# Multi-Functional Controller (MFC)
[](https://github.com/espressif/esp-idf)
[](https://www.espressif.com/en/products/socs/esp32-s3)
[](https://www.kicad.org/)
[](https://en.wikipedia.org/wiki/C_(programming_language))
[](https://www.freertos.org/)
[](#project-status--roadmap)
A custom, modular remote controller and telemetry station engineered from scratch for **long-range, low-latency 2.4 GHz RC control** and **USB/Bluetooth HID gaming**.
Built around the **ESP32-S3-N16R8 (Xtensa® 32-bit LX7 dual-core @ 240 MHz)**, this project is developed in structured hardware phases—starting from a hand-wired 6×9 cm perfboard carrier core and scaling into a full desktop/console transmitter housed in a **DT-100 (190 × 137 × 59 mm)** instrument enclosure.
---
## Phase 1: Core Carrier Board Showcase (Current Build)
The current physical hardware implements the **Core MCU & RF Carrier Stage** on a 6×9 cm perfboard:
- **ESP32-S3-N16R8 Microcontroller** (socketed on female headers)
- **nRF24L01+ 2.4 GHz RF Transceiver Module** with external dipole SMA antenna
- **100 µF Electrolytic Decoupling Capacitor** (`C1`) across the 3.3V/GND radio rails to suppress TX burst voltage droop
- **Modular Male Pin Headers & Dedicated Power Rail Headers** for external display, encoder, and joystick breakout interfacing
Figure 1: Phase 1 Top View — ESP32-S3-N16R8 module, nRF24L01+ RF transceiver, 100 µF bulk decoupling capacitor, peripheral male pin headers, and dedicated power rail male headers on a 6×9 cm perfboard.
Figure 2: Phase 1 Side Profile — 2.4 GHz external dipole antenna mounted to the nRF24L01+ module and dual USB-C ports (Native USB-OTG & UART).
Figure 3: Phase 1 Underbody Bus Routing — Point-to-point solder bridges, common ground/power rails, and FSPI signal routing between the ESP32-S3-N16R8 and male breakout headers.
---
## Phase 2: Console Expansion Bill of Materials (BOM)
The project is transitioning from the bare perfboard carrier into a self-contained console transmitter. Below is the complete English technical specification for the Phase 2 hardware expansion:
| Category | Component (English Technical Name) | Original / Part Spec | Engineering Role in Controller |
| :--- | :--- | :--- | :--- |
| **Enclosure** | **DT-100 Desktop Instrument Enclosure (Black ABS)** | `DT-100` (`190 × 137 × 59 mm`) | Main desktop/handheld transmitter chassis housing the perfboard, dual gimbals, screen, and battery pack. |
| **Display** | **1.3" ST7789 IPS TFT Color LCD Module** | `240 × 240 px`, RGB SPI, 3.3V | High-contrast full-color IPS graphical dashboard replacing the benchtop monochrome OLED. |
| **Primary Input** | **2× Dual-Axis Hall-Effect Analog Joysticks** | Contactless Magnetic 2-Axis | Drift-free 4-channel analog control (Throttle, Yaw, Pitch, Roll) routed to `ADC1`. |
| **Audio Input** | **MAX4466 Electret Microphone Amplifier Module** | Adjustable Gain, `2.4V–5.5V` | Analog voice telemetry capture and real-time audio FFT spectrum visualization on `ADC1`. |
| **Storage** | **SPI MicroSD Card Reader Module** | Standard SPI (`MOSI/MISO/SCK/CS`) | Non-volatile storage for flight/drive telemetry logs, model profiles, and UI bitmap assets. |
| **Power Boost** | **MT3608 2A Adjustable DC-DC Step-Up Boost Converter** | `2V–24V` Input, up to `28V` / `2A` Out | Boosts the 3.7V Li-ion battery rail to `5V` / `12V` for auxiliary peripherals and switch LED illumination. |
