README
======
This README discusses issues unique to NuttX configurations for the
STMicro STM32L-Discovery development board. The STM32L-Discovery board
is based on the STM32L152RBT6 MCU (128KB FLASH and 16KB of SRAM).
The STM32L-Discovery and 32L152CDISCOVERY kits are functionally
equivalent. The difference is the internal Flash memory size (STM32L152RBT6
with 128 Kbytes or STM32L152RCT6 with 256 Kbytes).
Both boards feature:
- An ST-LINK/V2 embedded debug tool interface,
- LCD (24 segments, 4 commons),
- LEDs,
- Pushbuttons,
- A linear touch sensor, and
- four touchkeys.
Contents
========
- GPIO Pin Usage
- Development Environment
- GNU Toolchain Options
- IDEs
- NuttX EABI "buildroot" Toolchain
- NuttX OABI "buildroot" Toolchain
- NXFLAT Toolchain
- LEDs
- Serial Console
- Debugging
- STM32L-Discovery-specific Configuration Options
- Configurations
GPIO Pin Usage
==============
----- --------------------- -------------------------------- ----------------
GPIO ALTERNATE FUNCTION BOARD FUNCTION P1/P2
----- --------------------- -------------------------------- ----------------
PA0 WKUP1/USART2_CTS/ Push button (PA0), WAKE UP (Iuu) P1, pin 15
ADC_IN0/TIM2_CH1_ETR
/COMP1_INP
PA1 USART2_RTS/ADC_IN1/ LCD SEG0 P1, pin 16
TIM2_CH2/LCD_SEG0/
COMP1_INP
PA2 USART2_TX/ADC_IN2/ LCD SEG1 P1, pin 17
TIM2_CH3/TIM9_CH1/
LCD_SEG1/COMP1_INP
PA3 USART2_RX/ADC_IN3/ LCD SEG2 P1, pin 18
TIM2_CH4/TIM9_CH2/
LCD_SEG2/COMP1_INP
PA4 SPI1_NSS/USART2_CK/ Measurement (Iuu) P1, pin 19
ADC_IN4/DAC_OUT1/
COMP1_INP
PA5 SPI1_SCK/ADC_IN5/ --- P1, pin 20
DAC_OUT2/
TIM2_CH1_ETR/COMP1_
INP
PA6 SPI1_MISO/ADC_IN6/ Linear Touch Sensor (PA6) ---
TIM3_CH1/TIM1_BKIN/
LCD_SEG3/TIM10_CH1/
COMP1_INP
PA7 SPI1_MOSI/ADC_IN7/ Linear Touch Sensor (PA7) ---
TIM3_CH2/TIM1_CH1N
/LCD_SEG4/TIM11_CH1/
PA8 USART1_CK/MCO/ LCD glass COM0 P2, pin 23
PA9 USART1_TX/LCD_COM1 LCD glass COM1 P2, pin 22
PA10 USART1_RX/LCD_COM2 LCD glass COM2 P2, pin 21
PA11 USART1_CTS/USBDM/ --- P2, pin 20
SPI1_MISO
PA12 USART1_RTS/USBDP/ --- P2, pin 19
SPI1_MOSI
----- --------------------- -------------------------------- ----------------
PB0 ADC_IN8/TIM3_CH3/ Linear Touch Sensor (PB0) ---
LCD_SEG5/COMP1_INP/
VREF_OUT
PB1 ADC_IN9/TIM3_CH4/ Linear Touch Sensor (PB1) ---
LCD_SEG6/COMP1_INP/
VREF_OUT
PB2/ --- --- P1, pin 21
BOOT1
PB5 I2C1_SMBAl/TIM3_CH2/ LCD SEG5 P2, pin 9
SPI1_MOSI/COMP2_INP/
