PlatformIO is an open-source ecosystem for embedded development.
It has a built-in library manager and is Arduino-compatible. It supports most operating systems; Windows, MacOS, Linux 32 and 64-bit, ARM, and X86.
And best of all, MicroCore is supported!
- What is PlatformIO?
- PlatformIO IDE
- Getting started with PlatformIO IDE or PlatformIO command line interface
- Advanced functionality
- Project Examples
MicroCore and PlatformIO go great together. You can upload using your favorite programmer and print to the serial monitor. But you can also let PlatformIO calculate the fuses and load the correct bootloader file, just like Arduino IDE does!
PlatformIO uses the information provided in platformio.ini to calculate what fuse bits and what bootloader file to load.
Simply provide enough information and run the following commands:
; Set fuses
pio run -t fuses -e set_fuses
; (where "set_fuses" can be replaced with a different environment to match your build configuration)
pio run -t bootloader -e fuses_bootloader
; (where "fuses_bootloader" can be replaced with a different environment to match your build configuration)
You can find a platformio.ini template you can use when creating a project for the ATtiny13 below.
The most common functionality is available in this template. As you can see, the template is divided into multiple environments.
- The default build environment is defined under
[platformio]. - All parameters that are common for all environments are defined under
[env]. - Use the
[env:Upload_ISP]to upload to your target using an ISP programmer. - Use the
[env:Upload_UART]to upload to your target using a USB to serial interface. - Use
[env:set_fuses]to set the fuses. - Use
[env:fuses_bootlaoder]to set the fuses and flash the bootloader.
More information on what each line means can be found further down on this page.
; PlatformIO template project configuration file for MicroCore
; https://github.com/MCUdude/MicroCore/
;
; Build options: build flags, source filter
; Hardware options: oscillator type, BOD, EEPROM retain
; Upload options: programmer type, and extra flags
; Library options: dependencies, extra library storage
; Advanced options: extra scripting
;
; Please see the documentation for the other options
; https://github.com/MCUdude/MicroCore/blob/master/PlatformIO.md
; https://docs.platformio.org/page/projectconf.html
; https://docs.platformio.org/en/latest/platforms/atmelavr.html
[platformio]
default_envs = Upload_ISP ; Default build target
; Common settings for all environments
[env]
platform = atmelavr
framework = arduino
; TARGET SETTINGS
; Chip in use
board = ATtiny13A
; Clock frequency in [Hz]
board_build.f_cpu = 9600000L
; BUILD OPTIONS
; Extra build flags
build_flags =
; Uflag existing flags
build_unflags =
; SERIAL MONITOR OPTIONS
; Serial monitor port defined in the Upload_UART environment
monitor_port = ${env:Upload_UART.upload_port}
; Serial monitor baud rate
monitor_speed = 115200
; Run the following command to upload with this environment
; pio run -e Upload_ISP -t upload
[env:Upload_ISP]
upload_protocol = custom ; Custom upload procedure
upload_flags = ; Avrdude upload flags
-C$PROJECT_PACKAGES_DIR/tool-avrdude/avrdude.conf
-p$BOARD_MCU
-PUSB
-cusbasp
-Uflash:w:$SOURCE:i
upload_command = avrdude $UPLOAD_FLAGS ; Avrdude upload command
; Run the following command to upload with this environment
; pio run -e Upload_UART -t upload
[env:Upload_UART]
upload_protocol = urclock ; Serial bootloader protocol
board_upload.maximum_size = 768 ; Bootloader occupies 256 bytes of flash
upload_port = /dev/cu.usbserial ; User-defined serial upload port
board_upload.speed = ${env:fuses_bootloader.board_bootloader.speed} ; Bootloader baud rate
upload_flags = ; Do not store any program metadata in flash
-xnometadata
; Run the following command to set fuses with no bootloader
; pio run -e set_fuses -t fuses
[env:set_fuses]
board_hardware.uart = no_bootloader
board_hardware.oscillator = internal ; Oscillator type
board_hardware.bod = 2.7v ; Set brown-out detection
board_hardware.eesave = yes ; Preserve EEPROM when uploading using programmer
upload_protocol = usbasp ; Use the USBasp as programmer
upload_flags = ; Divide SPI clock by 8
-B8
; Run the following command to set fuses and flash a bootloader
; pio run -e fuses -t fuses_bootloader
[env:fuses_bootloader]
extends = env:set_fuses ; Continue where set_fuses left off
board_hardware.uart = swio_rxb1_txb0 ; Software UART, RXD=PB1, TXD=PB0
board_hardware.f_cpu_error = +1.25 ; Percent internal clock error (-10 to 10 in 1.25 steps)
board_bootloader.speed = 57600 ; Set bootloader baud rate
PlatformIO requires the board parameter to be present.
| Target | Board name |
|---|---|
| ATtiny13/A | ATtiny13A |
Specifies the clock frequency in [Hz]. Used to determine what oscillator option to choose. A capital L has to be added to the end of the frequency number. Below is a table with supported clocks for MicroCore. Defaults to 9.6 MHz if not specified.
| Clock speed | Oscillator | board_build.f_cpu |
|---|---|---|
| 20 MHz | External | 20000000L |
| 16 MHz | External | 16000000L |
| 12 MHz | External | 12000000L |
| 8 MHz | External | 8000000L |
| 1 MHz | External | 1000000L |
| 9.6 MHz | Internal | 9600000L (defualt) |
| 4.8 MHz | Internal | 4800000L |
| 1.2 MHz | Internal | 1200000L |
| 600 kHz | Internal | 600000L |
| 128 kHz | Internal | 128000L |
Spefices to use the internal or an external oscillator.
