README
======
This README discusses issues unique to NuttX configurations for the ST
STM32L4R9AI Discovery board from ST Micro. See
https://www.st.com/content/st_com/en/products/evaluation-tools/product-evaluation-tools/mcu-eval-tools/stm32-mcu-eval-tools/stm32-mcu-discovery-kits/32l4r9idiscovery.html
STM32L4R9AI:
Microprocessor: 32-bit ARM Cortex M4 at 120MHz STM32L4R9AI
Memory: 2048 KB Flash and 192+64+384 KB SRAM
ADC: 1x12-bit, 5 MSPS A/D converter: up to 14 external channels
DAC: 2 channels
DFSDM: 4 filters, 8 channels
DMA: 16-stream DMA controllers with FIFOs and burst support
Timers: Up to 11 timers: up to eight 16-bit, two 32-bit timers, two
watchdog timers, and a SysTick timer
GPIO: Up to 131 I/O ports with interrupt capability
I2C: Up to 4 x I2C interfaces
USARTs: Up to 3 USARTs, 2 UARTs, 1 LPUART
SPIs: Up to 3 SPIs
SAIs: Up to 2 dual-channel audio interfaces
CAN interface
SDIO interface
OCTOSPI interface
Camera interface
USB: USB 2.0 full-speed device/host/OTG controller with on-chip PHY
CRC calculation unit
RTC
Board features:
Peripherals: 1 d-pad joystick, 2 x LED, AMOLED display, USC OTG FS,
2 x MEMS Digital Microphones, SAI codec, 16 Mbit PSRAM,
512 Mbit OCTOSPI Flash, current ammeter
Debug: Serial wire debug and JTAG interfaces
Uses a STM32F103 to provide a ST-Link for programming, debug similar to the
OpenOcd FTDI function - USB to JTAG front-end.
Contents
========
- mbed
- Hardware
- Button
- LED
- U[S]ARTs and Serial Consoles
- Segger J-Link
- LQFP64
- Configurations
mbed
====
The STM32L4R9AI-DISCO includes boot loader from mbed:
https://mbed.org/handbook/Homepage
Using the mbed loader:
1. Connect the board to the host PC using the USB connector.
2. A new file system will appear called DIS_L4R9AI; open it with Windows
Explorer (assuming that you are using Windows).
3. Drag and drop nuttx.bin into the MBED window. This will load the
nuttx.bin binary into the board. The DIS_L49RAIO window will
close then re-open and the board will be running the new code.
Hardware
========
Buttons
-------
B1 USER: the user button is connected to the I/O PC13 (pin 2) of the STM32
microcontroller.
LEDs
----
The STM32L4R9AI-DISCO board provides two user LEDs, LD1 (orange) and LD2 (green).
PB0 is LD1 (orange)
PH4 is LD2 (green)
- When the I/O is HIGH value, the LED is on.
- When the I/O is LOW, the LED is off.
These LEDs are 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/stm32_autoleds.c. The LEDs are used to encode OS-related
events as follows when the green LED (PH4) is available:
SYMBOL Meaning LD2
------------------- ----------------------- -----------
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 No change
LED_SIGNAL In a signal handler No change
LED_ASSERTION An assertion failed No change
LED_PANIC The system has crashed Blinking
LED_IDLE MCU is is sleep mode Not used
Thus if LD2 is on, NuttX has successfully booted and is, apparently,
running normally. If LD2 is flashing at approximately 2Hz, then a fatal error
has been detected and the system has halted.
U[S]ARTs and Serial Consoles
----------------------------
USART1
------
Pins and Connectors:
RXD: PA11 CN10 pin 14
PB7 CN7 pin 21
TXD: PA10 CN9 pin 3, CN10 pin 33
PB6 CN5 pin 3, CN10 pin 17
NOTE: You may need to edit the include/board.h to select different USART1
pin selections.
TTL to RS-232 converter connection:
Nucleo CN10 STM32F4x1RE
----------- ------------
Pin 21 PA9 USART1_RX *Warning you make need to reverse RX/TX on
Pin 33 PA10 USART1_TX some RS-232 converters
Pin 20 GND
Pin 8 U5V
To configure USART1 as the console:
CONFIG_STM32L4_USART1=y
CONFIG_USART1_SERIALDRIVER=y
CONFIG_USART1_SERIAL_CONSOLE=y
CONFIG_USART1_RXBUFSIZE=256
CONFIG_USART1_TXBUFSIZE=256
CONFIG_USART1_BAUD=115200
CONFIG_USART1_BITS=8
CONFIG_USART1_PARITY=0
CONFIG_USART1_2STOP=0
USART2
-----
Pins and Connectors:
RXD: PA3 CN9 pin 1 (See SB13, 14, 62, 63). CN10 pin 37
PD6
TXD: PA2 CN9 pin 2(See SB13, 14, 62, 63). CN10 pin 35
PD5
TTL to RS-232 converter connection:
Nucleo CN9 STM32F4x1RE
----------- ------------
Pin 1 PA3 USART2_RX *Warning you make need to reverse RX/TX on
Pin 2 PA2 USART2_TX some RS-232 converters
Solder Bridges. This configuration requires:
- SB62 and SB63 Closed: PA2 and PA3 on STM32 MCU are connected to D1 and D0
(pin 7 and pin 8) on Arduino connector CN9 and ST Morpho connector CN10
as USART signals. Thus SB13 and SB14 should be OFF.
