micropython/ports/stm32
Jim Mussared e64cda5295 stm32: Add implementation of machine.bitstream.
Hand-written version for M0, and cycle-counter version for everything else.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
2021-08-19 22:50:32 +10:00
..
boards stm32: Add implementation of machine.bitstream. 2021-08-19 22:50:32 +10:00
lwip_inc stm32/lwip_inc: Enable LWIP_NETIF_EXT_STATUS_CALLBACK for mDNS. 2019-09-12 18:08:50 +10:00
mbedtls stm32/mbedtls: Fix compile warning about uninitialized val. 2021-08-10 23:43:25 +10:00
mboot all: Update to point to files in new shared/ directory. 2021-07-12 17:08:10 +10:00
usbdev stm32/usbdev: Fix calculation of SCSI LUN size with multiple LUNs. 2020-07-25 01:12:07 +10:00
usbhost stm32: Remove unneeded HTML release notes from usbdev and usbhost dirs. 2018-05-24 11:28:54 +10:00
Makefile stm32: Add implementation of machine.bitstream. 2021-08-19 22:50:32 +10:00
README.md stm32/README.md: Update supported MCUs, and submodule and mboot use. 2021-07-31 15:12:13 +10:00
accel.c all: Use MP_ERROR_TEXT for all error messages. 2020-04-05 15:02:06 +10:00
accel.h stm32: Change header include guards from STMHAL to STM32 to match dir. 2018-02-15 15:47:04 +11:00
adc.c stm32/adc: Simplify and generalise how pin_adcX table is defined. 2021-07-05 16:03:11 +10:00
adc.h stm32/adc: Allow mboot to use basic ADC functions. 2021-04-30 00:42:59 +10:00
autoflash ports: Make new ports/ sub-directory and move all ports there. 2017-09-06 13:40:51 +10:00
boardctrl.c all: Update to point to files in new shared/ directory. 2021-07-12 17:08:10 +10:00
boardctrl.h stm32/boardctrl: Add constants for reset mode values. 2021-04-30 00:31:35 +10:00
bufhelper.c ports: Convert legacy uppercase macro names to lowercase. 2019-02-12 14:54:51 +11:00
bufhelper.h stm32: Change header include guards from STMHAL to STM32 to match dir. 2018-02-15 15:47:04 +11:00
can.c stm32/Makefile: Change -O0 to -Og for DEBUG=1 builds. 2020-12-07 22:27:38 +11:00
can.h stm32/can: Guard header file by MICROPY_HW_ENABLE_CAN. 2019-09-23 23:45:07 +10:00
dac.c all: Use MP_ERROR_TEXT for all error messages. 2020-04-05 15:02:06 +10:00
dac.h stm32/dac: Rework DAC driver to use direct register access. 2019-04-24 15:51:19 +10:00
dma.c esp32,stm32: Add new machine.I2S class for I2S protocol support. 2021-07-05 23:42:25 +10:00
dma.h esp32,stm32: Add new machine.I2S class for I2S protocol support. 2021-07-05 23:42:25 +10:00
eth.c all: Update to point to files in new shared/ directory. 2021-07-12 17:08:10 +10:00
eth.h stm32/eth: Add low-power mode configuration option. 2021-06-13 12:27:33 +10:00
extint.c all: Use MP_ERROR_TEXT for all error messages. 2020-04-05 15:02:06 +10:00
extint.h stm32: Add initial support for STM32WBxx MCUs. 2019-07-17 16:33:31 +10:00
factoryreset.c stm32/factoryreset: Provide empty create-FS function when FAT disabled. 2020-06-17 00:09:37 +10:00
factoryreset.h stm32: Generalise flash mounting code so it supports arbitrary FS. 2019-11-25 18:10:58 +11:00
fatfs_port.c stm32/fatfs_port: Fix bug when MICROPY_HW_ENABLE_RTC not enabled. 2018-07-14 17:17:46 +10:00
fdcan.c stm32/fdcan: Support maximum timeout of HAL_MAX_DELAY in can_receive. 2020-07-09 00:38:40 +10:00
flash.c stm32/flash: Implement WB55 flash locking. 2020-11-16 17:08:30 +11:00
flash.h stm32/flash: Update flash_get_sector_info to return -1 on invalid addr. 2020-06-30 21:24:28 +10:00
flashbdev.c stm32/flash: Update flash_get_sector_info to return -1 on invalid addr. 2020-06-30 21:24:28 +10:00
font_petme128_8x8.h all: Reformat C and Python source code with tools/codeformat.py. 2020-02-28 10:33:03 +11:00
gccollect.c all: Update to point to files in new shared/ directory. 2021-07-12 17:08:10 +10:00
gccollect.h stm32: In link script, define start of stack separately from heap end. 2019-06-14 15:29:24 +10:00
help.c all: Reformat C and Python source code with tools/codeformat.py. 2020-02-28 10:33:03 +11:00
