# DIY-Multiprotocol-TX-Module: a 2.4GHz RC Transmitter Bridge > DIY-Multiprotocol-TX-Module lets a host RC transmitter control compatible 2.4GHz receivers through several RF chips and protocols. It suits builders willing to assemble hardware, load firmware, and follow model-specific setup documentation. **pascallanger/DIY-Multiprotocol-TX-Module** — Multiprotocol TX Module (or MULTI-Module) is a 2.4GHz transmitter module which controls many different receivers and models. - Repository: https://github.com/pascallanger/DIY-Multiprotocol-TX-Module - Website: https://www.rcgroups.com/forums/showthread.php?t=2165676&goto=newpost - Stars: 1,916 · Forks: 483 - Language: C++ - License: GPL-3.0 - Published: 2026-10-16 · Updated: 2026-10-16 · Language: en - Canonical page: https://hysenlabs.com/projects/pascallanger-diy-multiprotocol-tx-module ## Why the MULTI-Module sits between an RC radio and a receiver DIY-Multiprotocol-TX-Module addresses a specific hardware problem: a transmitter radio may understand one control system while the intended receiver expects another. The project places a microcontroller and compatible RF hardware between the host transmitter and the model. The host radio sends its channel and control signals to the MULTI-Module, which converts that input into the communication format expected by the selected receiver. The intended users are RC hobbyists working with helicopters, fixed-wing aircraft, quadcopters, and miniquads. They may already have a transmitter, receiver, or model that would be expensive or impractical to replace solely to obtain another protocol. The module is also aimed at hardware builders because a functioning installation needs a host transmitter, a MULTI-Module, compatible 2.4GHz RF hardware, a physical antenna, and MULTI firmware. This is a hardware bridge, not an application-level controller. Its value depends on the receiver protocol, RF chip type, transmitter wiring, and model configuration all matching. It does not turn an arbitrary receiver into a universal target. The protocol must be implemented in MULTI firmware, and the RF hardware in the transmitter module must match the corresponding hardware used by the receiver. ## The MCU, RF chip, antenna, and protocol path Based on the repository documentation, each operational unit has three principal parts. A host RC transmitter supplies commands. A Multiprotocol transmitter module contains an ATmega328P or STM32 microcontroller and at least one 2.4GHz RF module. A physical antenna completes the RF path. The four RF chip families named by the README are TI CC2500, Nordic NRF24L01, Cypress CYRF6936, and Amiccom A7105. The selected RF module is not interchangeable at the electrical and protocol level. MULTI firmware activates the appropriate RF hardware for a protocol, implements that protocol's receiver communication, and manages binding with the receiver or model. Control data follows a defined path. The microcontroller interfaces with the host transmitter, decodes its signals, selects or enables the relevant RF hardware, and sends the RC commands through the appropriate implementation. For protocols including DSMX and FrSky, the documentation also states that incoming telemetry can be decoded and made available to the host radio. Telemetry availability is conditional, however. The README says the host transmitter's hardware and firmware determine whether the user can actually use that telemetry. This architecture explains both the flexibility and the complexity. One project can address many receiver families, but each family introduces protocol behavior, binding rules, RF hardware expectations, and model-specific configuration. The MULTI-Module changes the compatibility problem, but it does not remove it. ## Choosing between the documented hardware routes The README presents hardware selection as the first major design decision and describes routes in increasing order of difficulty. A ready-made MULTI-Module from Banggood includes a 4-in-1 RF module and an antenna switcher. This is the closest listed option to buying an assembled unit rather than fabricating the electronics. The DIY route uses one of the project's PCB options from OSHPark. Builders then solder the components and RF modules themselves. The two documented PCB options differ in their microcontroller family, with ATmega328P and STM32F1 identified in the introduction. Separate compiling documentation exists for both the ATmega328p Multiprotocol Module and the STM32 Multiprotocol Module, which suggests that firmware setup must follow the selected hardware. A third route converts an OrangeRx DSM2/X Tx module into a MULTI-Module. The repository includes dedicated OrangeRx compiling documentation and an STM32 PCB directory. A parts list, schematic walkthrough, and board configuration sequence should come from the linked hardware and compiling documents. For an adopter, the important choice is not simply ready-made versus DIY. It is whether the complete hardware combination, including RF chips and antenna arrangement, can run the MULTI firmware and support the receiver protocols required by the user's models. ## Obtaining firmware and completing the first supported model setup The README directs new users to the GitHub releases page for firmware downloads and to docs/Advanced_Manually_Setting_ATmega328_Fuses.md for instructions on uploading `.hex` files. It also links to the latest test build. The repository's linked programming document is the authoritative starting point for the ATmega328p route, while docs/Compiling_STM32.md and docs/Compiling_OrangeTx.md cover the other named hardware routes. A first real setup should begin with receiver compatibility. Protocol selection belongs in Protocols_Details.md, while serial, telemetry, and transmitter options are documented separately in docs/Transmitters.md. Channel mapping is covered by docs/Channel_Order.md. After identifying a supported receiver and model family, docs/Models.md provides model-specific setup guidance. The documented result is a host transmitter connected through the MULTI-Module to a compatible receiver. Binding is handled by the relevant protocol implementation. If telemetry is required, the receiver protocol must support it and the host transmitter must also be capable of presenting that telemetry. If the first setup fails, docs/Troubleshooting.md is the repository's designated next reference. This sequence keeps hardware, protocol, transmitter configuration, and