# SaltyLab — Ideal Team

## Project
Self-balancing two-wheeled robot using a drone ESP32-S3 BALANCE (ESP32-S3), hoverboard hub motors, and eventually a Jetson Orin Nano Super for AI/SLAM.

## Current Status
- **Hardware:** Assembled — FC, motors, ESC, IMU, battery, RC all on hand
- **Firmware:** Balance PID + hoverboard ESC protocol written, but blocked by USB Serial (CH343) bug
- **Blocker:** USB Serial (CH343) TX stops working when peripheral inits (SPI/UART/GPIO) are added alongside USB on ESP32-S3 — see `legacy/stm32/USB_CDC_BUG.md` for historical context

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## Roles Needed

### 1. Embedded Firmware Engineer (Lead)
**Must-have:**
- Deep ESP-IDF experience (ESP32-S3 specifically)
- USB Serial (CH343) / UART debugging on ESP32-S3
- SPI + UART + USB coexistence on ESP32-S3
- ESP-IDF / Arduino-ESP32 toolchain
- OTA firmware update implementation

**Nice-to-have:**
- ESP32-S3 peripheral coexistence (SPI + UART + USB)
- PID control loop tuning for balance robots
- FOC motor control (hoverboard ESC protocol)

**Why:** The immediate blocker is a USB peripheral conflict on ESP32-S3. Need someone who's debugged ESP32-S3 USB Serial (CH343) issues before — this is not a software logic bug, it's a hardware peripheral interaction issue.

### 2. Control Systems / Robotics Engineer
**Must-have:**
- PID tuning for inverted pendulum / self-balancing systems
- Complementary filter / Kalman filter for IMU sensor fusion
- Real-time control loop design (1kHz+)
- Safety system design (tilt cutoff, watchdog, arming sequences)

**Nice-to-have:**
- Hoverboard hub motor experience
- ELRS/CRSF RC protocol
- ROS2 integration

**Why:** Once USB is fixed, the balance loop needs real-world tuning. PID gains, filter coefficients, motor response curves, safety margins — all need someone with hands-on balance bot experience.

### 3. Perception / SLAM Engineer (Phase 2)
**Must-have:**
- Jetson Orin Nano Super / NVIDIA Jetson platform
- Intel RealSense D435i depth camera
- RPLIDAR integration
- SLAM (ORB-SLAM3, RTAB-Map, or similar)
- ROS2

**Nice-to-have:**
- Person tracking / following
- Obstacle avoidance
- Nav2 stack

**Why:** Phase 2 goal is autonomous navigation. Jetson Orin Nano Super with RealSense + RPLIDAR for indoor mapping and person following.

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## Hardware Reference
| Component | Details |
|-----------|---------|
| FC | ESP32-S3 BALANCE (ESP32-S3RET6, QMI8658) |
| Motors | 2x 8" pneumatic hoverboard hub motors |
| ESC | Hoverboard ESC (EFeru FOC firmware) |
| Battery | 36V pack |
| RC | BetaFPV ELRS 2.4GHz TX + RX |
| AI Brain | Jetson Orin Nano Super + Noctua fan |
| Depth | Intel RealSense D435i |
| LIDAR | RPLIDAR A1M8 |
| Spare IMUs | BNO055, MPU6050 |

## Repo
- Gitea: https://gitea.vayrette.com/seb/saltylab-firmware
- Design doc: `projects/saltybot/SALTYLAB.md`
- Bug doc: `legacy/stm32/USB_CDC_BUG.md` (archived — STM32 era)