First Steps with the LPC55S69-EVK (Dual-Core ARM Cortex-M33 with Trustzone)

For the long Easter weekend I have organized a new toy: the NXP LPC55S69-EVK board: a dual ARM Cortex-M33 running at 100 MHz with ARM TrustZone:

LPC55S69 Microcontroller

LPC55S69 Microcontroller

Continue reading

Advertisements

Tutorial: MCUXpresso SDK with Linux, Part 2: Commandline Debugging with GDB

In “Tutorial: MCUXpresso SDK with Linux, Part 1: Installation and Build with Maked” I used cmake and make to build the SDK application. In this part I’m going to use the command line gdb to debug the application on the board.

Cross-Debugging with GDB

Cross-Debugging with GDB

Continue reading

Tutorial: MCUXpresso SDK with Linux, Part 1: Installation and Build with Make

I admit: my work laptop machine is running a Windows 10 OS by default. But this does not prevent me running Linux in a Virtual Machine (VM). Each host platform has its benefits, and I don’t feel biased to one or the other, but I have started using Ubuntu more and more, simply because I have worked more on Embedded Linux projects. While I have used mostly Windows with Eclipse for NXP LPC, Kinetis and i.MX platforms in the past, I started using Ubuntu too from last year with the NXP MCUXpresso SDK. I did not find much documentation about this on the web, so I thought it might be a good idea to write a tutorial about it. So here we go…

Building NXP MCUXpresso SDK on Linux Ubuntu

Continue reading

Be aware: Floating Point Operations on ARM Cortex-M4F

My mantra is *not* to use any floating point data types in embedded applications, or at least to avoid them whenever possible: for most applications they are not necessary and can be replaced by fixed point operations. Not only floating point operations have numerical problems, they can lead to performance problems as in the following (simplified) example:

#define NOF  64
static uint32_t samples[NOF];
static float Fsamples[NOF];
float fZeroCurrent = 8.0;

static void ProcessSamples(void) {
  int i;

  for (i=0; i<NOF; i++) {
    Fsamples[i] = samples[i]*3.3/4096.0 - fZeroCurrent;
  }
}

Continue reading

Remote Debugging with USB based JTAG/SWD Debug Probes

For some projects it is not possible to have the device under debug available on my desk: the board might be in another room, on another site or in a place where physical access is not possible or even dangerous. In that case an IP-based debug probe (see Debugging ARM Cores with IP based Debug Probes and Eclipse) is very useful: as long as I can access its IP address, that works fine. It is an excellent solution even if the board is moving or rotating: hook it up to a WLAN access point and I still can use it as it would be on my desk.

But what if I have a debug probe only connected to USB? This article shows how to turn a USB debug probe into a IP-based debug solution: that way I can easily debug a board from remote, connected to the network:

IP Based Debugging with USB Debug Probe

IP Based Debugging with USB Debug Probe

Continue reading

MCUXpresso IDE V10.3.1 available

On Friday a new release of the Eclipse Oxygen based NXP MCUXpresso IDE V10.3.1 has been made available. The IDE supports MacOS, Linux and Windows 32/64-bit and will be 64-bit only going forward.

MCUXpresso 10.3.1 About Information

MCUXpresso 10.3.1 About Information

Continue reading

Tutorial: Blinky with the NXP LPC845-BRK Board

The NXP LPC845-BRK board is a sub-$6 breadboard friendly development board with an ARM Cortex-M0+ on it. This tutorial is about developing a ‘blinky’ on it using MCUXpresso.

Binky on NXP LPC845-BRK Board

Binky on NXP LPC845-BRK Board

Continue reading

Tutorial: Transforming the NXP LPC845-BRK into a CMSIS-DAP Debug Probe

The NXP LPC845-BRK board is a tiny an inexpensive (sub $6) breakout board. The board includes a CMSIS-DAP (LPC11U35) on-board debug probe which can be used as a debug probe to debug any NXP LPC, Kinetis or i.MX RT device 🙂

LPC845-BRK used to debug robot

LPC845-BRK used to debug a Sumo Battle Robot

Continue reading

Unboxing the NXP LPC845-BRK Board

I really love tiny and bread board friendly boards, especially if they are very affordable and can be use with Eclipse based tools. So I was excited to see the NXP LPC845-BRK board to be available at Mouser, so I ended up ordering multiple boards right away. Why multiple? Because they only cost CHF 5.95 (around $6)!

NXP LPC845-BRK Board

NXP LPC845-BRK Board

Continue reading

Tutorial: HD44780 Display Driver with NXP MCUXpresso SDK

In the age of high-resolution graphical LCDs using a character display might look like a bit anachronistic. But these displays provide a lot of value for me as they are robust, available in different shapes and number of lines. And such a character display can be a better solution for an industrial application.

hd44780 display with NXP FRDM-KW41Z Board

hd44780 display with NXP FRDM-KW41Z Board

Continue reading

Tutorial: Booting the NXP i.MX RT from Micro SD Card

It is a common thing to boot a Linux system (see the Raspberry Pi) from a micro SD card. It is not that common for a microcontroller. The NXP i.MX RT ARM Cortex-M7 fills that gap between these two worlds. No surprise that it features a ROM bootloader which can boot from a micro SD card.

