Embedded Linux – A Standardized Hardware

Smart Devices. Smart Buildings.

Smart Business. 2013

Embedded Linux – A Standardized Pla<orm for IP ApplicaAons Hardware George Thomas President



What is Embedded Linux?

Embedded Linux is the use of Linux in embedded computer systems such as mobile phones, personal digital assistants, media players, set-‐top boxes, and other consumer electronic devices, networking equipment, machine control, industrial automa=on, naviga=on equipment and medical instruments.

-‐ Wikipedia

However, they leA out Building Automa.on!



What is an IP ApplicaAon?

An IP ApplicaAon is any applicaAon that requires the use of the Internet Protocol (IP)

Users are expec.ng Internet connec.vity and a web-‐based interface. Who does not see this trend? To be successful in the market suppliers need to provide a sophis.cated product in a .mely manner. They need a TCP/IP stack and a web server now. Who wants to develop that? Embedded Linux is the answer.



Linux Advantages and Disadvantages Advantages

•  Cost – no licensing fees •  Open Source – extensive

community support •  Networking – built-‐in TCP/IP

stack •  Performance – mul=tasking

opera=ng system •  Portable – runs on many CPUs

Disadvantages

•  Boot-‐up =me – can be lengthy •  Learning curve – takes =me

and effort to learn

What is important is that there is a community and resources readily

available to assist you in developing a Linux-‐based product



Wired and Wireless IP Router Example

•  4 LAN and one WAN port •  USB wireless LAN port •  Stateful firewall •  Port forwarding •  DHCP client/server •  NAT and PAT rou=ng

Without Linux, this would be a huge design effort



If You Need More Speed Go Get It

If your applicaAon needs more performance, ARM9 processors capable of

operaAon at 1.2 GHz and up are readily available that support the newer faster memories. Linux will run

on several different processors.



5-‐Port GigE Managed Ethernet Switch

•  1 GHz processor •  IEEE 1588 switch controller •  Web server interface •  Linux OS

With Linux, this switch design can be converted into a high-‐speed 4-‐1 IP router.



How Do We Know it Will Work?

•  Get an evalua=on board from the CPU chip supplier and try it out

•  Most CPU suppliers provide a Linux board support package



Concerned About I/O Response Time?

•  Use a low-‐cost CPU for I/O handling with a Linux host

•  Linux processors might not have high resolu=on analog I/O but other micros do



Concerned About Size?

•  A Linux engine can fit into a very small space

•  However, you need to accommodate external RAM and Flash memory



What is common with these 2 apps?

BACnet MS/TP to BACnet/IP Router Modbus RTU to BACnet/IP Gateway

They both use idenAcal Linux pla<orms 166 MHz CPU 16 MB Flash 32 MB RAM



A Single Pla<orm Speeds Development •  IP projects are similar – Need a CPU, memory –  I/O or serial port(s) – Ethernet port

•  The same pla^orm can be – a gateway, router or – a head-‐end



With Linux You Can Add OpAons

•  USB port allows for wireless adapters – Wi-‐Fi – Cellular

•  Just need to find a Linux driver for the USB s=ck



Start with an EvaluaAon Board

•  The CPU supplier provides a reference design, evalua=on board and Linux board support package

•  This allows hardware/soAware development to begin immediately



From SchemaAc Capture to Layout •  With a reference design comes a schema=c, parts list, PCB layout and design guidance

•  Enough informa=on to clone the evalua=on board

•  Shows how they did it but you can customize



Layout to Machine Programming

•  AAer layout comes a bill-‐of-‐material and X-‐Y data to program the SMT machine and Gerber files for PCB fabrica=on

•  A CAM program is used to program the placement machine



Boards are Built on a SMT Line •  The SMT line consists of a paste printer, placement machine and reflow oven connected by conveyors

•  Fine-‐pitch placement, including BGAs, important

•  Component parts are loaded into feeders and trays



Sobware Development Environment

•  Open source Eclipse IDE allows for C/C++ and Java programming

•  Cross compiler for target CPU •  Remote debugging over Ethernet using gdbserver which comes with Linux



Java Applet Development •  Java Applet development is achieved with the same Eclipse IDE

•  Java applets provide for dynamic web pages

•  Debugging can be on the target product or on the evalua=on board



Our Ten Years of Experience with Linux

•  It works – it is stable – and it is improving •  A single hardware pla^orm is possible •  A large community that is willing to help •  A plethora of open source projects provide addi=onal features including IP security



Thank You!

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Embedded Linux – A Standardized Hardware