README
======
This README file provides information about the port of NuttX to the Teensy 4.x board. This board features the
MIMXRT1062DVL6A MCU. Some of the features of this board include:
o Processor
- MIMXRT1062DVL6A processor
o Memory
- 1 Mb RAM memory
- 2 Mb QSPI Flash
- 1 SDIO (4 bit) native SD
o Connectivity
- Micro USB host
- CAN transceivers
- 41 digital pins
- 14 analog pins, 2 ADCs on chip
Contents
========
o LEDs
o Configurations
- Configuration sub-directories
LEDs and buttons
================
LEDs
----
There are two LED status indicators located on the Teensy-4.x board.
The functions of these LEDs include:
- RED LED (loading status)
- dim: ready
- bright: writing
- blink: no USB
- USER LED (D3)
Only a single LED, D3, is under software control.
This LED is not used by the board port unless CONFIG_ARCH_LEDS is
defined. In that case, the usage by the board port is defined in
include/board.h and src/imxrt_autoleds.c. The LED is used to encode
OS-related events as follows:
------------------- ----------------------- ------
SYMBOL Meaning LED
------------------- ----------------------- ------
LED_STARTED NuttX has been started OFF
LED_HEAPALLOCATE Heap has been allocated OFF
LED_IRQSENABLED Interrupts enabled OFF
LED_STACKCREATED Idle stack created ON
LED_INIRQ In an interrupt N/C
LED_SIGNAL In a signal handler N/C
LED_ASSERTION An assertion failed N/C
LED_PANIC The system has crashed FLASH
Thus if the LED is statically on, NuttX has successfully booted and is,
apparently, running normally. If the LED is flashing at approximately
2Hz, then a fatal error has been detected and the system has halted.
Configurations
==============
Information Common to All Configurations
----------------------------------------
Each Teensy-4.x configuration is maintained in a sub-directory and
can be selected as follow:
tools/configure.sh [OPTIONS] teensy-4.x:<subdir>
Where typical options are -l to configure to build on Linux or -c to
configure for Cygwin under Linux. 'tools/configure.sh -h' will show
you all of the options.
Before building, make sure the PATH environment variable include the
correct path to the directory than holds your toolchain binaries.
And then build NuttX by simply typing the following. At the conclusion of
the make, the nuttx binary will reside in an ELF file called, simply, nuttx.
make
The <subdir> that is provided above as an argument to the tools/configure.sh
must be is one of the following.
NOTES:
1. These configurations use the mconf-based configuration tool. To
change any of these configurations using that tool, you should:
a. Build and install the kconfig-mconf tool. See nuttx/README.txt
see additional README.txt files in the NuttX tools repository.
b. Execute 'make menuconfig' in nuttx/ in order to start the
reconfiguration process.
2. All of these configurations are set up to build under Windows using the
"GNU Tools for ARM Embedded Processors" that is maintained by ARM
(unless stated otherwise in the description of the configuration).
https://developer.arm.com/open-source/gnu-toolchain/gnu-rm
That toolchain selection can easily be reconfigured using
'make menuconfig'. Here are the relevant current settings:
Build Setup:
CONFIG_HOST_WINDOWS=y : Window environment
CONFIG_WINDOWS_CYGWIN=y : Cywin under Windows
System Type -> Toolchain:
CONFIG_ARMV7M_TOOLCHAIN_GNU_EABIW=y : GNU ARM EABI toolchain
Configuration sub-directories
-----------------------------
nsh-4.0:
Configures the NuttShell (nsh) located at examples/nsh for Teensy 4.0.
This NSH configuration is focused on low level, command-line driver testing.
Built-in applications are supported, but none are enabled. NutShells then
runs on USB console.
nsh-4.1:
Configures the NuttShell (nsh) located at examples/nsh for Teensy 4.1.
This NSH configuration is focused on low level, command-line driver testing.
Built-in applications are supported, but none are enabled. NutShells then
runs USB console.
can-4.1:
This is an nsh configuration (see above) for Teensy-4.x with added support of
CAN driver. All FlexCANs (CAN1, CAN2, CAN3) are chosen as default. FlexCAN3
is FD capable. Please note that device driver name if counted from zero.
That means for CAN1 -> can0, CAN2 -> can1 and CAN3 -> can2
Bitrate and sample point can be also changed at System type peripheral selection,
basic values are 1 MHz for bitrate and 0.80 for sample point. The FlexCAN driver
for imxrt runs at 80 MHz clock frequency.
The configuration also includes CAN utilities as candump and cansend.
This configuration can be easily changed to work with Teensy 4.0 by
selecting CONFIG_TEENSY_40=y.
This configuration runs over LPUART1 (pins 24 and 25 on Teensy). Communication
over USB console can be turn on, but it couses problems with FlexCAN.
netnsh-4.1:
This configuration is similar to the nsh configuration except that is
has networking enabled, both IPv4 and IPv6. This NSH configuration is
focused on network-related testing.
This configuration cannot be changed to Teensy 4.0 as this board does
not have Ethernet capability.
sd-4.1
This is an nsh configuration (see above) for Teensy-4.x with added support of
connecting micro SD card.
You can mount micro SD card by "mount -t vfat /dev/mmcsd0 /mnt"
This configuration cannot be changed to Teensy 4.0 as this board does
not have micro SD card slot.
lcd-4.1
This is an nsh configuration (see above) for Teensy-4.x with added support of
connecting LCD TFT display with ST7789 controller. You can run framebuffer demo
by starting "fb" in console. The LCD display is connected via SPI4.
This configuration can be easily changed to work with Teensy 4.0 by
selecting CONFIG_TEENSY_40=y.