Internal oscillator only works with board_build.f_cpu values
9600000L, 4800000L, 1200000L, 600000L, and 128000L.
| Oscillator option |
|---|
internal (default) |
external |
Specifies the hardware brown-out detection. Use disabled to disable.
| BOD option |
|---|
4.3v |
2.7v (default) |
1.8v |
disabled |
Specifies if the EEPROM memory should be retained when uploading using a programmer. Use no to disable.
| EEPROM retain |
|---|
yes (default) |
no |
Specifies which pins to use for bootloader UART communication.
| Bootloader UART pins | |
|---|---|
no_bootloader (default) |
|
swio_rxb1_txb0 |
RXD = PB1, TXD = PB0 |
swio_rxb0_txb1 |
RXD = PB0, TXD = PB1 |
Compensate for the internal oscillator error. Valid values are -10 to +10 in 1.25 steps
Defaults to 0 (%) if not present, and only applies when board_hardware.oscillator = internal.
Specifies the upload baud rate. Available baud rates are shown in the table below has to correlate with build_board.f_cpu.
Note that if you're using a programmer that communicates with Avrdude with a serial port (Arduino as ISP, STK500, etc.) the board_upload.speed field will interfere with the programmer's baud rate.
In this case, use board_bootloader.speed to set the bootloader baud rate, and board_upload.speed to set the baud rate for the programmer.
| Internal osc. | 76800 | 57600 | 38400 | 19200 | 9600 | 4800 | 2400 | 1200 | 600 | 300 |
|---|---|---|---|---|---|---|---|---|---|---|
9600000L |
X | X | X | X | X | |||||
4800000L |
X | X | X | X | ||||||
1200000L |
X | X | X | X | ||||||
600000L |
X | X | X | X | ||||||
128000L |
X | X | X |
| External osc. | 500000 | 460800 | 250000 | 230400 | 115200 | 57600 | 38400 | 19200 | 9600 | 4800 | 2400 | 1200 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
20000000L |
X | X | X | X | X | X | X | |||||
16000000L |
X | X | X | X | X | X | X | X | ||||
12000000L |
X | X | X | X | X | X | X | X | ||||
8000000L |
X | X | X | X | X | X | X | |||||
1000000L |
X | X | X | X | X | X |
This parameter is used to set compiler flags. You can use this field to change the core settings rather than modifying core_settings.h like you would have to in Arduino IDE.
Here is a list of some settings you can change:
| Flag | Description |
|---|---|
| -DDISABLE_SAFEMODE | Disables safemode, which saves space but is not as "safe". However, If you know what you're doing, like explicitly writing a pin as an output before using the analogWrite() function, you can save a little space. |
| -DADC_PRESCALER_2 -DADC_PRESCALER_4 -DADC_PRESCALER_8 -DADC_PRESCALER_16 -DADC_PRESCALER32 -DADC_PRESCALER_64 -DADC_PRESCALER_128 |
Set the ADC prescaler. If not defined, MicroCore will select the best one based on the F_CPU. Use only one of these flags. |
| -DPWM_PHASE_CORRECT | Use phase-correct PWM generation. Uses fast PWM if not defined |
| -DUART_TX_PIN=B,1 | Change the default UART TX pin. If not defined, it will default to B,0 |
| -DUART_RX_PIN=B,0 | Change the default UART RX pin. If not defined, it will default to B,1 |
| -DINTERRUPT_SERIAL_RX | Use interrupt-based (PCINT) UART receive |
| -DCUSTOM_BAUD_RATE=19200 | Manually set UART baud rate (for Serial.print()).See table below for a table of all supported baud rates vs F_CPU. |
Example:
build_flags = -DDPWM_PHASE_CORRECT -DDISABLE_SAFEMODE
This parameter is used to unflag. If you for some reason don't want to use LTO, you can unflag it like so:
build_unflags = -flto
Specified the Avrdude compatible programmer.
Note that you can divide down the programmer clock speed by adding the -B flag; -B8 will give you 1/8th speed.
Here's a list of some popular programmers:
| Programmer name | Avrdude name | Extra flags needed | Additional information |
|---|---|---|---|
| USBasp | usbasp |
||
| USBtinyUSP | usbtiny |
||
| Arduino as ISP | stk500v1 |
-b19200 |
Serial port must be specified in upload_port |
| AVRISPmkII | avrispmkii |
Specified the programmer serial port.
Only needed for UART-based programmers such as the Arduino as ISP (stk500v1).
Specifies extra Avrdude flags. Note that each flag has to be on their separate line:
upload_flags = -b19200
-B8
-v
PlatformIO detects serial ports automatically. However, if you want to override this you can uncomment monitor_port. Use /dev/[port] on Unix-compatible systems, and use COMx on Windows.
If you're having trouble connecting to the serial port on Windows, try \\.\COMx instead.
Sets the serial monitor baud rate. Defaults to 9600 if not defined.
Here is a list of all supported baud rates for use in the user program, not the bootloader.
See the build_flags section on how you can change the baud rate instead of using the default one:
| Clock & baud | 460800 | 250000 | 230400 | 115200 | 57600 | 38400 | 19200 | 9600 | 4800 | 2400 | 1200 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 20 MHz | X | X | X | X (def.) | X | ||||||
| 16 MHz | X | X | X | X (def.) | X | X | |||||
| 12 MHz | X | X | X (def.) | X | X | ||||||
| 9.6 MHz | X | X | X (def.) | X | X | ||||||
| 8 MHz | X | X | X (def.) | X | X | ||||||
| 4.8 MHz | X | X | X | X (def.) | X | X | X | ||||
| 1.2 MHz | X | X | X (def.) | X | X | X | |||||
| 1 MHz | X | X (def.) | X | X | X | ||||||
| 600 kHz | X | X (def.) | X | X | X | ||||||
| 128 kHz |