- SB13 and SB14 Open: PA2 and PA3 on STM32F103C8T6 (ST-LINK MCU) are
disconnected to PA3 and PA2 on STM32 MCU.
To configure USART2 as the console:
CONFIG_STM32L4_USART2=y
CONFIG_USART2_SERIALDRIVER=y
CONFIG_USART2_SERIAL_CONSOLE=y
CONFIG_USART2_RXBUFSIZE=256
CONFIG_USART2_TXBUFSIZE=256
CONFIG_USART2_BAUD=115200
CONFIG_USART2_BITS=8
CONFIG_USART2_PARITY=0
CONFIG_USART2_2STOP=0
UART4
------
Pins and Connectors:
RXD: PA1 -> CN11 D5
TXD: PA0 -> CN17 A4
To configure USART4 as the console:
CONFIG_STM32L4_UART4=y
CONFIG_USART4_SERIALDRIVER=y
CONFIG_USART4_SERIAL_CONSOLE=y
CONFIG_USART4_RXBUFSIZE=512
CONFIG_USART4_TXBUFSIZE=256
CONFIG_USART4_BAUD=2000000
CONFIG_USART4_BITS=8
CONFIG_USART4_PARITY=0
CONFIG_USART4_2STOP=0
Virtual COM Port
----------------
Yet another option is to use UART2 and the USB virtual COM port. This
option may be more convenient for long term development, but is painful
to use during board bring-up.
Solder Bridges. This configuration requires:
- SB62 and SB63 Open: PA2 and PA3 on STM32 MCU are disconnected to D1
and D0 (pin 7 and pin 8) on Arduino connector CN9 and ST Morpho
connector CN10.
- SB13 and SB14 Closed: PA2 and PA3 on STM32F103C8T6 (ST-LINK MCU) are
connected to PA3 and PA2 on STM32 MCU to have USART communication
between them. Thus SB61, SB62 and SB63 should be OFF.
Configuring USART2 is the same as given above.
Question: What BAUD should be configure to interface with the Virtual
COM port? 115200 8N1?
Default
-------
As shipped, SB62 and SB63 are open and SB13 and SB14 closed, so the
virtual COM port is enabled.
Segger J-Link
=============
Reference: https://www.segger.com/downloads/application-notes/AN00021
1. Connect J-Link VTref (1) to pin VDD
2. Connect J-Link SWDIO (7) to pin PA13
3. Connect J-Link SWCLK (9) to pin PA14
4. Connect J-Link SWO (13) to pin PB3
5. Connect J-Link RESET (15) to pin NRST
6. Connect J-Link 5V-Supply (19) to pin 5V
7. Connect J-Link GND (4) to pin GND
Jumpers on CN4 (ST-Link) must be removed for external debug.
Configurations
==============
knsh:
----
This is identical to the nsh configuration below except that (1) NuttX
is built as a PROTECTED mode, monolithic module and the user applications
are built separately and, as a consequence, (2) some features that are
only availabled in the FLAT build are disabled.
It is recommends to use a special make command; not just 'make' but make
with the following two arguments:
make pass1 pass2
In the normal case (just 'make'), make will attempt to build both user-
and kernel-mode blobs more or less interleaved. That actual works!
However, for me it is very confusing so I prefer the above make command:
Make the user-space binaries first (pass1), then make the kernel-space
binaries (pass2)
NOTES:
1. At the end of the build, there will be several files in the top-level
NuttX build directory:
PASS1:
nuttx_user.elf - The pass1 user-space ELF file
nuttx_user.hex - The pass1 Intel HEX format file (selected in defconfig)
User.map - Symbols in the user-space ELF file
PASS2:
nuttx - The pass2 kernel-space ELF file
nuttx.hex - The pass2 Intel HEX file (selected in defconfig)
System.map - Symbols in the kernel-space ELF file
The J-Link programmer will except files in .hex, .mot, .srec, and .bin
formats.
2. Combining .hex files. If you plan to use the .hex files with your
debugger or FLASH utility, then you may need to combine the two hex
files into a single .hex file. Here is how you can do that.
a. The 'tail' of the nuttx.hex file should look something like this
(with my comments added):
$ tail nuttx.hex
# 00, data records
...
