# armink/FreeModbus_Slave-Master-RTT-STM32

Add master mode to FreeModbus. | 在 FreeModbus 中添加主机模式

Repository: https://github.com/armink/FreeModbus_Slave-Master-RTT-STM32
Canonical: https://ross.abutalabs.com/products/freemodbus_slave-master-rtt-stm32
Language: C
License: NOASSERTION
License Family: other
Topics: modbus, master, freemodbus
Last push: 2022-12-14T10:11:09+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 4779, "days_push": 1358, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1979, forks 896 (observed 2026-08-28T04:06:01.591240+00:00)

## What it is
An open-source Modbus protocol stack based on FreeModbus that adds a master mode to the traditionally slave-only library, supporting RTU, ASCII, and TCP modes. It runs on bare-metal or RTOS environments (RT-Thread, FreeRTOS, UCOS) and allows master and slave to operate concurrently in the same stack.

## Use cases
- implement a Modbus master on an STM32 microcontroller
- add Modbus RTU master functionality to an embedded firmware project
- run Modbus master and slave on the same device
- port a Modbus protocol stack to FreeRTOS or RT-Thread
- poll holding registers and coils from Modbus slave devices
- build an industrial sensor gateway with Modbus TCP

## When to choose
- you need an open-source Modbus master for embedded C projects
- you want master and slave modes in a single protocol stack
- you target RTOS or bare-metal microcontroller environments
- you need blocking or non-blocking request modes with configurable timeouts

## When to avoid
- you need a high-level Modbus library on Linux or Windows desktops
- you require a commercially supported or certified protocol stack
- you need Modbus master in a language other than C
- you want a maintained library with active releases and clear licensing

## Facets
- artifact type: library
- maturity: maintenance
- function: embedded, networking, sdk
- domain: embedded-systems, iot
- platform: embedded, c, cpp
- tags: modbus, modbus-master, modbus-slave, freemodbus, rtos, stm32, industrial-automation, serial-communication, automation, rt-thread

## Member repositories
- armink/FreeModbus_Slave-Master-RTT-STM32 (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:01.591240+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T03:04:41.271393+00:00, confidence not recorded.
  - readme: https://github.com/armink/FreeModbus_Slave-Master-RTT-STM32 (fetched 2026-08-28T04:06:01.591240+00:00, sha 4c7a2e611a94)
- Data as of 2026-08-30T08:39:29.467469+00:00.