A complete TFTP (Trivial File Transfer Protocol) client library for Arduino ESP32 and other WiFi-enabled Arduino boards. This library allows you to download files from TFTP servers over WiFi.

TFTP transfer are ideally suited for OTA of systems that spend a lot of time in deep sleep. It does not require complex http server setup as all you need on Linux is:

sudo dnsmasq --port=0 --enable-tftp --tftp-root=/path/to/folder --tftp-no-blocksize --user=root --group=root

If upload to the server is needed, tftp-hpa is easy to install and configure. Just make sure to give the --create parameter.

• Simple API - Easy to use with minimal setup
• Active Download Management - Control downloads with begin/read/end methods
• Active Upload Management - Control uploads with begin/write/end methods
• Robust Protocol Implementation - Full TFTP RFC 1350 compliance
• Error Handling - Comprehensive error reporting and recovery
• Progress Callbacks - Monitor download progress in real-time
• Streaming Uploads - Upload data without storing entire files in memory
• Timeout & Retry Logic - Configurable timeouts and automatic retries

1. Download the library files (TFTPClient.h and TFTPClient.cpp)
2. Place them in your Arduino project directory
3. Include the header in your sketch: #include "TFTPClient.h"

• ESP32, ESP8266, or other WiFi-enabled Arduino board
• WiFi connection
• TFTP server on your network

• TFTP uses UDP port 69 for initial connection
• Data transfer uses a random high port assigned by the server
• Files are transferred in 512-byte blocks (except the last block)
• Each block must be acknowledged before the next is sent
• Binary mode ("octet") is used for all transfers
• Maximum theoretical file size is ~33MB (65535 blocks × 512 bytes)

Several modes of use are possible. They are demonstrated in the examples:

• Small file download: Applicable for files that hold in memory. The buffer needs to be at least as large than the received file
• Passive file download: Easiest way to use the library to process the data as it is received
• Stream download/upload: Enables to use the standard stream methods
• Active download/upload: If you want to manage the transfer on your own

1. Connection Issues

   • Ensure WiFi is connected before calling begin()
   • Check if TFTP server is running and accessible
   • Verify firewall settings allow TFTP traffic

2. Download Failures

   • Check if the file exists on the server
   • Ensure buffer is large enough for the file
   • Try increasing timeout for slow networks

3. Memory Issues

   • Use smaller buffers for large files
   • Process files in chunks if needed
   • Monitor available heap memory