LCD_SEG9
PB6 I2C1_SCL/TIM4_CH1/ LED Blue P2, pin 8
USART1_TX/LCD_SEG8
PB7 I2C1_SDA/TIM4_CH2/ LED Green P2, pin 7
USART1_RX/PVD_IN
PB8 TIM4_CH3/I2C1_SCL/ LCD SEG13 P2, pin 4
LCD_SEG16/TIM10_CH1
PB9 TIM4_CH4/I2C1_SDA/ LCD glass COM3 P2, pin 3
LCD_COM3/TIM11_CH1
PB10 I2C2_SCL/USART3_TX/ LCD SEG6 P1, pin 22
TIM2_CH3/LCD_SEG10
PB11 I2C2_SDA/USART3_RX/ LCD SEG7 P1, pin 23
TIM2_CH4/LCD_SEG11
PB12 SPI2_NSS/I2C2_SMBA/ LCD SEG8 P1, pin 24
USART3_CK/LCD_SEG1
2/ADC_IN18/COMP1_INP
/ TIM10_CH1
PB13 SPI2_SCK/USART3_CTS/ LCD SEG9 P1, pin 25
LCD_SEG13/ADC_IN19/
COMP1_INP/TIM9_CH1
PB14 SPI2_MISO/USART3_RT LCD SEG10 P1, pin 26
S/LCD_SEG14/ADC_IN20
/ COMP1_INP/TIM9_CH2
PB15 SPI2_MOSI/TIM1_CH3N/ LCD SEG11 P1, pin 27
LCD_SEG15/ADC_IN21/
COMP1_INP/TIM11_CH1/
RTC_50_60Hz
----- --------------------- -------------------------------- ----------------
PC0 ADC_IN10/LCD_SEG18/ LCD SEG14 P1, pin 11
COMP1_INP
PC1 ADC_IN11/LCD_SEG19/ LCD SEG15 P1, pin 12
COMP1_INP
PC2 ADC_IN12/LCD_SEG20/ LCD SEG16 P1, pin 13
COMP1_INP
PC3 ADC_IN13/LCD_SEG21/ LCD SEG17 P1, pin 14
COMP1_INP
PC4 ADC_IN14/LCD_SEG22/ Linear Touch Sensor (PC4) ---
COMP1_INP
PC5 ADC_IN15/LCD_SEG23/ Linear Touch Sensor (PC5) ---
COMP1_INP
PC6 TIM3_CH1/LCD_SEG24 LCD SEG18 P2, pin 27
PC7 TIM3_CH2/LCD_SEG25 LCD SEG19 P2, pin 26
PC8 TIM3_CH3/LCD_SEG26 LCD SEG20 P2, pin 25
PC9 TIM3_CH4/LCD_SEG27 LCD SEG21 P2, pin 24
PC10 USART3_TX/LCD_SEG28 LCD SEG22 P2, pin 15
/LCD_SEG40/LCD_COM4
PC11 USART3_RX/LCD_SEG2 LCD SEG23 P2, pin 14
9/LCD_SEG41/
LCD_COM5
PC12 USART3_CK/LCD_SEG3 --- P2, pin 13
0/LCD_SEG42/
LCD_COM6
PC13 RTC_AF1/WKUP2 2 CNT_ IDD CNT_EN P1, pin 4
EN 4
PC14 OSC32_IN 3 OSC32_IN OSC32_IN P1, pin 5
PC15 OSC32_OUT 4 OSC32_OUT OSC32_OUT P1, pin 6
----- --------------------- -------------------------------- ----------------
PD2 TIM3_ETR/LCD_SEG31/ --- P2, pin 12
LCD_SEG43/LCD_COM7
----- --------------------- -------------------------------- ----------------
Development Environment
=======================
Either Linux or Cygwin on Windows can be used for the development environment.
The source has been built only using the GNU toolchain (see below). Other
toolchains will likely cause problems.
GNU Toolchain Options
=====================
Toolchain Configurations
------------------------
The NuttX make system has been modified to support the following different
toolchain options.
