IC Port

I C is becoming increasingly popular as a means by which to communicate

with sensors. Thus, it made sense to add an I C port to allow users to add

other sensors to their project. One great example would be adding an

external light sensor. Since most weather stations need to be enclosed in a

weatherproof housing, having a light sensor on-board didn’t make much

sense. However, adding the I C port allows one to connect sensors such as

the TSL2561 Luminosity Sensor or the ISL29125 RGB Light Sensor along

with a whole slew of other I C sensors.

I C Pull-ups

Many SparkFun I C Breakouts have solder jumpers for disabling the pull-up

resistors necessary on most I C designs. The Photon Weather Shield is no

different. If you already have a sensor that has pull-ups, you can disable

them on the shield by cutting the traces with a hobby knife. Or, if you would

rather leave the shield as is, you can disable the pull-ups on every I C you

add to the bus. The important thing to remember is that only one device on

the bus needs to have its pull-ups active. All others should be disabled.

Serial 1 Port

There is another port broken out, this time for the USART Serial 1 port on

the Photon. Serial ports are great for debugging. They also allow for various

other wireless technologies to be attached for mesh networking or for user

feedback via an LCD or other display. Let’s say you wanted additional

sensors around you home, well beyond the range of your WiFi signal. You

could attach an Xbee Explorer to the Serial 1 port on the Weather shield

and have your other node (consisting of a stand-alone XBee or an XBee

Arduino combo, for example) out in the field, feeding data back to the

Photon, which then sends the collective data to the web.

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