modm: a barebone embedded library generator¶
modm (pronounced like dial-up "modem") is a toolbox for building custom C++23 libraries tailored to your embedded device. modm generates startup code, HALs and their implementations, communication protocols, drivers for external devices, and BSPs in a modular, customizable process that you can fine-tune to your needs.
- Install the toolchain and explore our examples.
- You can discover the modm library in more detail.
- Easily start your own completely custom project.
- Our CI checks every contribution for regressions.
- We care about testing modm.
- API reference is available here.
- We do quarterly releases with a curated changelog.
This project also has a forum for discussions and a technical blog to document larger design concepts.
- You found a bug? Open up an issue, we don't bite.
- You have a question? We probably have an answer.
- You require a feature? Write it down to get things rolling.
- You want to contribute? Read the contribution guidelines and open a pull request.
modm is optimized for the harsh requirements of the Eurobot competition, where our robots need to run reliably and completely autonomously for the game's 100 second duration. Our robots contain a lot of different microcontrollers, some without a lot of resources, so modm needs to fulfill a diverse set of objectives, like small code size with small memory consumption, predictable program flow, extreme portability.
The library source code is licensed as MPLv2 with any external source code under compatible licenses (BSD, Apache2, MIT). So feel free to fork this project and adapt it to your needs. The only thing we ask of you is to contribute your changes back so everyone can benefit.
Please clone modm recursively, you need all the submodules:
git clone --recurse-submodules --jobs 8 https://github.com/modm-io/modm.git
Features¶
- Efficient and fast object-oriented C++23 API.
- Support for thousands of AVR and ARM Cortex-M microcontrollers from Microchip, STMicroelectronics and Raspberry Pi.
- Build system agnostic: Choose SCons, CMake, Makefile or use your own.
- Modular, data-driven, target-specific HAL generation using the lbuild code generator.
- No memory allocations in HAL with very low overall RAM consumption.
- Highly configurable modules with sensible defaults and lots of documentation.
- Cross-platform peripheral interfaces incl. bit banging:
- GPIO, External Interrupt and IO expanders.
- ADC, DAC and Comparators.
- UART, I2C, SPI, CAN and Ethernet.
- Interfaces and drivers for many external I2C and SPI sensors and devices.
- Debug/logging system with IOStream and printf interface.
- Cooperative, stackless protothreads and resumable functions.
- Cooperative, stackful fibers and scheduler.
- Functional (partial) libstdc++ implementation for AVRs.
- Useful filter, interpolation and geometric algorithms.
- Lightweight unit testing system (suitable for AVRs).
- Hundreds of tests to ensure correct functionality.
- Integration of useful third-party software:
- FreeRTOS and FreeRTOS+TCP operating system.
- CMSIS and CMSIS-DSP interfaces.
- ETL: Embedded Template Library.
- TinyUSB: USB Host/Device stack.
- FatFS: FAT/exFAT filesystem.
- ROSserial: Embedded ROS client.
- CrashCatcher: Crash reports for HardFaults.
- printf: Small printf implementation.
- Nanopb: Embedded Protocol Buffers.
- LVGL: Embedded Graphics Library.
Microcontrollers¶
modm can create a HAL for 3839 devices of these vendors:
- STMicroelectronics STM32: 3034 devices.
- Microchip SAM: 416 devices.
- Microchip AVR: 388 devices.
- Raspberry Pi: 1 device.
Here is a table with all device families and the peripheral drivers they support:
- ✅ Implemented as a software driver in modm.
- â—‹ Available in hardware but missing a software driver in modm.
- ✕ Unavailable in hardware or device with that peripheral not supported by modm.
Note that this is a summary overview and your specific device may not have all the peripherals in this table. Please discover modm's peripheral drivers for your specific device.
| STM32 | SAM | RP | AT | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Peripheral | C0 | F0 | F1 | F2 | F3 | F4 | F7 | G0 | G4 | H7 | L0 | L1 | L4 | L5 | U5 | D1x D2x DAx |
D5x E5x |
E7x S7x V7x |
G5x | 20 | 90 | Mega | Tiny |
| ADC | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ○ | ✅ | ✅ | ✅ | ○ | ○ | ○ | ✅ | ✅ | ✅ | ○ | ✅ | ✅ |
| CAN | ✕ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✕ | ✕ | ✅ | ✅ | ✅ | ✕ | ○ | ✅ | ✕ | ✕ | ○ | ○ | ✕ |
| Comparator | ✕ | ○ | ✕ | ✕ | ✅ | ✕ | ✕ | ✅ | ✅ | ○ | ○ | ○ | ✅ | ○ | ○ | ○ | ○ | ○ | ✕ | ✕ | ○ | ○ | ○ |
| DAC | ✕ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ○ | ○ | ✅ | ✕ | ✕ | ✕ | ○ | ✕ |
| DMA | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ○ | ○ | ○ | ✅ | ✕ | ✅ | ✕ | ✕ | ✕ |
| Ethernet | ✕ | ✕ | ○ | ○ | ✕ | ✅ | ✅ | ✕ | ✕ | ○ | ✕ | ✕ | ✕ | ✕ | ✕ | ✕ | ○ | ○ | ✕ | ✕ | ✕ | ✕ | ✕ |
| External Interrupt | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ○ | ○ | ○ | ✅ | ✅ | ✅ | ✅ |
| External Memory | ✕ | ✕ | ✅ | ✅ | ✕ | ✅ | ○ | ✕ | ○ | ○ | ✕ | ✕ | ○ | ○ | ○ | ✕ | ✕ | ○ | ✕ | ✕ | ✕ | ✕ | ✕ |
| GPIO | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
| I2C | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ○ | ○ | ✅ | ○ | ✅ | ✅ | ✅ | ✅ |
| Internal Flash | ○ | ○ | ✅ | ○ | ○ | ✅ | ○ | ✅ | ✅ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ✕ | ✕ | ✕ | ✕ |
| IWDG | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✕ | ✕ | ✕ | ✕ | ✕ | ✕ | ✕ | ✕ |
| Random Generator | ✕ | ✕ | ✕ | ✅ | ✕ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✕ | ✅ | ✅ | ✅ | ✕ | ○ | ○ | ✕ | ✕ | ✕ | ✕ | ✕ |
| SPI | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ○ | ○ | ○ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
| System Clock | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✕ | ✕ | ✕ |
| Timer | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ○ | ○ | ✅ | ✅ | ○ | ○ | ○ | ○ |
| UART | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ○ |
| Unique ID | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✕ | ✕ | ✕ | ✕ | ✕ | ✕ | ✕ | ✕ |
| USB | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✕ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ○ | ✅ | ✅ | ✕ | ✕ | ✕ |
We are only a small team of developers and are limited in the amount of devices we can support and test in hardware. Open a discussion to ask if your specific device is supported out-of-the-box and how you can add it otherwise.
Boards¶
We have out-of-box support for many development boards including documentation.
Drivers¶
We also have a number of completely target-independent drivers for external devices connected via I2C, SPI, UART, BitBang, etc. Most of these also give you access to the entire device so you can easily configure them for your specific needs.
Examples¶
We have a huge number of examples which are always up-to-date and compilable as enforced by our CI.