1. The CodeSourcery GNU toolchain,
2. The Atollic Toolchain,
3. The devkitARM GNU toolchain,
4. Raisonance GNU toolchain, or
5. The NuttX buildroot Toolchain (see below).
All testing has been conducted using the CodeSourcery toolchain for Windows. To use
the Atollic, devkitARM, Raisonance GNU, or NuttX buildroot toolchain, you simply need to
add one of the following configuration options to your .config (or defconfig)
file:
CONFIG_STM32_CODESOURCERYW=y : CodeSourcery under Windows
CONFIG_STM32_CODESOURCERYL=y : CodeSourcery under Linux
CONFIG_STM32_ATOLLIC_LITE=y : The free, "Lite" version of Atollic toolchain under Windows
CONFIG_STM32_ATOLLIC_PRO=y : The paid, "Pro" version of Atollic toolchain under Windows
CONFIG_STM32_DEVKITARM=y : devkitARM under Windows
CONFIG_STM32_RAISONANCE=y : Raisonance RIDE7 under Windows
CONFIG_STM32_BUILDROOT=y : NuttX buildroot under Linux or Cygwin (default)
If you change the default toolchain, then you may also have to modify the PATH in
the setenv.h file if your make cannot find the tools.
NOTE: the CodeSourcery (for Windows), Atollic, devkitARM, and Raisonance toolchains are
Windows native toolchains. The CodeSourcey (for Linux) and NuttX buildroot
toolchains are Cygwin and/or Linux native toolchains. There are several limitations
to using a Windows based toolchain in a Cygwin environment. The three biggest are:
1. The Windows toolchain cannot follow Cygwin paths. Path conversions are
performed automatically in the Cygwin makefiles using the 'cygpath' utility
but you might easily find some new path problems. If so, check out 'cygpath -w'
2. Windows toolchains cannot follow Cygwin symbolic links. Many symbolic links
are used in Nuttx (e.g., include/arch). The make system works around these
problems for the Windows tools by copying directories instead of linking them.
But this can also cause some confusion for you: For example, you may edit
a file in a "linked" directory and find that your changes had no effect.
That is because you are building the copy of the file in the "fake" symbolic
directory. If you use a Windows toolchain, you should get in the habit of
making like this:
make clean_context all
An alias in your .bashrc file might make that less painful.
3. Dependencies are not made when using Windows versions of the GCC. This is
because the dependencies are generated using Windows pathes which do not
work with the Cygwin make.
MKDEP = $(TOPDIR)/tools/mknulldeps.sh
The CodeSourcery Toolchain (2009q1)
-----------------------------------
The CodeSourcery toolchain (2009q1) does not work with default optimization
level of -Os (See Make.defs). It will work with -O0, -O1, or -O2, but not with
-Os.
The Atollic "Pro" and "Lite" Toolchain
--------------------------------------
One problem that I had with the Atollic toolchains is that the provide a gcc.exe
and g++.exe in the same bin/ file as their ARM binaries. If the Atollic bin/ path
appears in your PATH variable before /usr/bin, then you will get the wrong gcc
when you try to build host executables. This will cause to strange, uninterpretable
errors build some host binaries in tools/ when you first make.
Also, the Atollic toolchains are the only toolchains that have built-in support for
the FPU in these configurations. If you plan to use the Cortex-M4 FPU, you will
need to use the Atollic toolchain for now. See the FPU section below for more
information.
The Atollic "Lite" Toolchain
----------------------------
The free, "Lite" version of the Atollic toolchain does not support C++ nor
does it support ar, nm, objdump, or objdcopy. If you use the Atollic "Lite"
toolchain, you will have to set:
CONFIG_HAVE_CXX=n
In order to compile successfully. Otherwise, you will get errors like:
"C++ Compiler only available in TrueSTUDIO Professional"
The make may then fail in some of the post link processing because of some of
the other missing tools. The Make.defs file replaces the ar and nm with
the default system x86 tool versions and these seem to work okay. Disable all
of the following to avoid using objcopy:
CONFIG_RRLOAD_BINARY=n
CONFIG_INTELHEX_BINARY=n
CONFIG_MOTOROLA_SREC=n
CONFIG_RAW_BINARY=n
devkitARM
---------
The devkitARM toolchain includes a version of MSYS make. Make sure that the
the paths to Cygwin's /bin and /usr/bin directories appear BEFORE the devkitARM
path or will get the wrong version of make.
