The team picked out several sensors to enable robot code to respond to the environment. All turned out to have an I2C interface. Fortunately, the RoboRIO has two I2C controllers:

one on the base unit

and one on the MXP expansion connector and broken out by the NavX board.

Since the two rio native i2c connectors have the same pin order, we standardize on that, and adapt all sensors to that pinout. These connectors have 4 pins, in this order, on a 0.1“ header:

• Ground
• +3.3v Power
• SCL
• SDA

0.1” COTS cables like this are helpful for wiring:

http://www.revrobotics.com/rev-31-1537/

We're using two of these. Since they all have the Same I2C address, we can't connect both of them to the i2c host controller without special care. Fortunately, The RoboRIO has two controllers, so we connect one to each.

A short 4-wire cable is built to adapt from the JST connector on the Rev sensor to an 0.1“ female connector. This adaptor cable can plug directly into the RoboRIO for software development. It adapts the pinout to our (Rio) standard, which requires flipping SDA and SCL.

To connect three sensors, one of which requires oddball power, to one I2C port, we built a little breakout adaptor. It has 5 connectors:

• one 4-pin header that is cabled to the RoboRIO
• Two more 4-pin headers for Rev Color and VL53L0X sensors adapted to our standard pinout
• one 5-pin header providing +5v power for a VCNL4010

Ground, SCL, and SDA are simply wired together on all four headers.

+3.3v power connects between the three 4-pin headers.