========== Teensy-4.x ========== The `Teensy 4.0 `_ and `Teensy 4.1 `_ are development boards from PJRC. Both boards use i.MX RT1060 MCU, feature several I/Os pins and on-board LED. Features ======== - Processor - MIMXRT1062DVL6A processor - Memory - 1 MB RAM memory - 2 MB Flash (Teensy 4.0) - 8 MB Flash (Teensy 4.1) - 1 SDIO (4 bit) native SD - Connectivity - Micro USB host - CAN transceivers - UART, SPI, I2C - PWM output pins - 10/100 Mb Ethernet (Teensy 4.1 only) - Digital audio in/out 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 ============== 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 causes 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: .. code-block:: console $ 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``. Flash ===== Teensy 4.x boards does not have debugger therefore external firmware has to be used to load NuttX. `Teensy Loader `_ can be installed and then NuttX can be loaded by: .. code-block:: console $ teensy_loader_cli --mcu=TEENSY41 -v -w nuttx.hex For Teensy 4.0 board, switch ``--mcu=TEENSY41`` to ``--mcu=TEENSY40``.