IDEs
====
NuttX is built using command-line make. It can be used with an IDE, but some
effort will be required to create the project.
Makefile Build
--------------
Under Eclipse, it is pretty easy to set up an "empty makefile project" and
simply use the NuttX makefile to build the system. That is almost for free
under Linux. Under Windows, you will need to set up the "Cygwin GCC" empty
makefile project in order to work with Windows (Google for "Eclipse Cygwin" -
there is a lot of help on the internet).
Native Build
------------
Here are a few tips before you start that effort:
1) Select the toolchain that you will be using in your .config file
2) Start the NuttX build at least one time from the Cygwin command line
before trying to create your project. This is necessary to create
certain auto-generated files and directories that will be needed.
3) Set up include pathes: You will need include/, arch/arm/src/stm32,
arch/arm/src/common, arch/arm/src/armv7-m, and sched/.
4) All assembly files need to have the definition option -D __ASSEMBLY__
on the command line.
Startup files will probably cause you some headaches. The NuttX startup file
is arch/arm/src/stm32/stm32_vectors.S. With RIDE, I have to build NuttX
one time from the Cygwin command line in order to obtain the pre-built
startup object needed by RIDE.
NuttX EABI "buildroot" Toolchain
================================
A GNU GCC-based toolchain is assumed. The files */setenv.sh should
be modified to point to the correct path to the Cortex-M3 GCC toolchain (if
different from the default in your PATH variable).
If you have no Cortex-M3 toolchain, one can be downloaded from the NuttX
SourceForge download site (https://sourceforge.net/projects/nuttx/files/buildroot/).
This GNU toolchain builds and executes in the Linux or Cygwin environment.
1. You must have already configured Nuttx in <some-dir>/nuttx.
cd tools
./configure.sh stm32ldiscovery/<sub-dir>
2. Download the latest buildroot package into <some-dir>
3. unpack the buildroot tarball. The resulting directory may
have versioning information on it like buildroot-x.y.z. If so,
rename <some-dir>/buildroot-x.y.z to <some-dir>/buildroot.
4. cd <some-dir>/buildroot
5. cp configs/cortexm3-eabi-defconfig-4.6.3 .config
6. make oldconfig
7. make
8. Edit setenv.h, if necessary, so that the PATH variable includes
the path to the newly built binaries.
See the file configs/README.txt in the buildroot source tree. That has more
details PLUS some special instructions that you will need to follow if you are
building a Cortex-M3 toolchain for Cygwin under Windows.
NOTE: Unfortunately, the 4.6.3 EABI toolchain is not compatible with the
the NXFLAT tools. See the top-level TODO file (under "Binary loaders") for
more information about this problem. If you plan to use NXFLAT, please do not
use the GCC 4.6.3 EABI toochain; instead use the GCC 4.3.3 OABI toolchain.
See instructions below.
