Project 33

Wiring Reference

Pin assignments are aligned with the current firmware constants in Firmware/Rocket/src/main.cpp and Firmware/Launcher/src/main.cpp.

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Rocket Flight Computer (ESP32 DevKit V1)

Servo Connections

| Function | GPIO Pin | Servo Position | |—————-|———-|—————-| | Left Canard | 26 | Left side | | Right Canard | 25 | Right side | | Up Canard | 27 | Top | | Down Canard | 14 | Bottom | | Ignition Servo | 5 | Motor bay |

Servo Center Calibration

| Servo | Center Angle | Max Deflection | |——-|————–|—————-| | Left | 115° | ±12° | | Right | 80° | ±12° | | Up | 80° | ±12° | | Down | 115° | ±12° |

Fin Deployment Output

| Function | GPIO Pin | Notes | |——————–|———-|———————————————-| | Fin Deploy Trigger | 33 | One-shot esp_timer output; safe LOW at boot |

The deploy output is latched HIGH by the hardware-timer ISR in Firmware/Rocket/src/deploy_isr.cpp when boost egress is detected while armed. It must stay on its own pin — it previously shared GPIO 5 with the ignition servo, which corrupted the servo PWM signal on deploy.

I2C Bus (MPU6050)

| Signal | GPIO Pin | |——–|———-| | SDA | 21 | | SCL | 22 |

UART to Launcher

| Signal | GPIO Pin | Baud Rate | |——–|———-|———–| | TX2 | 17 | 115200 | | RX2 | 16 | 115200 |

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Launcher Ground Station (ESP32 DevKit V1)

I2C Bus (QMC5883L, BMP180)

| Signal | GPIO Pin | |——–|———-| | SDA | 21 | | SCL | 22 |

I2C Device Addresses

| Device | Address | |———–|———| | QMC5883L | 0x0D | | BMP180 | 0x77 |

GPS Module (Serial1)

| Signal | GPIO Pin | Baud Rate | |——–|———-|———–| | RX1 | 4 | 9600 |

GPS TX connects to the launcher ESP32 RX1 input on GPIO 4. The firmware ignores GPS TX by passing -1 for the ESP32 transmit pin.

UART to Rocket (Serial2)

| Signal | GPIO Pin | Baud Rate | |——–|———-|———–| | TX2 | 17 | 115200 | | RX2 | 16 | 115200 |

Control Switches & Indicators

| Function | GPIO Pin | Type | Notes | |—————-|———-|——————–|—————————| | Arm Switch | 5 | Toggle Switch | INPUT_PULLUP, active LOW | | Launch Button | 18 | Momentary (N.O.) | INPUT_PULLUP, active LOW | | Status LED | 23 | LED | HIGH = on | | Buzzer | 2 | Active Buzzer | LOW-trigger | | Ignition Servo | 19 | SG90 Micro Servo | Launcher-side interlock |

WiFi Configuration

Launcher AP credentials are read from Firmware/Launcher/src/wifi_config.h. Create it by copying Firmware/Launcher/src/wifi_config.h.example, then set the local bench SSID and password before building Launcher firmware. The local header is ignored by git.

Parameter	Value
Mode	SoftAP (Access Point)
SSID	WIFI_AP_SSID
Password	WIFI_AP_PASSWORD
IP Address	192.168.4.1
UDP Port	4444

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Dashboard (Python)

Connects to the launcher’s WiFi AP and communicates with the launcher over UDP.

Parameter	Value
Listen IP	0.0.0.0
Listen Port	4444
Launcher IP	192.168.4.1

Link Layers

| Link | Transport | Purpose | |——|———–|———| | Dashboard -> Launcher | UDP/4444 over WiFi | Commands and PID tuning | | Launcher -> Dashboard | UDP/4444 over WiFi | Telemetry relay, environment data, fusion status | | Launcher <-> Rocket | UART2, 115200 baud | Rocket arming, ignition command, rocket telemetry |

Dashboard UDP Protocol

The generated protocol reference is PROTOCOL.md. | Direction | Format | Example | |———–|——–|———| | Launcher -> Dashboard | T,<launcher_ms>,<roll>,<rate>,<output> | T,1234,5.2,-3.1,4 | | Launcher -> Dashboard | STATUS:<state>,<Kp>,<Kd>,<skew> | STATUS:FLIGHT,0.5,0.2,1.3 | | Launcher -> Dashboard | ENV,<lat>,<lon>,<alt>,<gps_state> | ENV,34.1467,-118.3885,200.5,2 or ENV,0.000000,0.000000,nan,1 | | Launcher -> Dashboard | CMD_REJECT:<reason> / ABORT:<reason> | CMD_REJECT:ignite_not_armed | | Launcher -> Dashboard | [FUSION] Hdg: <deg> \| Pitch: <deg> | [FUSION] Hdg: 104.5 \| Pitch: +02.1 | | Dashboard -> Launcher | HELLO,<token> | HELLO,<DASHBOARD_AUTH_TOKEN> | | Dashboard -> Launcher | PID,<Kp>,<Kd> | PID,0.8,0.3 | | Dashboard -> Launcher | launch | launch | | Dashboard -> Launcher | calibrate | calibrate | | Dashboard -> Launcher | dumplog | dumplog |

<launcher_ms> is the launcher’s millis() when it relays the rocket’s DATA line, not the rocket’s sample time; only LOG rows carry the rocket clock. In ENV, latitude and longitude are 0.0 placeholders unless gps_state is 2, and altitude is nan when the barometer is unavailable. Missing is not zero.

Rocket UART Protocol

| Direction | Format | Example | |———–|——–|———| | Rocket -> Launcher | READY | READY | | Rocket -> Launcher | IGNITED | IGNITED | | Rocket -> Launcher | DATA,<ax>,<ay>,<az>,<roll>,<rate>,<output>,<state>,<Kp>,<Kd>,<skew> | DATA,0.02,0.10,9.78,5.2,-3.1,4,FLIGHT,0.50,0.20,1.3 | | Launcher -> Rocket | ARM | ARM | | Launcher -> Rocket | IGNITE | IGNITE | | Launcher -> Rocket | CALIBRATE | CALIBRATE | | Launcher -> Rocket | PID,<Kp>,<Kd> | PID,0.8,0.3 | | Launcher -> Rocket | DUMPLOG | DUMPLOG | | Rocket -> Launcher | LOG_START,<count> / LOG,... / LOG_END | LOG_START,240 | | Rocket -> Launcher | CMD_REJECT:<reason> | CMD_REJECT:ignite_fins_not_deployed |

GPS State Codes

| Code | Meaning | |——|———| | 0 | No NMEA data received | | 1 | NMEA data received, no valid fix yet | | 2 | Valid GPS fix acquired |

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