The S3-1200 Finally Boots Like a Real Sampler

Huge thanks to PCBWay for supporting this project and manufacturing the PCBs: https://pcbway.com/g/GWd2X2 In this episode, we officially begin programming the S3-1200 sampler. The first goal is to establish communication between the Control Brain and Audio Brain using UART, build a hardware diagnostic system, and create the first real user interface for the sampler. From there, I implement: -boot diagnostics -project creation/loading -SD card project management -OLED menu navigation -session initialization -active project memory allocation in PSRAM This is the point where the S3-1200 starts feeling less like a collection of PCBs and more like an actual instrument. 🧠 What You’ll See in This Video • UART communication between two ESP32-S3 boards • OLED boot diagnostics • Hardware checks for ADC, DAC, and SD card • Building the New Project / Load Project system • Rotary encoder menu navigation • SD card project folder creation • Project loading workflow • PSRAM audio session allocation • Initial firmware architecture for the S3-1200 ⏱️ Video Chapters 0:00 – Introduction 0:57 – PCBWay Sponsor Segment 2:00 – Programming Preamble 2:34 – Phase 1 Programming: UART + Hardware Diagnostics 8:39 – Phase 1 Testing 9:07 – Phase 2 Programming: Project Menu System 15:24 – Phase 2 Testing 16:21 – Phase 3 Programming: Active Session Memory 20:22 – Phase 3 Testing 21:20 – Final Thoughts + What’s Next 🎛️ About the Project The S3-1200 is a modern DIY re-imagining of the classic E-MU SP-1200, built using ESP32-S3 microcontrollers and modern hardware while preserving the spirit and workflow of the original machine. 🔗 Resources S3-1200 code, schematics, and build files:   / makingmygear   Discord →   / discord   Instagram →   / makingmygear   TikTok →   / makingmygear