NuttX OABI "buildroot" Toolchain
================================
The older, OABI buildroot toolchain is also available. To use the OABI
toolchain:
1. When building the buildroot toolchain, either (1) modify the cortexm3-eabi-defconfig-4.6.3
configuration to use EABI (using 'make menuconfig'), or (2) use an exising OABI
configuration such as cortexm3-defconfig-4.3.3
2. Modify the Make.defs file to use the OABI conventions:
+CROSSDEV = arm-nuttx-elf-
+ARCHCPUFLAGS = -mtune=cortex-m3 -march=armv7-m -mfloat-abi=soft
+NXFLATLDFLAGS2 = $(NXFLATLDFLAGS1) -T$(TOPDIR)/binfmt/libnxflat/gnu-nxflat-gotoff.ld -no-check-sections
-CROSSDEV = arm-nuttx-eabi-
-ARCHCPUFLAGS = -mcpu=cortex-m3 -mthumb -mfloat-abi=soft
-NXFLATLDFLAGS2 = $(NXFLATLDFLAGS1) -T$(TOPDIR)/binfmt/libnxflat/gnu-nxflat-pcrel.ld -no-check-sections
NXFLAT Toolchain
================
If you are *not* using the NuttX buildroot toolchain and you want to use
the NXFLAT tools, then you will still have to build a portion of the buildroot
tools -- just the NXFLAT tools. The buildroot with the NXFLAT tools can
be downloaded from the NuttX SourceForge download site
(https://sourceforge.net/projects/nuttx/files/).
This GNU toolchain builds and executes in the Linux or Cygwin environment.
1. You must have already configured Nuttx in <some-dir>/nuttx.
cd tools
./configure.sh lpcxpresso-lpc1768/<sub-dir>
2. Download the latest buildroot package into <some-dir>
3. unpack the buildroot tarball. The resulting directory may
have versioning information on it like buildroot-x.y.z. If so,
rename <some-dir>/buildroot-x.y.z to <some-dir>/buildroot.
4. cd <some-dir>/buildroot
5. cp configs/cortexm3-defconfig-nxflat .config
6. make oldconfig
7. make
8. Edit setenv.h, if necessary, so that the PATH variable includes
the path to the newly builtNXFLAT binaries.
LEDs
====
The STM32L-Discovery board has four LEDs. Two of these are controlled by
logic on the board and are not available for software control:
LD1 COM: LD2 default status is red. LD2 turns to green to indicate that
communications are in progress between the PC and the ST-LINK/V2.
LD2 PWR: Red LED indicates that the board is powered.
And two LEDs can be controlled by software:
User LD3: Green LED is a user LED connected to the I/O PB7 of the STM32L152
MCU.
User LD4: Blue LED is a user LED connected to the I/O PB6 of the STM32L152
MCU.
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/up_leds.c. The LEDs are used to encode OS-related
events as follows:
SYMBOL Meaning LED state
LED3 LED4
------------------- ----------------------- -------- --------
LED_STARTED NuttX has been started OFF OFF
LED_HEAPALLOCATE Heap has been allocated OFF OFF
LED_IRQSENABLED Interrupts enabled OFF OFF
LED_STACKCREATED Idle stack created ON OFF
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 OFF Blinking
LED_IDLE STM32 is is sleep mode Not used
Serial Console
==============
The STM32L-Discovery has no on-board RS-232 driver. Further, there are no
USART pins that do not conflict with the on board resources, in particular,
the LCD: Most USART pins are available if the LCD is enabled; USART2 may be
used if either the LCD or the on-board LEDs are disabled.
PA9 USART1_TX LCD glass COM1 P2, pin 22
PA10 USART1_RX LCD glass COM2 P2, pin 21
PB6 USART1_TX LED Blue P2, pin 8
PB7 USART1_RX LED Green P2, pin 7
PA2 USART2_TX LCD SEG1 P1, pin 17
PA3 USART2_RX LCD SEG2 P1, pin 18
PB10 USART3_TX LCD SEG6 P1, pin 22
PB11 USART3_RX LCD SEG7 P1, pin 23
PC10 USART3_TX LCD SEG22 P2, pin 15
PC11 USART3_RX LCD SEG23 P2, pin 14
A USB serial console is another option.
Debugging
=========
STM32 ST-LINK Utility
---------------------
For simply writing to FLASH, I use the STM32 ST-LINK Utility. At least
version 2.4.0 is required (older versions do not recognize the STM32 F3
device). This utility is available from free from the STMicro website.
