PIC Modbus Data Decoder

@cnarvaez1957

Hello... I can help... I have over 20 years of experience working with PIC Micro. I have worked on Modbus RTU implementations, both hardware and software. I work with MPLAB X and its C compilers, particularly XC8. I can review your code confidentially and without obligation. Feel free to contact me. Please check my profile. Best regards

@elect2eng

hello, I am a pic microcontroller programmer with expertise for programming in C using MPLABX. I will be able to help you with task of adding MODBUS RTU. Can you please send me the details of the project so that we can start discussion.

@mahads31

As a seasoned web and software developer with a strong expertise in C programming, I have the necessary knowledge to help decode your Modbus RTU frames and pull out the needed information using a compact yet well-structured approach. I am also no stranger to working with microcontrollers such as PIC and have abundant experience utilizing peripherals like EUSART and DMA. What distinguishes me from other potential candidates is my deep commitment to delivering not just satisfactory results but valuable solutions that grow alongside your business. To ensure this, I cultivate a client-centered approach, where I take the time to understand not only the technical requirements but also the underlying business goals. In this project, I will thoroughly document the resulting byte-to-register mapping so that it can be easily adapted for future devices with minimal guesswork. Lastly, I prioritize practical innovation without compromising quality. Rest assured that, besides providing you with an efficient deliverable promptly – ready for immediate integration – my solution will offer clarity and portability of code, rather than unnecessary bells and whistles. Let's build a dependable system to decode your Modbus RTU frames while envisioning long-term value and scalability for your business.

@sivom

Hi, I am from Chennai. I have worked with Microchip PIC. Please share the detailed document about the Modbus messages , from which Modbus device you are collecting the data, Can we discuss in detail to proceed further in chat or direct Regards Senthil Chennai

@nevorek

Good day. I have needed hardware for develop and test program. You can look at portfolio that i have required experience, which include writing firmware for industrial hardware with MODBUS interface. You will get well usable and documented software.

@cesur135

As an experienced engineer in the field of industrial automation, I have in-depth knowledge leveraging the Modbus protocol not only for controlling several pieces of equipment but also implementing efficient monitoring and response protocols. I have utilized similar tools you mentioned like EUSART, DMA, tight ISR-based protocols for optimized data handling. I am adept at writing clean and organized code which would be extremely beneficial in significant projects like yours, where not only is real-time parsing vital but so is the ability to add future functionalities. Moreover, my extensive knowledge of different industrial automation platforms such as Siemens TIA Portal program, Simatic Manager program, and WinCC SCADA program, will help me provide a solution that is adaptable and scalable. Additionally, I'm familiar with writing concise yet comprehensive annotated source comments that minimize future guesswork and facilitate easy integration. Data integrity is the core characteristic of any communication protocol and my experience working with CRC or framing faults will ensure your PIC-based controller complies impeccably.

@JPACHECO28

Hi, I have worked extensively with Modbus RTU on PIC microcontrollers and other embedded platforms, and this is exactly the type of firmware work I have delivered before. I implemented Modbus frame parsing, CRC validation, exception handling, and register mapping for industrial devices communicating over RS-485, I have even wrote my own Modbus libraries, I am comfortable working directly with PIC and optimizing code for real-time performance and limited memory environments. For your project, I can provide a clean, lightweight Modbus RTU decoder that integrates into your existing transport layer, supports function codes 03, 04, 06, and 16, and exposes decoded register data , the code will be well documented, easy to extend with additional function codes, and include test frames and validation examples to demonstrate correct operation. My focus is on delivering reliable, maintainable firmware that can be dropped into your existing project with minimal integration effort. Please check my reviews 100% satisfaction warranty, thank you.

@Hrolgar

Modbus RTU's frame boundaries rely on inter-frame silence (3.5 character times at your baud rate), not a start byte, so the decode layer needs to track idle gaps correctly or you end up stitching two frames into one valid-looking garbage frame. Here's how I'd build this for the PIC: a lightweight state machine tied to a timer interrupt that resets on each received byte and fires an end-of-frame callback when the silence threshold passes. CRC16 validation (Modbus uses the 0xA001 reflected polynomial) runs before any register parsing, so corrupted frames get discarded cleanly. Register-to-engineering-unit mapping lives in a config table so you can add or change mappings without touching the parser logic. The host-side harness is what makes the PIC side trustworthy. Feed it known Modbus captures, verify decoded output, then flash knowing the parser is clean. Much easier than chasing a parsing bug through a live UART trace. M1: Frame sync state machine + CRC16 decode + host test harness, INR 16,000, 3d. M2: Register mapping layer, engineering unit conversion, PIC integration, INR 16,000, 2d. What baud rate and which register ranges are you decoding? That'll let me size the mapping table and dial in the inter-frame timer correctly.