i2c.c stm32: Add support for a board to reserve certain peripherals. 2020-12-07 17:22:08 +11:00
i2c.h stm32/i2c: Factor I2C finding code to i2c_find_peripheral function. 2020-12-07 17:21:36 +11:00
i2cslave.c stm32/i2cslave: Pass I2C instance to callbacks to support multi I2Cs. 2020-06-26 23:56:45 +10:00
i2cslave.h stm32/i2cslave: Pass I2C instance to callbacks to support multi I2Cs. 2020-06-26 23:56:45 +10:00
irq.c stm32/irq: Clean up irq.h so it does not depend on core uPy defines. 2020-06-22 13:47:15 +10:00
irq.h stm32/irq: Clean up irq.h so it does not depend on core uPy defines. 2020-06-22 13:47:15 +10:00
lcd.c all: Use MP_ERROR_TEXT for all error messages. 2020-04-05 15:02:06 +10:00
lcd.h stm32: Change header include guards from STMHAL to STM32 to match dir. 2018-02-15 15:47:04 +11:00
led.c stm32/led: Support PWM output without TIM3. 2020-09-18 18:37:11 +10:00
led.h stm32: Change header include guards from STMHAL to STM32 to match dir. 2018-02-15 15:47:04 +11:00
machine_adc.c stm32/adc: Allow mboot to use basic ADC functions. 2021-04-30 00:42:59 +10:00
machine_bitstream.c stm32: Add implementation of machine.bitstream. 2021-08-19 22:50:32 +10:00
machine_i2c.c stm32/i2c: Factor I2C finding code to i2c_find_peripheral function. 2020-12-07 17:21:36 +11:00
machine_i2s.c esp32,stm32: Add new machine.I2S class for I2S protocol support. 2021-07-05 23:42:25 +10:00
machine_spi.c ports: Support legacy soft I2C/SPI construction via id=-1 arg. 2020-10-01 12:57:10 +10:00
machine_timer.c stm32/softtimer: Support static soft timer instances. 2021-04-29 16:54:35 +10:00
machine_uart.c all: Update to point to files in new shared/ directory. 2021-07-12 17:08:10 +10:00
main.c ports: Rename USBD_VID/PID config macros to MICROPY_HW_USB_VID/PID. 2021-08-07 23:13:55 +10:00
make-stmconst.py stm32/make-stmconst.py: Allow "[]" chars when parsing source comments. 2021-03-10 23:44:02 +11:00
modmachine.c stm32: Add implementation of machine.bitstream. 2021-08-19 22:50:32 +10:00
modmachine.h esp32,stm32: Add new machine.I2S class for I2S protocol support. 2021-07-05 23:42:25 +10:00
modnetwork.c all: Update to point to files in new shared/ directory. 2021-07-12 17:08:10 +10:00
modnetwork.h stm32/modnetwork: Replace generic netif NIC polling with specific code. 2019-06-03 17:14:34 +10:00
modnwcc3k.c all: Update to point to files in new shared/ directory. 2021-07-12 17:08:10 +10:00
modnwwiznet5k.c all: Update to point to files in new shared/ directory. 2021-07-12 17:08:10 +10:00
modpyb.c all: Update to point to files in new shared/ directory. 2021-07-12 17:08:10 +10:00
modstm.c stm32/rfcore: Add Python API for basic rfcore operations. 2020-10-08 17:37:11 +11:00
moduos.c all: Update to point to files in new shared/ directory. 2021-07-12 17:08:10 +10:00
modusocket.c all: Update to point to files in new shared/ directory. 2021-07-12 17:08:10 +10:00
modutime.c all: Update to point to files in new shared/ directory. 2021-07-12 17:08:10 +10:00
mpbthciport.c all: Update to point to files in new shared/ directory. 2021-07-12 17:08:10 +10:00
mpbthciport.h stm32/mpbthciport: Change from systick to soft-timer for BT scheduling. 2021-06-23 13:14:26 +10:00
mpbtstackport.c stm32: Provide a custom BTstack runloop that integrates with soft timer. 2021-06-23 13:14:26 +10:00
mpbtstackport.h extmod/modbluetooth: Refactor stack/hci/driver/port bindings. 2020-09-08 11:41:31 +10:00
mpconfigboard_common.h stm32/usbd_cdc_interface: Rename USBD_CDC_xx opts to MICROPY_HW_USB_xx. 2021-08-07 23:13:58 +10:00
mpconfigport.h stm32: Add implementation of machine.bitstream. 2021-08-19 22:50:32 +10:00
mpconfigport.mk stm32/mboot: Add support for signed and encrypted firmware updates. 2021-01-18 12:43:01 +11:00
mpconfigport_nanbox.h stm32: Add configuration to build in nanbox mode. 2019-12-27 22:54:53 +11:00
mphalport.c ports: Use common mp_hal_stdout_tx_strn_cooked instead of custom one. 2021-07-08 12:59:31 +10:00