| **Master Switch** | **12–24V Illuminated Waterproof Push-Button Switch** | Latching ON-OFF, White LED Ring | Master system power / RF arming switch mounted on the DT-100 front panel. |
| **Mode Switch** | **KTS-303 Mini Toggle Switch (3-Pin SPDT)** | `ON-OFF`, Panel Mount | Physical toggle switch for flight/drive mode selection or high/low rate switching. |
| **Aux Switch** | **180° Vertical Slide Switch** | `ON-OFF` Slide, Through-Hole | Sub-circuit power rail isolation / programming mode selector. |
| **Power Diode** | **1N5817 Schottky Barrier Diode** | `1A`, `20V`, `DO-41` THT | Low forward-voltage drop ($V_F \approx 0.45\text{V}$) power rail OR-ing and reverse-polarity protection. |
| **Rectifier Diode** | **1N4001 General-Purpose Silicon Diode** | `1A`, `50V`, `DO-41` THT | Reverse-current blocking and inductive flyback protection across switched loads. |
| **Switching BJT** | **2N2222 NPN Bipolar Junction Transistor** | `40V`, `600mA–800mA`, `TO-92` | Low-side transistor switch allowing 3.3V ESP32-S3 GPIOs to drive the 12V switch LED ring (via MT3608) or buzzers. |
---
## Verified Pin Mapping (Phase 1 Firmware & Bench Harness)
The master firmware (`firmware/main/mmcontroller.c`) configures a collision-free shared **SPI2_HOST** (FSPI) bus, `ADC1` analog inputs, and the hardware `pulse_cnt` quadrature decoder:
| Peripheral / Signal | GPIO | Hardware Interface | Description |
| :--- | :---: | :--- | :--- |
| **SPI Bus: MOSI** | `GPIO 11` | SPI Master Output (`SPI2_HOST`) | Shared data line for nRF24L01+, Display (`SDA`), and MicroSD |
| **SPI Bus: MISO** | `GPIO 13` | SPI Master Input (`SPI2_HOST`) | Shared data input line from nRF24L01+ and MicroSD |
| **SPI Bus: SCK (Clock)** | `GPIO 12` | SPI Master Clock (`SPI2_HOST`) | Shared clock line for nRF24L01+, Display (`CLK`), and MicroSD |
| **nRF24L01+ Chip Select (CS)** | `GPIO 14` | SPI Device Select | Dedicated radio bus enable |
| **nRF24L01+ Chip Enable (CE)** | `GPIO 21` | Digital Output | Radio TX/RX power state activation line |
| **Display Chip Select (CS)** | `GPIO 10` | SPI Device Select | Display SPI bus enable |
| **Display Data/Command (DC)** | `GPIO 9` | Digital Output | Display command vs. frame data selection |
| **Display Reset (RES)** | `GPIO 8` | Digital Output | Hardware display reset line |
| **Joystick 1 VRx (X-Axis)** | `GPIO 4` | `ADC1` Channel 3 (`12 dB` Atten) | Analog X-axis input (`0–3.3V` safe) |
| **Joystick 1 VRy (Y-Axis)** | `GPIO 5` | `ADC1` Channel 4 (`12 dB` Atten) | Analog Y-axis input (`0–3.3V` safe) |
| **Rotary Encoder CLK** | `GPIO 15` | ESP-IDF `pulse_cnt` Unit | Quadrature channel A (hardware edge counter) |
| **Rotary Encoder DT** | `GPIO 16` | ESP-IDF `pulse_cnt` Unit | Quadrature channel B (direction sensing) |
| **Rotary Encoder Switch (SW)**| `GPIO 17` | Digital Input (`PULLUP`) | Push-button (menu enter/select mode) |
### Silicon Multiplexing Notes (ESP32-S3-N16R8 vs. Classic ESP32)
1. **Octal PSRAM & Flash Reservation (`GPIO 26 – GPIO 37`):** On the **ESP32-S3-N16R8** (8 MB Octal PSRAM), `GPIO 26` through `GPIO 37` are wired internally to the Octal SPI Flash/PSRAM bus. Accessing `GPIO 26, 27, 32, 33` triggers an immediate *Guru Meditation Error / Cache Disabled Panic* on boot.
