks an i2c connection. The issue I’m concerned with is that this particular sensor requires 2 i2c connections (typically connected directly to Arduino). Does the Pro have 2 pins that can handle i2c directly? I came across some info that pins 7 and 19 are i2c, but I haven’t been able to confirm this with the Digi documentation I’ve searched through thus far.

My goal is to make inexpensive and low power sensor arrays in the garden beds that can read the soil temp, soil moisture and light intensity the plants are growing with. So I want to use XBees to directly connect the sensors to. If I have to put an Arduino in each bed, plus the Xbee, that’s going to double the cost per array and make this not feasible.

Any guidance you all could provide would be greatly appreciated!


I’ve not heard of any I2C capability with the Xbee modules:
You might want to contact tech support.


According to this post here, it’s been done:,8759

The documentation I’ve read here:

lists i2c as an interface on the programmable Pro model.

It just doesn’t specify which pins and how many would be i2c.