mphalport.h stm32/flash: Make flash C-API reusable, and funcs return an error code. 2020-06-22 14:18:15 +10:00
mpnimbleport.c stm32/mpbthciport: Change from systick to soft-timer for BT scheduling. 2021-06-23 13:14:26 +10:00
mpnimbleport.h extmod/modbluetooth: Refactor stack/hci/driver/port bindings. 2020-09-08 11:41:31 +10:00
mpthreadport.c all: Use MP_ERROR_TEXT for all error messages. 2020-04-05 15:02:06 +10:00
mpthreadport.h py/mpthread.h: Use strong type for mp_thread_set_state() argument. 2020-01-29 17:10:32 +11:00
mpu.h all: Reformat C and Python source code with tools/codeformat.py. 2020-02-28 10:33:03 +11:00
network_lan.c stm32/eth: Add low-power mode configuration option. 2021-06-13 12:27:33 +10:00
network_wiznet5k.c all: Update to point to files in new shared/ directory. 2021-07-12 17:08:10 +10:00
pendsv.c all: Update to point to files in new shared/ directory. 2021-07-12 17:08:10 +10:00
pendsv.h extmod/nimble: Make stm32 and unix NimBLE ports use synchronous events. 2020-11-13 17:19:05 +11:00
pin.c all: Use MP_ERROR_TEXT for all error messages. 2020-04-05 15:02:06 +10:00
pin.h all: Format code to add space after C++-style comment start. 2020-04-23 11:24:25 +10:00
pin_defs_stm32.c stm32/pin_defs_stm32: Fix pin printing to show IN mode correctly. 2020-08-21 13:42:47 +10:00
pin_defs_stm32.h esp32,stm32: Add new machine.I2S class for I2S protocol support. 2021-07-05 23:42:25 +10:00
pin_named_pins.c all: Reformat C and Python source code with tools/codeformat.py. 2020-02-28 10:33:03 +11:00
pin_static_af.h all: Reformat C and Python source code with tools/codeformat.py. 2020-02-28 10:33:03 +11:00
portmodules.h stm32: Change header include guards from STMHAL to STM32 to match dir. 2018-02-15 15:47:04 +11:00
powerctrl.c stm32/powerctrl: Support changing frequency on WB MCUs. 2021-08-07 23:41:20 +10:00
powerctrl.h stm32/powerctrl: Support changing frequency on WB MCUs. 2021-08-07 23:41:20 +10:00
powerctrlboot.c stm32/powerctrl: Support changing frequency on WB MCUs. 2021-08-07 23:41:20 +10:00
pyb_can.c stm32/pyb_can: Add ability to calculate CAN bit timing from baudrate. 2020-12-17 23:01:15 +11:00
pyb_i2c.c stm32: Replace master/slave with controller/peripheral in I2C and SPI. 2021-07-18 11:23:41 +10:00
pyb_spi.c stm32: Replace master/slave with controller/peripheral in I2C and SPI. 2021-07-18 11:23:41 +10:00
pybcdc.inf_template ports: Make new ports/ sub-directory and move all ports there. 2017-09-06 13:40:51 +10:00
pybthread.c all: Reformat C and Python source code with tools/codeformat.py. 2020-02-28 10:33:03 +11:00
pybthread.h all: Reformat C and Python source code with tools/codeformat.py. 2020-02-28 10:33:03 +11:00
qspi.c all: Reformat C and Python source code with tools/codeformat.py. 2020-02-28 10:33:03 +11:00
qspi.h stm32/qspi: Add hardware QSPI driver, with memory-map capability. 2018-03-03 00:17:08 +11:00
qstrdefsport.h all: Add *FORMAT-OFF* in various places. 2020-02-28 10:31:07 +11:00
resethandler.s stm32/main: Rename main to stm32_main and pass through first argument. 2018-03-29 16:15:57 +11:00
resethandler_m0.s stm32: Add support for Cortex-M0 CPUs. 2018-05-28 21:46:20 +10:00
rfcore.c stm32/mpbthciport: Change from systick to soft-timer for BT scheduling. 2021-06-23 13:14:26 +10:00
rfcore.h stm32/flash: Implement WB55 flash locking. 2020-11-16 17:08:30 +11:00
rng.c stm32/rng: Use SysTick+RTC+unique-id to seed pRNG for MCUs without RNG. 2020-10-29 14:14:40 +11:00
rng.h stm32: Change header include guards from STMHAL to STM32 to match dir. 2018-02-15 15:47:04 +11:00
rtc.c all: Update to point to files in new shared/ directory. 2021-07-12 17:08:10 +10:00
rtc.h stm32/rtc.h: Include py/obj.h to make header self contained. 2020-09-10 20:46:40 +10:00
sdcard.c stm32/sdcard: Allow configuring the SDMMC periph used for SD/MMC card. 2021-04-30 00:58:17 +10:00
sdcard.h stm32: Add support for MMC driver, exposed via pyb.MMCard class. 2019-04-01 17:04:43 +11:00