@alluankit01

Hi, I can write a compact and clean Modbus RTU decoder for your existing PIC firmware using XC8 / MPLAB X. The best solution is to keep the decoder lightweight and portable: parse validated RTU frames, support function codes 03, 04, 06, and 16, map addresses/payload bytes into usable registers, and expose the decoded result through a simple callback/API for your application layer. I’ll also handle Modbus exception responses, CRC/framing fault flags, and structure the code so adding more function codes later is easy. I have experience with embedded C, PIC firmware structure, UART/EUSART-based communication, ISR-safe data handling, protocol parsing, and clear firmware documentation. I’ll include annotated source comments, byte-to-register mapping notes, and a small test frame set/harness so you can verify the decoder quickly on your PIC development board. I can keep the implementation practical, readable, and easy to integrate into your current project. Best regards Ankit

@shubhankar1967

Hi, I am an IITian with 10+ years of experience to develop similar projects ,I will implement a lean Modbus RTU decoder in C for XC8 (MPLAB X) using a state-machine parser that consumes byte streams from your existing UART ISR, validates function codes 03/04/06/16, and populates typed structs (holding registers, coils, write confirmations) with zero dynamic allocation. The decoder will use a circular buffer interface, return parsed frames via callback or polling flag, and fit within typical PIC18/PIC24 constraints with modular separation between frame parsing and application-layer data mapping. Kindly click on the chat button so I can share you my relavant projects. Lets connect

@briana218

Hi, You're already handling the transport layer and CRC, so the real gap is a clean decoding layer that translates function codes, addresses, and payloads into something your firmware can safely consume without extra overhead or fragile parsing logic. I’ve built similar ISR-driven protocol handlers for embedded systems using XC8 on PIC devices, including Modbus-style framed communication where timing, memory limits, and reliability matter more than anything else. In one project, I reduced parsing latency by structuring a byte-stream state machine that avoided blocking reads and kept ISR work minimal while still supporting multiple function codes and clean callback dispatch into application logic.

@alexbpo

Subject: Proposal Submission for PIC Modbus Data Decoder The key focus in this project is ensuring the platform remains scalable, maintainable, and aligned with your business objectives from the outset. One advantage I bring is access to a broader technical delivery network through my BPO operations. This allows me to support not only the immediate requirements of the project but also related areas such as web applications, mobile apps, e-commerce, AI solutions, ERP/SAP systems, and custom SaaS development if your needs expand in the future. Even if we do not end up working together, you will still leave with a free consultation and clearer direction for the project architecture and implementation strategy. Regards, Alex

@aburaihans3

Hello, I understand you need a compact Modbus RTU decoder module for a PIC-based system using XC8/MPLAB X that can integrate directly into your existing firmware. My approach: ✔ Modbus RTU Frame Parser (PIC / XC8) Real-time frame parsing from UART/EUSART buffer State-machine based decoder for robustness in ISR-driven environments CRC validation integration with your existing layer ✔ Supported Function Codes FC03 (Read Holding Registers) FC04 (Read Input Registers) FC06 (Write Single Register) FC16 (Write Multiple Registers) Extensible structure for additional function codes ✔ Data Handling Layer Clean register mapping to variables or structs Callback/API layer for application consumption Event-driven architecture for decoded packets ✔ Error Handling CRC mismatch detection Frame timeout handling Exception response parsing (Modbus error codes) ✔ Deliverables XC8-compatible C source code (modular, lightweight) Clear API for integration into PIC firmware Annotated documentation explaining frame structure & mapping Simple test frame set / simulation data for validation ✔ Design Focus Minimal RAM/Flash usage (embedded-optimized) ISR-safe buffering strategy Portable structure for reuse across PIC variants Timeline: Core decoder: 2–4 days Testing + integration notes: 1–2 days I can start immediately and adapt the implementation to your existing UART/ISR structure once you share the current transport layer. Best regards

