Serial Bridges... Preparing for the Internet of Things (IoT).

Many embedded applications come down to I/O with "lesser" serial bus on one side (sensors via I2C or SPI or something straightforward like Modbus) via an intelligent agent which then interacts with a "greater" serial bus on the other side (like to a stateful serial protocol like BACnet MSTP, Profibus, ARCNET or even Modbus or USB). This is the essence of a serial bridge.

Most embedded developers pick a micro controller they are familiar with and go directly to work building their bridge.

What if one instead envisioned first how such a bridge could communicate via the Internet of Things?
That is to say - What if one envisioned a TCPIP and web interface from the start?
The web interface would be used for
- startup and configuration (minimizing dip switches and other UI hardware)
- ongoing status (minimizing indicators and hardware UI)
- "dip in" protocols to watch data flow - like RESTful interfaces (MTConnect, Sunspec and others), Modbus TCP and various XML schemas, or even simple .CSV data log files.

Basically one minimally needs two serial interfaces and a TCPIP (Ethernet or Wifi) interface.
[Wifi is a tiny bit harder to auto-configure - but not impossible].

The big problem was always price for TCPIP. And this was usually made worse by the fact that the TCPIP part was an after-thought or add-on - which had to be engineered /into/ the bridge. So what about taking a (cheap) TCPIP intrinsic part and using it "incidentally" as a serial bridge?

The Lantronix xPico is an embodiment of such a bridge, and a particularly "right sized" and economical version. Small ARMs and some recent x86 (Vortex86, Intel and VIA) are getting close,
but none have the sharp focus of the xPico... it being a child of a programme for TCPIP to serial bridging, which just recently branched into multiple serial. There are other small TCPIP UI systems with possible multiple serial... like Moxa and Digi. It is just that the price, tools and possibilities seem uniquely congruent with the xPico.

Only issue with xPico is actually humanly getting access to the two serials via the Hirose. The DKs have this... but also a bunch of excess. Ended up making a breakout DIP40 for prototype work... and working to a policy of keeping all useful pins exposed in viae or test points. See previous blog on breakout pins and APIs.
 
http://albertputnam.blogspot.com/2013/12/new-devices-just-give-us-pins-and-apis.html