sdio.c stm32/sdio: Fix undefined reference to DMA stream on H7. 2021-07-01 12:21:32 +10:00
sdio.h stm32/sdio: Add functions to re/enable SDIO/SDIOIT. 2021-04-30 01:12:08 +10:00
sdram.c stm32/sdram: Make SDRAM test cache aware, and optional failure with msg. 2021-07-22 16:47:49 +10:00
sdram.h stm32/sdram: Make SDRAM test cache aware, and optional failure with msg. 2021-07-22 16:47:49 +10:00
servo.c stm32/servo: Fix angle and speed methods to work again with -ve args. 2020-09-12 13:47:59 +10:00
servo.h stm32: Change header include guards from STMHAL to STM32 to match dir. 2018-02-15 15:47:04 +11:00
softtimer.c stm32/softtimer: Add soft_timer_reinsert() helper function. 2021-06-23 13:14:26 +10:00
softtimer.h stm32/softtimer: Add soft_timer_reinsert() helper function. 2021-06-23 13:14:26 +10:00
spi.c stm32: Replace master/slave with controller/peripheral in I2C and SPI. 2021-07-18 11:23:41 +10:00
spi.h ports: Add SoftI2C and SoftSPI to machine module where appropriate. 2020-10-01 12:57:10 +10:00
spibdev.c drivers/memory/spiflash: Add MICROPY_HW_SPIFLASH_ENABLE_CACHE option. 2020-12-18 13:39:32 +11:00
stm32_it.c stm32/uart: Add support for LPUART1 on L0, L4, H7 and WB MCUs. 2021-02-21 15:49:32 +11:00
stm32_it.h stm32: Change header include guards from STMHAL to STM32 to match dir. 2018-02-15 15:47:04 +11:00
storage.c stm32/storage: Prevent attempts to read/write invalid block addresses. 2021-03-09 15:32:50 +11:00
storage.h stm32/main: Do extended readblocks call when auto-detecting littlefs. 2020-12-18 13:39:28 +11:00
system_stm32.c stm32/powerctrl: Support using PLLI2C on STM32F413 as USB clock source. 2021-04-07 12:47:21 +10:00
systick.c stm32/systick: Always POLL_HOOK when delaying for milliseconds. 2021-07-22 00:15:36 +10:00
systick.h stm32/mpbthciport: Change from systick to soft-timer for BT scheduling. 2021-06-23 13:14:26 +10:00
timer.c stm32: Add support for a board to reserve certain peripherals. 2020-12-07 17:22:08 +11:00
timer.h stm32: Change header include guards from STMHAL to STM32 to match dir. 2018-02-15 15:47:04 +11:00
uart.c stm32/uart: Support low baudrates on LPUART1. 2021-07-26 13:53:50 +10:00
uart.h stm32/uart: Support low baudrates on LPUART1. 2021-07-26 13:53:50 +10:00
usb.c ports: Rename USBD_VID/PID config macros to MICROPY_HW_USB_VID/PID. 2021-08-07 23:13:55 +10:00
usb.h ports: Rename USBD_VID/PID config macros to MICROPY_HW_USB_VID/PID. 2021-08-07 23:13:55 +10:00
usbd_cdc_interface.c stm32/usbd_cdc_interface: Rename USBD_CDC_xx opts to MICROPY_HW_USB_xx. 2021-08-07 23:13:58 +10:00
usbd_cdc_interface.h stm32/usbd_cdc_interface: Rename USBD_CDC_xx opts to MICROPY_HW_USB_xx. 2021-08-07 23:13:58 +10:00
usbd_conf.c all: Reformat C and Python source code with tools/codeformat.py. 2020-02-28 10:33:03 +11:00
usbd_conf.h stm32/usb: Add support for 2xVCP on L0, L432 and WB MCUs. 2020-06-17 00:09:42 +10:00
usbd_desc.c stm32/usbd_desc: Rename USBD_xxx descriptor opts to MICROPY_HW_USB_xxx. 2021-08-07 23:13:58 +10:00
usbd_desc.h stm32: Change header include guards from STMHAL to STM32 to match dir. 2018-02-15 15:47:04 +11:00
usbd_hid_interface.c all: Reformat C and Python source code with tools/codeformat.py. 2020-02-28 10:33:03 +11:00
usbd_hid_interface.h stm32/usbd_hid_interface: Rewrite USB HID interface code. 2019-07-25 17:42:17 +10:00
usbd_msc_interface.c all: Reformat C and Python source code with tools/codeformat.py. 2020-02-28 10:33:03 +11:00
usbd_msc_interface.h stm32/usbdev: Fix calculation of SCSI LUN size with multiple LUNs. 2020-07-25 01:12:07 +10:00
usrsw.c all: Reformat C and Python source code with tools/codeformat.py. 2020-02-28 10:33:03 +11:00
usrsw.h stm32: Change header include guards from STMHAL to STM32 to match dir. 2018-02-15 15:47:04 +11:00
wdt.c all: Use MP_ERROR_TEXT for all error messages. 2020-04-05 15:02:06 +10:00
wdt.h stm32: Change header include guards from STMHAL to STM32 to match dir. 2018-02-15 15:47:04 +11:00

