webinar

Webinar goals

We will introduce OpenMRN through the real example of building an IO board. Participants will have to bring their own hardware, and we will write the entire fimware based on the OpenMRN library for turning it into a fully functional IO node. We'll explain the basic concepts on the way.

Features

The IO board we'll be building has the following features:

• CAN bus connection via physical CAN bus, or gridconnect format via serial port or USB-serial connection
• Full OpenLCB-compatible CAN messaging stack, including PIP (Protocol Inquiry Protocol).
• SNIP (Simple Node Info Protocol)
• Datagram protocol
• Memory Configuration Protocol
• ACDI (Abbreviated Configuration Definition Information)
• CDI download
• Automated CDI xml file generation at build time
• Configuration store (simulated EEPROM), Configuration memory space
• Consumers and Producers with debouncing.

We will perform extensive testing using JMRI to drive and configure the node, but eventually we will be connecting different nodes to each other and see the bus operate without JMRI.

Requirements

Target hardware

To attend effectively, you must be in possession of a board from the Development Hardware list. It is possible to build a virtual IO board that runs as a program on your computer, but it's more interesting to work with real hardware.

Connection/interface

There are two options to connect the hardware to your computer: either via CAN-bus and a CAN-USB interface card, or via an USB-Serial port using GridConnect protocol.

• Serial port
  • the TIva launchpads and the mbed LPC1768 have built-in USB-serial connections. You can use these connections to send packets to/from your computer as if there was a CAN-USB adapter and a real CAN bus.
  • The remaining development boards have UART serial ports.
    • You need a USB-Serial (uart, not rs232!) converter to connect this to your computer. These are available for $3 - $20 at various websites. Ensure that you get a 3V device, as all of our example boards use that voltage.
    • Or you can use one of the supported boards with both USB and Serial port (Tiva, mbed) as a USB-Serial converter.
• CAN-bus
  • Connecting your board:
    • you may have a CAN transceiver daughter board for your device
    • you can wire up a CAN transceiver chip on a breadboard (if you have a transceiver chip)
    • or you can wire together two or more boards with a single diode in place of the CAN transceiver
  • Connecting to your computer:
    • you may have an existing CAN-USB interface (e.g. from TCH technologies). This requires your dev board to be equipped with a transceiver.
    • you may be using a second dev board with a supported USB connection (e.g. Tiva, mbed) as a CAN-USB interface. This works both with the transceiver as well as the diode-based solution.

Emulator & Debugger

All of the development hardware comes with built-in emulator that allows you to update the firmware through a USB connection. If you are trying to use dramatically different hardware, you must ensure that you have the necessary JTAG device and connection for it. (But don't try to use dramatically different hardware with less than two weeks' notice for us as the driver, the lowlevel hardware setup and pinout configuration will not be in place and you'll face difficulties.)

Host system

At this point we can operate our build system on Mac and Linux computers. We will most likely not be ready with supporting windows as the host platform for the webinar. You may use a direct installation or a virtual machine. You should probably be familiar with command-line terminal on your host machine.

Pre-work

As a preparation for the webinar, we ask you to test your development host and hardware by

• compiling an existing OpenMRN program (a simple blinking application -- equivalent to "Hello, world" in the embedded world)
• flashing the binary to the target
• and watching it blink

If you intend to use CAN-bus we may also want to test your CAN-transceivers and wiring by a different example.

The goal of this pre-work is to ensure smooth progression during the seminar and not hold up the entire talk with debugging an individual participant's basic connectivity issues.

During the webinar

The webinar will be conducted with Google Hangouts. You should have a gmail or Google+ account to participate actively. We will attempt to record it and then you can watch it on YouTube later -- however, this attempt may fail.

Ensure that you have a headphone or headset available. In the unlikely case that your microphone picks up feedback from your speakers, we will be forced to mute your mic.