Debugging
---------
If you are going to use a debugger, you should make sure that the following
settings are selection in your configuration file:
CONFIG_DEBUG_SYMBOLS=y : Enable debug symbols in the build
CONFIG_ARMV7M_USEBASEPRI=y : Use the BASEPRI register to disable interrupts
OpenOCD
-------
I am told that OpenOCD will work with the ST-Link, but I have never tried
it.
https://github.com/texane/stlink
--------------------------------
This is an open source server for the ST-Link that I have never used.
Atollic GDB Server
------------------
You can use the Atollic IDE, but I have never done that either.
STM32L-Discovery-specific Configuration Options
===============================================
CONFIG_ARCH - Identifies the arch/ subdirectory. This should
be set to:
CONFIG_ARCH=arm
CONFIG_ARCH_family - For use in C code:
CONFIG_ARCH_ARM=y
CONFIG_ARCH_architecture - For use in C code:
CONFIG_ARCH_CORTEXM4=y
CONFIG_ARCH_CHIP - Identifies the arch/*/chip subdirectory
CONFIG_ARCH_CHIP=stm32
CONFIG_ARCH_CHIP_name - For use in C code to identify the exact
chip:
CONFIG_ARCH_CHIP_STM32L152RB=y
CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG - Enables special STM32 clock
configuration features.
CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG=n
CONFIG_ARCH_BOARD - Identifies the configs subdirectory and
hence, the board that supports the particular chip or SoC.
CONFIG_ARCH_BOARD=stm32fldiscovery (for the STM32L-Discovery development board)
CONFIG_ARCH_BOARD_name - For use in C code
CONFIG_ARCH_BOARD_STM32FLDISCOVERY=y
CONFIG_ARCH_LOOPSPERMSEC - Must be calibrated for correct operation
of delay loops
CONFIG_ENDIAN_BIG - define if big endian (default is little
endian)
CONFIG_DRAM_SIZE - Describes the installed DRAM (SRAM in this case):
CONFIG_DRAM_SIZE=16384 (16Kb)
CONFIG_DRAM_START - The start address of installed DRAM
CONFIG_DRAM_START=0x20000000
CONFIG_STM32_CCMEXCLUDE - Exclude CCM SRAM from the HEAP
CONFIG_ARCH_IRQPRIO - The STM32L-Discovery supports interrupt prioritization
CONFIG_ARCH_IRQPRIO=y
CONFIG_ARCH_FPU - The STM32L-Discovery does not support a floating point unit (FPU)
CONFIG_ARCH_FPU=n
CONFIG_ARCH_LEDS - Use LEDs to show state. Unique to boards that
have LEDs
CONFIG_ARCH_INTERRUPTSTACK - This architecture supports an interrupt
stack. If defined, this symbol is the size of the interrupt
stack in bytes. If not defined, the user task stacks will be
used during interrupt handling.
CONFIG_ARCH_STACKDUMP - Do stack dumps after assertions
CONFIG_ARCH_LEDS - Use LEDs to show state. Unique to board architecture.
CONFIG_ARCH_CALIBRATION - Enables some build in instrumentation that
cause a 100 second delay during boot-up. This 100 second delay
serves no purpose other than it allows you to calibratre
CONFIG_ARCH_LOOPSPERMSEC. You simply use a stop watch to measure
the 100 second delay then adjust CONFIG_ARCH_LOOPSPERMSEC until
the delay actually is 100 seconds.