model behavior as separate checks instead of treating firmware installation as proof that every receiver will work. ## Where protocol and telemetry support stop The clearest limitation is that protocol support is finite. The README links to a dedicated available-protocols list, so users cannot infer support from the project's broad claim that it controls many receivers and models. A receiver whose protocol is absent from that list is outside the documented capability set. Even when the model family has support, the protocol may impose its own binding sequence or RF hardware requirement. Telemetry has another boundary. The documentation describes MULTI-Module as telemetry capable for protocols that support telemetry, but immediately qualifies the claim by saying that use of the information depends on the radio hardware and firmware. The radio may receive serial or telemetry data without exposing useful telemetry to the pilot. Protocol support and end-to-end telemetry support are therefore different checks. The project is also the wrong choice for someone expecting a USB-only or software-only multiprotocol transmitter. The architecture requires an RC host transmitter, a programmed microcontroller, compatible RF modules, and an antenna. Purchasing an already assembled bridge is still an electronics dependency, while building a PCB introduces soldering and hardware configuration work. Troubleshooting can be difficult to isolate because several boundaries meet at the module: host transmitter output, serial settings, channel order, protocol selection, binding, RF hardware, and physical radio operation. The repository has a troubleshooting guide. Automated protocol detection, rollback behavior, and a compatibility-checking application should not be assumed. ## MULTI-Module versus a purpose-built RC radio system The practical alternative is a purpose-built RC transmitter and receiver sold as a matched protocol system. Such a system sends control data using a protocol implemented by both radio endpoints and normally provides vendor-defined setup paths for supported models. Its advantage is a narrower compatibility problem: the radio and receiver were designed around the same system rather than depending on a bridge assembled from separate components. MULTI-Module takes a different approach. It preserves an existing host transmitter and places MULTI firmware, a microcontroller, and interchangeable RF hardware in the signal path. That can be useful when the user has several receiver families or wants to retain an existing transmitter. The cost of that flexibility is a larger compatibility matrix. The user must align the host transmitter, MCU board, RF chip, antenna, firmware protocol, channel order, and model configuration. A ready-made MULTI-Module reduces assembly compared with a DIY board but does not eliminate those configuration checks. A DIY board lowers reliance on an off-the-shelf module assembly but adds soldering and hardware selection. Neither route changes the documented requirement that the RF hardware types correspond between transmitter and receiver. Buyers who value immediate model coverage over reusing a host transmitter may prefer the matched native system; builders who need cross-protocol reuse are the group for which MULTI-Module makes more sense. ## Maintenance, releases, and GPL-3.0 distribution The repository is not archived, and its last push was on 2026-09-22. Recent listed releases include v1.3.4.63 on 2026-08-04, v1.3.4.31 on 2025-02-14, and v1.3.4.0 on 2024-03-18. These dates show recent repository activity and published firmware releases, but they do not establish support for every protocol or model. Upgrade planning must account for hardware as well as firmware. The repository separates build instructions for ATmega328p, STM32, OrangeRx, and board support, while the introduction identifies ATmega328P and STM32 as the current microcontroller choices. A release may require a particular hardware route and programming procedure, so an upgrade should begin with the document matching the installed board. The README also distinguishes latest test builds from releases. That makes test builds useful for tracking current changes. The repository is licensed under GPL-3.0. That matters for people who modify or redistribute the firmware or associated source, although this review does not interpret the license for a particular distribution. Anyone packaging binaries, selling modified hardware, or publishing changes should inspect the repository's LICENSE and assess the applicable source-availability and notice obligations. ## Conclusion DIY-Multiprotocol-TX-Module fits builders who need one host transmitter to operate multiple compatible receiver families and can manage its hardware and firmware setup. It is a poor fit for plug-and-play users, unsupported models, or systems that require a matching native radio system. Before adoption, verify that the required receiver protocol appears in Protocols_Details.md, that the selected RF hardware is supported, and that the transmitter configuration is covered by docs/Transmitters.md. ## FAQ ### What hardware does a DIY-Multiprotocol-TX-Module installation require? It requires a host RC transmitter, a MULTI-Module containing an ATmega328P or STM32 and at least one RF module, MULTI firmware, and a physical 2.4GHz antenna. ### Does DIY-Multiprotocol-TX-Module provide telemetry for every receiver? No. Telemetry applies to protocols that support it, and actual availability also depends on the host radio's hardware and firmware. ### How do I find out whether my receiver model is supported? Check Protocols_Details.md for protocol availability, then use docs/Models.md for model-specific setup and docs/Transmitters.md for transmitter configuration. ## Sources - [License: GPL-3.0](https://github.com/pascallanger/DIY-Multiprotocol-TX-Module/blob/master/LICENSE) - [pascallanger/DIY-Multiprotocol-TX-Module on GitHub](https://github.com/pascallanger/DIY-Multiprotocol-TX-Module) - [Project website](https://www.rcgroups.com/forums/showthread.php?t=2165676&goto=newpost) - [README](https://github.com/pascallanger/DIY-Multiprotocol-TX-Module/blob/master/README.md) - [Releases](https://github.com/pascallanger/DIY-Multiprotocol-TX-Module/releases) --- Hysen Labs editorial analysis, written from the project's own repository and release notes. Cite the canonical page: https://hysenlabs.com/projects/pascallanger-diy-multiprotocol-tx-module