:10 9DC0 00 01000000000800006400020100001F0004
:10 9DD0 00 3B005A0078009700B500D400F300110151
:08 9DE0 00 30014E016D0100008D
# 05, Start Linear Address Record
:04 0000 05 0800 0419 D2
# 01, End Of File record
:00 0000 01 FF
Use an editor such as vi to remove the 05 and 01 records.
b. The 'head' of the nuttx_user.hex file should look something like
this (again with my comments added):
$ head nuttx_user.hex
# 04, Extended Linear Address Record
:02 0000 04 0801 F1
# 00, data records
:10 8000 00 BD89 01084C800108C8110208D01102087E
:10 8010 00 0010 00201C1000201C1000203C16002026
:10 8020 00 4D80 01085D80010869800108ED83010829
...
Nothing needs to be done here. The nuttx_user.hex file should
be fine.
c. Combine the edited nuttx.hex and un-edited nuttx_user.hex
file to produce a single combined hex file:
$ cat nuttx.hex nuttx_user.hex >combined.hex
Then use the combined.hex file with the to write the FLASH image.
If you do this a lot, you will probably want to invest a little time
to develop a tool to automate these steps.
nsh:
---
Configures the NuttShell (nsh) located at apps/examples/nsh for the
STM32L4R9AI-DISCO board. The Configuration enables the serial interfaces
on UART4. Support for builtin applications is enabled, but in the base
configuration no builtin applications are selected (see NOTES below).
NOTES:
1. This configuration uses the mconf-based configuration tool. To
change this configuration using that tool, you should:
Execute 'make menuconfig' in nuttx/ in order to start the
reconfiguration process.
2. By default, this configuration uses the Generic ARM EABI toolchain
for Linux. That can easily be reconfigured, of course.
CONFIG_HOST_LINUX=y : Builds under Linux
CONFIG_ARMV7M_TOOLCHAIN_GNU_EABIL=y : Generic EABI toolchain for Linux
3. The default console is UART4
4. This example can be used to verify the OTGFS functionality. USB is
not enabled in the default configuration but can be enabled with the
following settings: (TODO: need to test!)
CONFIG_STM32L4_OTGFS=y
CONFIG_USBDEV=y
CONFIG_USBDEV_SELFPOWERED=y
These will enable the USB CDC/ACM serial device
CONFIG_CDCACM=y
CONFIG_CDCACM_EP0MAXPACKET=64
CONFIG_CDCACM_EPINTIN=1
CONFIG_CDCACM_EPINTIN_FSSIZE=64
CONFIG_CDCACM_EPINTIN_HSSIZE=64
CONFIG_CDCACM_EPBULKOUT=3
CONFIG_CDCACM_EPBULKOUT_FSSIZE=64
CONFIG_CDCACM_EPBULKOUT_HSSIZE=512
CONFIG_CDCACM_EPBULKIN=2
CONFIG_CDCACM_EPBULKIN_FSSIZE=64
CONFIG_CDCACM_EPBULKIN_HSSIZE=512
CONFIG_CDCACM_NRDREQS=4
CONFIG_CDCACM_NWRREQS=4
CONFIG_CDCACM_BULKIN_REQLEN=96
CONFIG_CDCACM_RXBUFSIZE=257
CONFIG_CDCACM_TXBUFSIZE=193
CONFIG_CDCACM_VENDORID=0x0525
CONFIG_CDCACM_PRODUCTID=0xa4a7
CONFIG_CDCACM_VENDORSTR="NuttX"
CONFIG_CDCACM_PRODUCTSTR="CDC/ACM Serial"
CONFIG_SERIAL_REMOVABLE=y
These will enable the USB serial example at apps/examples/usbserial
CONFIG_BOARDCTL_USBDEVCTRL=y
CONFIG_EXAMPLES_USBSERIAL=y
CONFIG_EXAMPLES_USBSERIAL_BUFSIZE=512
CONFIG_EXAMPLES_USBSERIAL_TRACEINIT=y
CONFIG_EXAMPLES_USBSERIAL_TRACECLASS=y
CONFIG_EXAMPLES_USBSERIAL_TRACETRANSFERS=y
CONFIG_EXAMPLES_USBSERIAL_TRACECONTROLLER=y
CONFIG_EXAMPLES_USBSERIAL_TRACEINTERRUPTS=y
Optional USB debug features:
CONFIG_DEBUG_FEATURES=y
CONFIG_DEBUG_USB=y
CONFIG_ARCH_USBDUMP=y
CONFIG_USBDEV_TRACE=y
CONFIG_USBDEV_TRACE_NRECORDS=128
CONFIG_USBDEV_TRACE_STRINGS=y
CONFIG_USBDEV_TRACE_INITIALIDSET=y
CONFIG_NSH_USBDEV_TRACE=y
CONFIG_NSH_USBDEV_TRACEINIT=y
CONFIG_NSH_USBDEV_TRACECLASS=y
CONFIG_NSH_USBDEV_TRACETRANSFERS=y
CONFIG_NSH_USBDEV_TRACECONTROLLER=y
CONFIG_NSH_USBDEV_TRACEINTERRUPTS=y
nxhello:
-------
A simple NSH example using apps/examples/nxhello, a very simply test of
basic NX functionality.