Individual subsystems can be enabled:
AHB
----
(GPIOs are always enabled)
CONFIG_STM32_FLITF
CONFIG_STM32_DMA1
CONFIG_STM32_DMA2
APB2
----
CONFIG_STM32_SYSCFG
CONFIG_STM32_TIM9
CONFIG_STM32_TIM10
CONFIG_STM32_TIM11
CONFIG_STM32_ADC1
CONFIG_STM32_SPI1
CONFIG_STM32_USART1
APB1
----
CONFIG_STM32_TIM2
CONFIG_STM32_TIM3
CONFIG_STM32_TIM4
CONFIG_STM32_TIM5
CONFIG_STM32_TIM6
CONFIG_STM32_TIM7
CONFIG_STM32_LCD
CONFIG_STM32_WWDG
CONFIG_STM32_IWDG
CONFIG_STM32_SPI2
CONFIG_STM32_SPI3
CONFIG_STM32_USART2
CONFIG_STM32_USART3
CONFIG_STM32_I2C1
CONFIG_STM32_I2C2
CONFIG_STM32_USB
CONFIG_STM32_PWR -- Required for RTC
CONFIG_STM32_DAC1
CONFIG_STM32_COMP
Timer devices may be used for different purposes. One special purpose is
to generate modulated outputs for such things as motor control. If CONFIG_STM32_TIMn
is defined (as above) then the following may also be defined to indicate that
the timer is intended to be used for pulsed output modulation, ADC conversion,
or DAC conversion. Note that ADC/DAC require two definition: Not only do you have
to assign the timer (n) for used by the ADC or DAC, but then you also have to
configure which ADC or DAC (m) it is assigned to.
CONFIG_STM32_TIMn_PWM Reserve timer n for use by PWM, n=1,..,14
CONFIG_STM32_TIMn_ADC Reserve timer n for use by ADC, n=1,..,14
CONFIG_STM32_TIMn_ADCm Reserve timer n to trigger ADCm, n=1,..,14, m=1,..,3
CONFIG_STM32_TIMn_DAC Reserve timer n for use by DAC, n=1,..,14
CONFIG_STM32_TIMn_DACm Reserve timer n to trigger DACm, n=1,..,14, m=1,..,2
For each timer that is enabled for PWM usage, we need the following additional
configuration settings:
CONFIG_STM32_TIMx_CHANNEL - Specifies the timer output channel {1,..,4}
NOTE: The STM32 timers are each capable of generating different signals on
each of the four channels with different duty cycles. That capability is
not supported by this driver: Only one output channel per timer.
JTAG Enable settings (by default only SW-DP is enabled):
CONFIG_STM32_JTAG_FULL_ENABLE - Enables full SWJ (JTAG-DP + SW-DP)
CONFIG_STM32_JTAG_NOJNTRST_ENABLE - Enables full SWJ (JTAG-DP + SW-DP)
but without JNTRST.
CONFIG_STM32_JTAG_SW_ENABLE - Set JTAG-DP disabled and SW-DP enabled
STM32L-Discovery specific device driver settings
CONFIG_U[S]ARTn_SERIAL_CONSOLE - selects the USARTn (n=1,2,3) or UART
m (m=4,5) for the console and ttys0 (default is the USART1).
CONFIG_U[S]ARTn_RXBUFSIZE - Characters are buffered as received.
This specific the size of the receive buffer
CONFIG_U[S]ARTn_TXBUFSIZE - Characters are buffered before
being sent. This specific the size of the transmit buffer
CONFIG_U[S]ARTn_BAUD - The configure BAUD of the UART. Must be
CONFIG_U[S]ARTn_BITS - The number of bits. Must be either 7 or 8.
CONFIG_U[S]ARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity
CONFIG_U[S]ARTn_2STOP - Two stop bits
STM32L-Discovery CAN Configuration
CONFIG_CAN - Enables CAN support (one or both of CONFIG_STM32_CAN1 or
CONFIG_STM32_CAN2 must also be defined)
CONFIG_CAN_EXTID - Enables support for the 29-bit extended ID. Default
Standard 11-bit IDs.
CONFIG_CAN_FIFOSIZE - The size of the circular buffer of CAN messages.
Default: 8
CONFIG_CAN_NPENDINGRTR - The size of the list of pending RTR requests.
Default: 4
CONFIG_CAN_LOOPBACK - A CAN driver may or may not support a loopback
mode for testing. The STM32 CAN driver does support loopback mode.
CONFIG_CAN1_BAUD - CAN1 BAUD rate. Required if CONFIG_STM32_CAN1 is defined.
