pymata_iot Usage Notes

Some Examples:

Make sure you have pymata_iot running before running the examples.

• A Simple HTML Example (source code).
• A Full Uno Web Controller (this will bring up a web page). Connect your UNO to your computer, start up pymata_iot as described below, click on the link and you will be controlling your UNO from the browser!

JSON messaging is used to communicate between PyMataIOT and your application.

To see the format for the JSON messages, click on this link, then scroll down to the Method Detail section.

The parameter field describes the message format for a message coming from your application to pymata_iot. The return field describes the format of messages sent from pymata_aio to your application.

These messages are totally asynchronous so your application must be ready to receive them at any time. For example, after setting a pin as an input pin (either analog or digital), pymata_aio will start sending data change messages as soon as they start arriving.

Click here to see the code for a simple html/JavaScript example of setting a pin for PWM mode and then setting its output value to 128.

Using PyMataIOT

PymataIOT is invoked from a command line. Here is the usage information from the command line:

usage: pymata_iot.py [-h] [-host HOSTNAME] [-port PORT] [-wait WAIT]
                     [-comport COM] [-sleep SLEEP] [-log LOG]
                     [-ardIPAddr AIPADDR] [-ardPort AIPPORT]
                     [-handshake HANDSHAKE]

optional arguments:
  -h, --help            show this help message and exit
  -host HOSTNAME        Server name or IP address
  -port PORT            Server port number
  -wait WAIT            Arduino wait time
  -comport COM          Arduino COM port
  -sleep SLEEP          sleep tune in ms.
  -log LOG              redirect console output to log file
  -ardIPAddr AIPADDR    Arduino IP Address (WiFly
  -ardPort AIPPORT      Arduino IP port (WiFly
  -handshake HANDSHAKE  IP Device Handshake String

The default host is "localhost"

The default port is 9000

The default wait is 2 seconds. If you are using a Leonardo, you can set this to zero for quicker boot times.

Here are some typical reset wait times by board type:

Board Type	Seconds
Uno	2 (default)
Leonardo	0
Teensy	5

For other board types, you may need to experiment with this value.

If you wish to override the auto com port detection, then set the comport option.

The -sleep option default is 001 seconds. You probably should not change this value.

The -log option default is False, sending all output to the console.

When pymata_iot successfully starts, you should something like the following on your console:

pymata_aio Version 1.3	Copyright (c) 2015 Alan Yorinks All rights reserved.

Using COM Port:/dev/ttyUSB0

Initializing Arduino - Please wait... Auto-discovery complete. Found 20 Digital Pins and 6 Analog Pins