Serial line oriented protocol for controlling GPIO on Raspberry Pi, Arduino, etc.

Reading, writing and listening to pins on microdevices is a very common activity. It's also surprisingly touchy to do in some languages (Node) or just kinda annoying (such as in Wiring on Arduino) if you're used to major languages.

We abstract out general IO operations, wrap them up in a TTY / serial port oriented protocol, and then it's easily bridged to the language of your choice.

This is the code you're probably most interested in. When you're using the clients it looks like you're directly interacting with GPIO. In fact, you're going through a line-oriented serial protocol that

The fun code that does all the work. The client code knows what to run. You can run these up by hand for fun and type commands

Sample Node code

The inspiration for this is based on this code, which we hope to be compatible with https://sites.google.com/site/robertovalgolio/sistemi-programmi/arduino-serial-protocol

Requests and responses are one per line, and data bits are separated by commas. There is no backslashing or anything allowed or needed.

The requests don't have to be in sync with responses, and you may get many responses back for a single request. Coordination between requests and responses is done through the parameter, which can be mostly anything though we suggest monotonically increasing numbers is the best way to go about this.

We're mosly set up to deal with Integer data but this may be extended to

Requests are in the format

<seq>,<command>,<pin>[,<value>]

For example, set Pin 10 to "on":

909,DigitalWrite,10,1

Read Pin 8

910,DigitalRead,8

Tell me all changes to Pin 9

911,DigitalListen,9

Responses are in the format

<seq>,<result>

If the result is "-", no further results are expected for that sequence number

For the Set 10 on example above:

909,-

For the read Pin 8 example above (it's off).

910,0

For the notification on Pin 9 example above. The first response is just acking that the command was received. The following respones are based on the value changes over time. These do not need to come in all together and may be intersperced with other results and requests

911,
911,1
911,0
911,1
911,0
911,1