CONFIG_CAN2_BAUD - CAN1 BAUD rate. Required if CONFIG_STM32_CAN2 is defined.
CONFIG_CAN_TSEG1 - The number of CAN time quanta in segment 1. Default: 6
CONFIG_CAN_TSEG2 - the number of CAN time quanta in segment 2. Default: 7
CONFIG_CAN_REGDEBUG - If CONFIG_DEBUG is set, this will generate an
dump of all CAN registers.
STM32L-Discovery SPI Configuration
CONFIG_STM32_SPI_INTERRUPTS - Select to enable interrupt driven SPI
support. Non-interrupt-driven, poll-waiting is recommended if the
interrupt rate would be to high in the interrupt driven case.
CONFIG_STM32_SPI_DMA - Use DMA to improve SPI transfer performance.
Cannot be used with CONFIG_STM32_SPI_INTERRUPT.
Configurations
==============
Each STM32L-Discovery configuration is maintained in a sub-directory and
can be selected as follow:
cd tools
./configure.sh STM32L-Discovery/<subdir>
cd -
. ./setenv.sh
If this is a Windows native build, then configure.bat should be used
instead of configure.sh:
configure.bat STM32L-Discovery\<subdir>
Where <subdir> is one of the following:
nsh:
---
Configures the NuttShell (nsh) located at apps/examples/nsh. The
Configuration enables the serial interfaces on UART2. 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:
a. Build and install the kconfig-mconf tool. See nuttx/README.txt
and misc/tools/
b. Execute 'make menuconfig' in nuttx/ in order to start the
reconfiguration process.
2. By default, this configuration uses the CodeSourcery toolchain
for Windows and builds under Cygwin (or probably MSYS). That
can easily be reconfigured, of course.
CONFIG_HOST_WINDOWS=y : Builds under Windows
CONFIG_WINDOWS_CYGWIN=y : Using Cygwin
CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y : CodeSourcery for Windows
3. This configuration includes USB Support (CDC/ACM device)
CONFIG_STM32_USB=y : STM32 USB device support
CONFIG_USBDEV=y : USB device support must be enabled
CONFIG_CDCACM=y : The CDC/ACM driver must be built
CONFIG_NSH_BUILTIN_APPS=y : NSH built-in application support must be enabled
CONFIG_NSH_ARCHINIT=y : To perform USB initialization
The CDC/ACM example is included as two NSH "built-in" commands.\
CONFIG_EXAMPLES_CDCACM=y : Enable apps/examples/cdcacm
The two commands are:
sercon : Connect the serial device a create /dev/ttyACM0
serdis : Disconnect the serial device.
NOTE: The serial connections/disconnections do not work as advertised.
This is because the STM32L-Discovery board does not provide circuitry for
control of the "soft connect" USB pullup. As a result, the host PC
does not know the USB has been logically connected or disconnected. You
have to follow these steps to use USB:
1) Start NSH with USB disconnected
2) enter to 'sercon' command to start the CDC/ACM device, then
3) Connect the USB device to the host.
and to close the connection:
4) Disconnect the USB device from the host
5) Enter the 'serdis' command
4. This example can support the watchdog timer test (apps/examples/watchdog)
but this must be enabled by selecting:
CONFIG_EXAMPLES_WATCHDOG=y : Enable the apps/examples/watchdog
CONFIG_WATCHDOG=y : Enables watchdog timer driver support
CONFIG_STM32_WWDG=y : Enables the WWDG timer facility, OR
CONFIG_STM32_IWDG=y : Enables the IWDG timer facility (but not both)
The WWDG watchdog is driven off the (fast) 42MHz PCLK1 and, as result,
has a maximum timeout value of 49 milliseconds. for WWDG watchdog, you
should also add the fillowing to the configuration file:
CONFIG_EXAMPLES_WATCHDOG_PINGDELAY=20
CONFIG_EXAMPLES_WATCHDOG_TIMEOUT=49
The IWDG timer has a range of about 35 seconds and should not be an issue.