SD Card with i.MX RT1052

SD Card with i.MX RT1052

Continue reading

FreeRTOS: how to End and Restart the Scheduler

Most host or desktop systems (say Linux, Mac or Windows) have a normal use case where you start the operating system say in the morning and shut it down in the evening, and then you leave the machine. Embedded Systems are different: they are not attended, and they are supposed to run ‘forever’. Not every embedded system needs to run an OS (or in that world: Real-Time Operating System or RTOS), but the same applies here: after the RTOS is started, it is not intended that it will shutdown and restart. To the extend that you won’t they support the ‘shutdown’ and ‘restart’ functionality at all. In case of gathering coverage information this would be really useful:

coverage information from freertos application

coverage information from FreeRTOS application

In the case of FreeRTOS: what if I really need to shutdown the RTOS and restart it again, as by default this is not supported. This is what this article is about …

Continue reading

GDB All-Stop and Non-Stop Mode with LinkServer

GDB supports a mode which allows the GDB debug client to read memory while the target is running. This allows features like ‘live variables’: that way I can see the variables refreshed and changing over time without halting the target. Another functionality which comes with that feature is to check stopped threads or to see all threads in the system.

multiple freertos threads in debug view

multiple FreeRTOS threads in debug view

Continue reading

Freelink LPC4322JET100 based Debug Circuit on NXP i.MX RT1064-EVK Board

As noticed in “First Steps with the NXP i.MX RT1064-EVK Board” there is a new LPC4322 based debug interface on the RT1064-EVK board.

LPC4322JET100 based Debug Interface

LPC4322JET100 based Debug Interface

Continue reading

First Steps with the NXP i.MX RT1064-EVK Board

I always reserve time between Christmas and New Year to get my hands on technology pieces which I might not have any time otherwise. Among different things I ordered the NXP i.MX RT1064-EVK board from Mouser.com, and it arrived right before Christmas. Time to have it unboxed and started….

i.MX RT1064 Processor

i.MX RT1064 Processor

Continue reading

Variable Width Character Encoding in Eclipse Editor

Dealing with variable width character encoding as with UTF-8 is pretty much a standard these days, at least in the Desktop programming world. This is not so much true when programming embedded devices and microcontroller. In any case, Eclipse has you covered. This is especially helpful dealing with non-ASCII character codes in comments:

Comment with UTF-8 in Eclipse

Comment with UTF-8 in Eclipse

Continue reading

New NXP MCUXpresso IDE V10.3.0 Release

Friday this week NXP has released a new version of their flagship IDE: the MCUXpresso IDE V10.3.0. The version number indicates an incremental update from the earlier V10.2.1,  but there are many exciting features and new features which make me switch my lecture material to this new IDE for the next semester.

MCUXpresso IDE V10.3.0

MCUXpresso IDE V10.3.0

Continue reading

Playing Zork with FreeRTOS on ARM in three different Ways

You might wonder what ‘Zork‘ is? Zork is one of the first and earlist fictive computer games, written around 1977 and 1979, written in MDL on a DEC PDP-10 by members of the MIT Dynamic Modelling group (see https://en.wikipedia.org/wiki/Zork). I believe the first time I have played Zork was around 1984 on a Commodore 64.

Zork

Zork

Continue reading

Tutorial: Catching Rogue Memory Accesses with Eclipse and GDB Watchpoints

Eclipse is great: it gives me the tools and capabilities to solve the really hard bugs to find. An example of that ‘hard’ category are ‘rogue’ memory accesses: something in the application is accessing an unwanted memory location and corrupts the data. This might be very sporadic, or takes a long while until it happens. With normal ‘stop-mode’ debugging (setting a normal breakpoint) and stepping usually won’t let me find that bug, as it might be coming from a pointer somewhere. Maybe from an interrupt routine. Or maybe an unitialized or corrupted pointer corrupts to my memory. Usually all what I know is the memory adddress of the data, maybe what is written, but not what or who is writing to that location.

In this article I’m using one of the ‘less-known’ debugging techniques available in Eclipse and CDT and how it works: watchpoints!

Watchpoint with Condition

Watchpoint with Condition

In this article I’m using one of the ‘less-known’ debugging techniques available in Eclipse and CDT and how it works: watchpoints!

Continue reading

i.MX RT1050 EVK vs. EVKB

I noticed on Mouser.com that there is a new i.MX RT1050 board: the EVKB one. I have used the EVK (the one without the ‘B’) for several weeks (see “MCUXpresso IDE V10.1.0 with i.MX RT1052 Crossover Processor” and “Adding a Rocktech Capacitive Touch LCD to the NXP i.MX RT1052 EVK“). I needed anyway a second board, so I ordered that EVKB from Mouser, and after some delay and waiting it arrived on my desk. So far this boards seems to be a better one:

i.MX RT1050 EVKB Board

i.MX RT1050 EVKB Board

Continue reading