2. **Unbonded Silicon Pins (`GPIO 22 – GPIO 25`):** `GPIO 22, 23, 24, 25` do not exist on the ESP32-S3 pin multiplexing matrix.
3. **FSPI (`SPI2_HOST`) Default Matrix:** Uses native ESP32-S3 FSPI pins (`GPIO 10, 11, 12, 13`) rather than legacy 2016 ESP32 VSPI defaults (`GPIO 5, 18, 23`).
---
## Repository Structure
```text
multi-functional-controller/
├── firmware/ # ESP-IDF C99 Firmware Project (ESP32-S3)
│ ├── CMakeLists.txt # Top-level CMake project configuration
│ ├── sdkconfig # Verified ESP32-S3 target configuration
│ └── main/
│ ├── CMakeLists.txt # Component registration
│ └── mmcontroller.c # Master firmware: Shared SPI2, Display UI, nRF24L01+, PCNT, ADC1
├── hardware/ # KiCad 10 Electronic Design Automation (EDA)
│ ├── mfc-1.kicad_pro # KiCad project file
│ ├── mfc-1.kicad_sch # Phase 1 schematic design (ESP32-S3, nRF24L01+, 100uF cap)
│ └── mfc-1.kicad_pcb # Board layout & routing rules
├── images/ # High-resolution Phase 1 prototype photography
│ ├── TOP_VIEW.png # Perfboard top view (MCU, RF, 100uF cap, male pin headers)
│ ├── SIDE_VIEW_WITH_ANTENNA.png # RF antenna and profile perspective
│ └── BOTTOM_VIEW.png # Perfboard underside solder bus & power rail wiring
├── .gitignore # Clean repository filter (builds, caches, local configs)
├── LICENSE # MIT License
└── README.md # Master engineering documentation
```
---
## Getting Started: Building the Firmware
```bash
. $HOME/esp/esp-idf/export.sh
cd firmware
idf.py set-target esp32s3
idf.py build
idf.py -p /dev/ttyACM0 flash monitor
```
---
## Project Status & Roadmap
- [x] **Phase 1 Hardware (Complete):** 6×9 cm perfboard carrier assembly with ESP32-S3-N16R8, nRF24L01+ RF module, 100 µF decoupling capacitor, signal male headers, and power rail male headers.
- [x] **Phase 1 Firmware (Complete):** Shared `SPI2_HOST` bus, 5×8 UI state machine (`DRIVE VEHICLE`, `RADIO CONFIG`, `CALIBRATE`, `SYSTEM INFO`), hardware `pulse_cnt` rotary decoding, and live nRF24 channel tuning (`0–125`).
- [ ] **Phase 2 Hardware Integration (In Progress):**
- [ ] Mount system into **DT-100 (`190 × 137 × 59 mm`)** black desktop enclosure.
- [ ] Integrate **2× Dual-Axis Hall-Effect Joysticks** (`ADC1` channels `GPIO 4, 5, 6, 7`).
- [ ] Upgrade display to **1.3" ST7789 240×240 IPS TFT LCD**.
- [ ] Wire **MT3608 DC-DC Boost Converter**, **1N5817 / 1N4001 Diodes**, and **2N2222 NPN BJT** to drive the **12–24V Illuminated Push-Button Switch**, **KTS-303 Toggle Switch**, and **180° Slide Switch**.
- [ ] Integrate **MAX4466 Microphone Amplifier** and **SPI MicroSD Card Module**.
- [ ] **Phase 3 Custom PCB:** Full multi-layer PCB fabrication in KiCad 10.
---
## Author & Project Notebook
- **Author:** [Ertunç Özbay](https://github.com/ertunc-ozbay)
- **Personal Workshop & Portfolio:** [ertuncozbay.dev](https://ertuncozbay.dev)
- **Project Detail Page:** [ertuncozbay.dev/projects/multi-functional-controller.html](https://ertuncozbay.dev/projects/multi-functional-controller.html)
- **License:** [MIT License](LICENSE)