README.md

MicroPython port to STM32 MCUs

This directory contains the port of MicroPython to ST's line of STM32 microcontrollers. Supported MCU series are: STM32F0, STM32F4, STM32F7, STM32H7, STM32L0, STM32L4 and STM32WB. Parts of the code here utilise the STM32Cube HAL library.

The officially supported boards are the line of pyboards: PYBv1.0 and PYBv1.1 (both with STM32F405), PYBLITEv1.0 (with STM32F411) and PYBD-SFx (with STM32F7xx MCUs). See micropython.org/pyboard for further details.

Other boards that are supported include ST Discovery and Nucleo boards. See the boards/ subdirectory, which contains the configuration files used to build each individual board.

The STM32H7 series has preliminary support: there is a working REPL via USB and UART, as well as very basic peripheral support, but some things do not work and none of the advanced features of the STM32H7 are yet supported, such as the clock tree. At this point the STM32H7 should be considered as a fast version of the STM32F7.

Build instructions

Before building the firmware for a given board the MicroPython cross-compiler must be built; it will be used to pre-compile some of the built-in scripts to bytecode. The cross-compiler is built and run on the host machine, using:

$ make -C mpy-cross

This command should be executed from the root directory of this repository. All other commands below should be executed from the ports/stm32/ directory.

