FreeRTOS and LPC Microcontrollers. Richard Barry Design West, San Jose, 2013

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1 FreeRTOS and LPC Microcontrollers Richard Barry Design West, San Jose, 2013

2 Introductions Real Time Engineers Ltd. FreeRTOS FreeRTOS+ WITTENSTEIN high integrity systems OpenRTOS SafeRTOS Richard Barry Director, Real Time Engineers Ltd Founder, the FreeRTOS project Copyright 2013 Real Time Engineers Ltd.

3 Agenda Why would I want an RTOS? What is FreeRTOS? What is FreeRTOS+? The FreeRTOS value proposition Using FreeRTOS FreeRTOS running on LPC LPCOpen, a complete embedded solution from NXP Copyright 2013 Real Time Engineers Ltd. 3 April 25, 2013

7 Scaling and Maintenance Integration of COTS components Code re-use Mixed processing requirements Concurrent team development Testability Mix of hard and soft real time Scalable (not susceptible to application change) Tolerant of hardware change Copyright 2013 Real Time Engineers Ltd. 7

8 Scaling and Maintenance Integration of COTS components Code re-use Mixed processing requirements Concurrent team development Interdependency between timing and functionality Testability Mix of hard and soft real time Scalable (not susceptible to application change) Tolerant of hardware change Copyright 2013 Real Time Engineers Ltd. 8

The RTOS Alternative Task #1 Task #2 Task #3 Delay (wait) until it is time to start the next control cycle Wait for interrupt Wait for a message from another task

9 The RTOS Alternative Task #1 Task #2 Task #3 Delay (wait) until it is time to start the next control cycle Wait for interrupt Wait for a message from another task Perform control function Process data Process message Output results Task #4 Send a message to another task Background processing Copyright 2013 Real Time Engineers Ltd. 9

10 The RTOS Alternative Task #1 Task #2 Task #3 Delay (wait) until it is time to start the next control cycle Wait for interrupt Wait for a message from another task Perform control function Output results Process data Process message Autonomous sequential tasks, RTOS takes care of signaling, communication and timing Task #4 Send a message to another task Background processing Copyright 2013 Real Time Engineers Ltd. 10

11 Scaling and Maintenance Integration of COTS components Code re-use Mixed processing requirements Concurrent team development Testability Mix of hard and soft real time Scalable (not susceptible to application change) Tolerant of hardware change Copyright 2013 Real Time Engineers Ltd. 11

12 Scaling and Maintenance Integration of COTS components Code re-use Mixed processing requirements Concurrent team development Decoupled, functionally cohesive code Testability Mix of hard and soft real time Scalable (not susceptible to application change) Tolerant of hardware change Copyright 2013 Real Time Engineers Ltd. 12

13 Agenda Why would I want an RTOS? What is FreeRTOS? What is FreeRTOS+? The FreeRTOS value proposition Using FreeRTOS FreeRTOS running on LPC LPCOpen, a complete embedded solution from NXP Copyright 2013 Real Time Engineers Ltd. 13 April 25, 2013

16 The RT In RTOS Deterministic Hard real time it absolutely must Soft real time it should T2 preempts T3 T1 preempts T2 Task1 (high, event) Task2 (med, periodic) Task3 (low, event) Idle task t1 t2 t3 t4 t5 t6 t7 t8 t9 t11 t10 t12 t13 Copyright 2013 Real Time Engineers Ltd. 16

18 Moderated Open Source Real Time Kernel is everywhere... Professionally developed, quality controlled, robust and supported Downloaded more than 103,000 times in 2012 Polled top in class for the questions which kernel are you currently using? and which kernel are you most likely to use in your next project in the 2011, 2012 and 2013 EETimes Embedded Market Surveys Copyright 2013 Real Time Engineers Ltd. 18

without ever contacting us, but with the complete peace of mind that they could opt to switch to a fully

19 FreeRTOS Value Proposition FreeRTOS offers lower project risks and a lower total cost of ownership than commercial alternatives because: It is fully supported and documented Most people take products to market without ever contacting us, but with the complete peace of mind that they could opt to switch to a fully indemnified commercial license (with dedicated supports) at any time. Copyright 2013 Real Time Engineers Ltd. 19

20 Is It Free, Even For Commercial Use? Yes Moderated open source Proprietary code remains proprietary FreeRTOS API Application Source Driver Source FreeRTOS Source Middleware Source Closed Source Open Source Copyright 2013 Real Time Engineers Ltd. 20

21 Under Constant Development Latest features include Tick suppression for low power applications Queue sets Port optimised task selection Without Tick Suppression Interrupt Scheduler Task Idle Task Copyright 2013 Real Time Engineers Ltd. 21

