Can I expand my number of Outputs without using more GPIO pins?

Yes, there are currently two I/O expansion chips supported by Mycodo, the PCF8574 (8 channels) and MCP23017 (16 channels). Each will allow you to control the high/low state of either 8 or 16 pins, depending on which chip you use. There are many breakout boards created around these chips, with a few even incorporating relays as well. This is a nice solution to expand the number of outputs without sacrificing GPIO pins, as both chips communicate via 2 wires with I2C.

Note until release: The MCP23017 will be available in the next release and is not yet available unless you upgrade to master.