multipass - a multi-architecture library operating system

multipass is a C++ Library Operating System for a few embedded targets / architectures. As such, it does not provide multi-threading support or similar conveniences. Its objective is similar to the Arduino environment: provide a simple framework for embedded application/driver development and evaluation with a main() and optional loop() function and a text output channel, and then get out of the way as much as possible. It favors simplicity over performance and proper abstraction. Re-using components outside of multipass should be fairly easy.

Application, target / architecture, and drivers are configured using make config (X11, kconfig-qconf) or make nconfig (Terminal, kconfig-nconf). Each application must implement int main(void) and do everything itself from that point on. If the loop or wakeup features are enabled, void loop(void) or void wakeup(void) must be implemented as well.

Getting Started

• make config
• make
• make program
• make monitor

Two helper scripts are provided:

• ./mp is a shortcut for make info and make program (build and flash)
• ./mpm is a shortcut for make info, make program, and make monitor (build, flash, and monitor output)

Flags are passed to each make invocation.

For common applications, the arch and app compile switches can be used, e.g. ./mpm arch=posix app=ledblink

You should see some data about the compilation process, "Hello, world!", and some numbers. As POSIX is not a standalone target (it builds an ELF binary that is executed directly on Linux), you do not need a microcontroller to run it. Terminate execution using Ctrl+C.

Supported Targets

See make config for an up-to-date list. Unless noted otherwise, all targets support GPIO input/output, UART output (typically using the built-in USB-TTL chip of the respective development board), and an optional cycle counter. The following table gives a quick overview over targets and additional features; the remainder of this README covers details.

Target	Clock	Non-Volatile Memory	Volatile Memory	Supported Drivers / Features
ATMega168P	16 MHz	512 KiB Flash + 512 B EEPROM	1 KiB SRAM	I²C, SPI, UART, WS2812B, ADC
ATMega328P	16 MHz	32 KiB Flash + 1 KiB EEPROM	2 KiB SRAM	I²C, SPI, UART, WS2812B, ADC
ATMega2560	16 MHz	256 KiB Flash + 4 KiB EEPROM	8 KiB SRAM	I²C, UART, DMX, ADC
LM4F120H5QR (Cortex-M4F)	80 MHz	48 KiB Flash	4 KiB SRAM
MSP430FR5969	16 MHz	48 (64) KiB FRAM	2 KiB SRAM	I²C, SPI, UART, DMX, ADC
MSP430FR5994	16 MHz	48 (256) KiB FRAM	4 (8) KiB SRAM	I²C, SPI, UART, DMX, ADC
RM46L852 (Cortex-R4F)	160 MHz	1.25 MiB Flash	192 KiB SRAM
STM32F446RE (Cortex-M4)	168 MHz	512 KiB Flash	128 KiB SRAM	I²C
STM32F746ZG (Cortex-M7)	216 MHz	1 MiB Flash	320 KiB SRAM
POSIX	–	–	–	I²C

Supported Architectures

See make config for an up-to-date list.

ATMega168P, ATMega328P (Arduino Nano)

Peripheral communication:

• I²C controller
• SPI controller
• UART input/output
• WS2812B output via Adafruit NeoPixel driver

Hardware features:

• ADC (partially)

ATMega2560

Peripheral communication:

• I²C controller
• UART input/output on USART0 / USART1 / USART2 / USART3
• DMX output on USART1 / USART2 / USART3

Hardware features:

• ADC (partially)

LM4F120H5QR (Stellaris Launchpad)

Peripheral communication:

• UART output

MSP430FR5969 (MSP430FR5969 Launchpad)

Peripheral communication:

• I²C controller on eUSCI_B0
• SPI controller on eUSCI_B0
• UART input/output on eUSCI_A0 / eUSCI_A1
• DMX output on eUSCI_A1

Hardware features:

• ADC (partially)

MSP430FR5994 (MSP430FR5994 Launchpad)

Peripheral communication:

• I²C controller on eUSCI_B1
• SPI controller on eUSCI_B1
• UART input/output on eUSCI_A0
• DMX output on eUSCI_A1 / eUSCI_A2 / eUSCI_A3

Hardware features:

• 20bit mode (use up to 256 KiB FRAM for code and data)
• ADC (partially)

RM46L8 (Hercules RM46L8 Launchpad)

Peripheral communication:

• UART output

STM32F446RE (NUCLEO-F446RE)

Peripheral communication:

• UART output on USART2
• I²C on I2C1 muxed to PB8 / PB9

STM32F746ZG (NUCLEO-F746ZG)

Preliminary support, timers may be incorrect.

Peripheral communication:

• UART output on USART3

POSIX

Runs the selected application as POSIX thread, e.g. under Linux on a Raspberry Pi.

Peripheral communication:

• I²C controller via /dev/i2c
• stdin/stdout

Supported Peripherals

See make config for an up-to-date list.

Sensors

• AM2320 Temperature+Humidity (I²C)
• BME280 Temperature+Humidity+Pressure via Bosch SensorTec driver (I²C)
• BME280 Temperature+Humidity+Pressure+IAQ via Bosch SensorTec driver (I²C)
• CCS811 VOC (I²C)
• HDC1080 Temperature+Humidity (I²C)
• LM75 Temperature (I²C)
• MAX44006 R+G+B+Clear+IR irradiance (I²C)
• MAX44009 illuminance (I²C)
• MPU9250 accelerometer+gyroscope+magnetometer (I²C)
• SCD4x CO₂+Temperature+Humidity (I²C)
• SEN5x PM1.0+PM2.5+PM4.0+PM10+Temperature+Humidity+VOC (I²C)
• VEML6075 UVA+UVB irradiance (I²C)

"VOC" refers to volatile organic compounds; "PM" refers to particulate matter.

Displays

• LS013B4DN04 / 430BOOST-SHARP96 96×96 transflective LCD (SPI)
• Pervasive Aurora Mb V230/V231 4.2" iTC E-Paper Display via EPD Extension Board Gen 2 (SPI)
• SSD1306 128×64 / 128×32 OLED display controller (I²C)

Others

• ADS111x ADC (I²C)
• DS2482 1-Wire Bus Controller (I²C)