An ARM compiler is required for the build, along with the associated binary utilities. The default compiler is arm-none-eabi-gcc, which is available for Arch Linux via the package arm-none-eabi-gcc, for Ubuntu via instructions here, or see here for the main GCC ARM Embedded page. The compiler can be changed using the CROSS_COMPILE variable when invoking make.

Next, the board to build must be selected. The default board is PYBV10 but any of the names of the subdirectories in the boards/ directory is a valid board. The board name must be passed as the argument to BOARD= when invoking make.

All boards require certain submodules to be obtained before they can be built. The correct set of submodules can be initialised using (with PYBV11 as an example of the selected board):

$ make BOARD=PYBV11 submodules

Then to build the board's firmware run:

$ make BOARD=PYBV11

The above command should produce binary images in the build-PYBV11/ subdirectory (or the equivalent directory for the board specified).

Note that some boards require the mboot bootloader to be built and deployed before flashing the main firmware. For such boards an information message about this will be printed at the end of the main firmware build. Mboot can be built via:

$ make -C mboot BOARD=STM32F769DISC

For more information about mboot see mboot/README.md.

Flashing the Firmware using DFU mode

You must then get your board/microcontroller into DFU (Device Firmware Update) mode.

If you already have MicroPython installed on the board you can do that by calling machine.bootloader() on the board, either at the REPL or using pyboard.py. A nice property of this approach is that you can automate it so you can update the board without manually pressing any buttons.

If you do not have MicroPython running yet, temporarily jumper your board's DFU pin (typ. BOOT0) to 3.3v and reset or power-on the board.

On a pyboard the P1/DFU pin and a 3.3v pin are next to each other (on the bottom left of the board, second row from the bottom) and the reset button is labeled RST.

For the pyboard D-series you can enter the mboot DFU bootloader by holding down the USR button, pressing and releasing the RST button, and continuing to hold down USR until the LED is white (4th in the cycle), then let go of USR while the LED is white. The LED will then flash red once per second to indicate it is in USB DFU mode.

Once the board is in DFU mode, flash the firmware using the command:

$ make BOARD=PYBV11 deploy

This will use the included tools/pydfu.py script. You can use instead the dfu-util program (available here) by passing USE_PYDFU=0:

$ make BOARD=PYBV11 USE_PYDFU=0 deploy

If flashing the firmware does not work it may be because you don't have the correct permissions. Try then:

$ sudo make BOARD=PYBV11 deploy

Or using dfu-util directly:

$ sudo dfu-util -a 0 -d 0483:df11 -D build-PYBV11/firmware.dfu

ST Discovery or Nucleo boards have a builtin programmer called ST-LINK. With these boards and using Linux or OS X, you have the option to upload the stm32 firmware using the st-flash utility from the stlink project. To do so, connect the board with a mini USB cable to its ST-LINK USB port and then use the make target deploy-stlink. For example, if you have the STM32F4DISCOVERY board, you can run:

$ make BOARD=STM32F4DISC deploy-stlink

The st-flash program should detect the USB connection to the board automatically. If not, run lsusb to determine its USB bus and device number and set the STLINK_DEVICE environment variable accordingly, using the format <USB_BUS>:<USB_ADDR>. Example:

$ lsusb
[...]
Bus 002 Device 035: ID 0483:3748 STMicroelectronics ST-LINK/V2
$ export STLINK_DEVICE="002:0035"
$ make BOARD=STM32F4DISC deploy-stlink

Flashing the Firmware with OpenOCD

Another option to deploy the firmware on ST Discovery or Nucleo boards with a ST-LINK interface uses OpenOCD. Connect the board with a mini USB cable to its ST-LINK USB port and then use the make target deploy-openocd. For example, if you have the STM32F4DISCOVERY board:

$ make BOARD=STM32F4DISC deploy-openocd

The openocd program, which writes the firmware to the target board's flash, is configured via the file ports/stm32/boards/openocd_stm32f4.cfg. This configuration should work for all boards based on a STM32F4xx MCU with a ST-LINKv2 interface. You can override the path to this configuration by setting OPENOCD_CONFIG in your Makefile or on the command line.

Accessing the board

Once built and deployed, access the MicroPython REPL (the Python prompt) via USB serial or UART, depending on the board. There are many ways to do this, one of which is via mpremote (install it using pip install mpremote):

$ mpremote

Other options are picocom and screen, for example:

$ picocom /dev/ttyACM0