@letswork92

Understanding the challenge of effectively decoding Modbus RTU traffic on your PIC-based controller is crucial for your project’s success. With over 12 years of experience in embedded systems and proficiency with the XC8/MPLAB X toolchain, I can develop a robust decoder that handles function codes 03, 04, 06, and 16 while allowing easy extension for future needs. My approach will include real-time parsing of incoming frames and a clean API or callback mechanism for seamless integration into your existing firmware. Additionally, I will ensure proper error handling for CRC and framing issues to enhance reliability. The accompanying documentation will provide clear byte-to-register mappings to facilitate future adaptations. Given my extensive background with PIC peripherals like EUSART and DMA, I'm confident in delivering a solution that meets your requirements without unnecessary complexity. To further tailor the implementation, could you specify any particular hardware constraints or performance benchmarks you have in mind?

@zainkCE

I have extensive experience in DMA, and ISR routines. I have designed embedded devices and firmware that works on a primaritly STM platform but can adapt quickly. I have lots of open source work and I provide lots of comments and clear documentation.

@JoseRCarvas

The core challenge is translating raw Modbus RTU frames into actionable variables inside your existing PIC firmware without bloating the codebase or breaking real-time constraints. I would build this as a lightweight state-machine decoder using XC8, mapping function codes 03, 04, 06, and 16 to a callback-based API that feeds your application layer. Error responses would trigger a dedicated flag set rather than halting parsing, keeping the main loop responsive. A key question: are your incoming frames fixed-length or variable-length, and do you need the decoder to handle inter-frame gaps in the UART buffer to avoid false starts on partial data?

@pkuyora

Hi, I’m an embedded C engineer with hands-on experience in time-critical industrial communication protocol development, including Modbus RTU and PROFIBUS-DP. Most of my protocol work has been on TI DSP platforms, but I also have some experience with PIC development and can adapt quickly to the XC8/MPLAB X environment. For your PIC Modbus RTU decoder, I can deliver clean and maintainable code that parses the required function codes, exposes decoded address/data/status through a simple API or callback, and properly handles CRC, framing, timeout, and exception responses. Implementation-wise, I would use a lightweight state-machine parser, with double buffering or a ring buffer depending on the PIC model and baud rate. Please share the target PIC part number and baud rate, and I can align the decoder with your existing firmware.

@carson86

Hi, Your transport layer and CRC are already solid — what you need is a clean decoder layer sitting on top. Well-defined, self-contained firmware task. My approach (XC8 / MPLAB X): • State-machine parser consuming bytes from your EUSART receive buffer (ISR-safe, ring-buffer compatible). Silent interval detection handles RTU frame boundaries. • FC03, FC04, FC06, FC16 implemented as first-class handlers. New function codes added by registering a callback in a dispatch table — no changes to the core parser needed. • Decoded payload exposed via a struct and optional callback: on_frame_received(ModbusFrame *f) — your application layer immediately gets slave address, FC, register start, count, and data array. • Exception responses (FC | 0x80) detected and flagged with exception code; CRC or framing faults set an error enum and call an optional on_error() hook. • Annotated source explains every byte offset and register mapping. Test harness with 6–8 pre-captured RTU frames (valid + faulty) proves end-to-end correctness. I've implemented UART-based protocols on microcontrollers and worked directly with Modbus RTU framing before. Delivering clean, portable C — no dependencies beyond stdint.h. Best, Ting-Jui Chou

@LiamRum

As a seasoned freelance developer specializing in embedded systems, I am excited about the opportunity to work on your PIC Modbus Data Decoder project. With extensive experience in PIC peripherals like EUSART and ISR-based protocols, I am confident in my ability to deliver a robust and efficient solution. I will create a compact and well-structured decoder that seamlessly integrates into your existing project, parsing Modbus RTU frames in real time. By supporting essential function codes and ensuring error handling, I will provide a simple API for immediate data consumption. Additionally, I will document the byte-to-register mapping for future adaptability and provide a test harness for validation. I know it may seem like a shot in the dark considering my lack of reviews on Freelancer, but send a message, and I can make your ideas a reality. Worst-case scenario, you still get a free consultation.