NXP’s app note on calculating inductor sizes using MC13783 PWM controller as example. Link here (PDF)
The purpose of this application note is to provide a method of choosing the size of the inductors for the optimized switching regulators versus the current consumption of the application. This will allow to optimize the size and the cost of these components.
New NXP MCUXpresso Eclipse IDE v11:
The V11 of the MCUXpresso IDE is again a big step forward: new Eclipse version and 64bit, updated ARM toolchain, extended debugging support for P&E and Segger in addition to the LinkServer connection. The Global Variables view now supports live variables and graphing for P&E and SEGGER in addition to the LinkServer connection. The new views with the Build Analysis, Image Info, Stack usage and Call Analysis are very useful. And for bare metal applications it includes a heap and stack usage view too.
More details on MCU on Eclipse.
Erich Styger has written an article on how to boot 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.
Booting from a SD card is kind of cool: load a new software to the card, insert it and boot from it. In some applications this can be very useful: in my configuration the processor starts the ROM bootloader, then loads the image from the SD card into RAM and then runs it. In that configuration no internal or external FLASH memory would be needed.
Via MCU on Eclipse.
Erich Styger writes:
Working with low power modes can be challenging. It can severely affect debugging capabilities of a microprocessor or microcontroller. I ported a FreeRTOS application using the Tickless Idle Mode to the NXP i.MX RT1064 board, and all of a sudden, the board was unresponsive to any debugger connection. Luckily the board was not really bricked, but it took me while to find a way to recover it. So for when you end up in a situation with a ‘bricked’ i.MX RT1064 board, this article might be helpful for you to recover it.
More details on MCU on Eclipse blog.
Motor control on LPC84x MCU app note from NXP. Link here (PDF)
This application note describes an implementation of brushless DC motor control with hall effect sensors using the SCTimer/PWM on LPC84x.
Application note from NXP on blood pressure monitor fundamentals using their medical oriented MCUs. Link here (PDF)
Arterial pressure is defined as the hydrostatic pressure exerted by the blood over the arteries as a result of the heart left ventricle contraction. Systolic arterial pressure is the higher blood pressure reached by the arteries during systole (ventricular contraction), and diastolic arterial pressure is the lowest blood pressure reached during diastole (ventricular relaxation). In a healthy young adult at rest, systolic arterial pressure is around 110 mmHg and diastolic arterial pressure is around 70 mmHg.
Erich Styger from MCU on Eclipse writes, “In this article I show the basic steps to get MQTT running on the NXP FRDM-K64F board using MCUXpresso IDE, lwip and MQTT. lwip ois a small and open source TCP/IP stack which is widely used. To keep things very simple in this first post, I’m using it in bare-metal (no RTOS) mode with no encryption/security. The principle applies to any IDE/toolchain, as long there is a lwip port available for your board and IDE/toolchain. I’m using the MCUXpresso IDE as it nicely integrates with the MCUXpresso SDK which includes a lwip port for the FRDM-K64F.”
More details at MCU on Eclipse homepage.
Tough design and software reference from NXP of touch interface. Link here (PDF)
The touch-sensing method is used to replace most of traditional tact switch inputs as a new type of human-machine interface used in home-appliance applications. However, using such kind of detection method in harsh environment is still a challenge for most of product designers. A good balance of fast response and no false trigger in key detection is always an essential factor for the user-interface design. The touch-sensing input (TSI) module in Freescale MCUs provides capacitive touch detection with high sensitivity and durability, which can help customers to adapt this kind of human touch-sensing technology quicker.
This application note describes how to use the S08PT family MCU features in applications with emphasis on both touch-sensing interface and safety aspect. Different techniques in circuit design, intelligent software control and reliable mechanical structure are illustrated in this application note to show how to achieve a product design with protection features for handling faults and fast TSI response without any false trigger in extreme conditions. Most of the critical scenarios and unexpected use cases from the end-user point of view must be fully studied and well-covered in advance to prevent any serious flaw persisting in the final design stage which causes significant delay in the whole project schedule.
A reference design from NXP about water level detection using pressure sensor. Link here (PDF)
Many washing machines currently in production use a mechanical sensor for water level detection. Mechanical sensors work with discrete trip points enabling water level detection only at those points. The purpose for this reference design is to allow the user to evaluate a pressure sensor for not only water level sensing to replace a mechanical switch, but also for water flow measurement, leak detection, and other solutions for smart appliances. This system continuously monitors water level and water flow using the temperature compensated MPXM2010GS pressure sensor in the low cost MPAK package, a dual op-amp, and the MC68HC908QT4, eight-pin microcontroller.
UHF label antenna design guide from NXP, app note here (PDF!)
This document provides a general overview on basics of UHF wave propagation, as well as practical considerations of UHF label antenna design. The target is to guide the reader to a good understanding of UHF label antenna design in theory and in practice.