22 Under Constant Development Latest features include Tick suppression for low power applications Queue sets Port optimised task selection With Tick Suppression Interrupt Scheduler Task Idle Task Copyright 2013 Real Time Engineers Ltd. 22

23 FreeRTOS+ Ecosystem FreeRTOS+ TCP/IP Pre-built libraries for easy integration of TCP/IP and related protocols into cost-sensitive applications IO Add an open(), read(), write(), ioctl() peripheral interface to your application Safety & Certification A pre-certified kernel for microcontrollers, with a similar usage model to FreeRTOS Nabto Exciting new technology that redefines the web device RTOS Training Expert instructor led RTOS training to maximise productivity delivered online or on site UDP/IP Thread aware, Berkeley sockets based, efficient UDP/IP stack CLI Enable your application to efficiently process command line input Trace Get 15 graphically interlinked views of the trace, providing an unprecedented level of insight SSL and TLS State of the art networking security for embedded systems Your Product Here? Copyright 2013 Real Time Engineers Ltd. 23

25 Agenda Why would I want an RTOS? What is FreeRTOS? What is FreeRTOS+? The FreeRTOS value proposition Using FreeRTOS FreeRTOS running on LPC LPCOpen, a complete embedded solution from NXP Copyright 2013 Real Time Engineers Ltd. 25

29 Task Example #1 /* Tasks always have the same prototype. */ void vprocessmessages( void *pvparameters ) { for( ;; ) { xqueuereceive( xqueue, &xmessage, portmax_delay ); ProcessMessage( &xmessage ); } } /* A task cannot exit without first deleting itself. */ vtaskdelete( NULL ); Copyright 2013 Real Time Engineers Ltd. 29

30 Task Example #2 /* Tasks always have the same prototype. */ void vprocessmessages( void *pvparameters ) { portticktype xlastwaketime; const portticktype xfrequency = 10; /* Initialise the xlastwaketime variable with the current time. */ xlastwaketime = xtaskgettickcount(); } for( ;; ) { /* Wait for the next cycle. */ vtaskdelayuntil( &xlastwaketime, xfrequency ); vperiodicprocessingdonehere(); } Copyright 2013 Real Time Engineers Ltd. 30

31 Create a Task Start the Scheduler xtaskcreate( /* A pointer to the task function. */ atask, vtaskstartscheduler(); /* Textual name. */ "LED", /* Dimensions of the task stack. */ configminimal_stack_depth, /* Parameters passed into the task. */ (void *) 0, /* The priority of the task. */ 2, /* A handle for the task. */ NULL ); Copyright 2013 Real Time Engineers Ltd. 31

32 Agenda Why would I want an RTOS? What is FreeRTOS? What is FreeRTOS+? The FreeRTOS value proposition Using FreeRTOS FreeRTOS running on LPC LPCOpen, a complete embedded solution from NXP Copyright 2013 Real Time Engineers Ltd. 32

35 LPCOpen from NXP LPCOpen is free software from NXP for use with NXP MCUs Peripheral drivers LPCUSBlib, with support for many classes SWIM (NXP s lightweight graphics library) Examples Includes pre-ported third party open source and licensed software Support and examples for FreeRTOS LwIP network stack emwin (binary graphics library licensed from Segger for NXP customers) ChaN FatFs Cortex-M CMSIS DSP library LPCOpen is available for download on Copyright 2013 Real Time Engineers Ltd.

36 Benefits of LPCOpen Supports all NXP Cortex-M based MCUs Similar APIs across processor families Available for Keil s µvision, IAR s EWARM, LPCXpresso Supports hardware from Embedded Artists, NGX, Keil, Hitex, and more Thoroughly tested, maintained, and documented code Meaningful application examples using multiple peripherals, running stand-alone or under an RTOS Steadily increasing number of example applications, including USB audio, HID, Web Server, etc Copyright 2013 Real Time Engineers Ltd.

37 The LPCOpen platform structure Core Library Board layer Chip layer IP layer LwIP LPCUSBlib emwin SWIM FreeRTOS LPCOpen Platform LPCUSBlib examples LwIP examples Peripheral examples emwin examples OS examples HID, CDC Mass Storage Audio Host : : Webserver TCP/IP echo Internet radio : : Power Save Dual Core CAN SCT SGPIO : Touchscreen Animation : : Dual Core OS Tickless OS : : Copyright 2013 Real Time Engineers Ltd.

FreeRTOS - Common Task Design Patterns in Multi-tasking Applications

FreeRTOS - Common Task Design Patterns in Multi-tasking Applications Richard Barry, Founder Real Time Engineers Ltd. Class ID: 9C11L Renesas Electronics America Inc. 2012 Renesas Electronics America Inc.