Control 3 LED over the NET attached to a SparkCore. The LED are on pin A4, A5 and A6.
Example:
curl https://api.spark.io/v1/devices/0123456789abcdef01234567/led \
-d access_token=1234123412341234123412341234123412341234 \
-d params=1,100
The params are (1-3),(0-255)