Hardware Setup
Microcontroller Optionsβ
ESP32-C3 Super Mini (Current)β
The ESP32-C3 Super Mini is a compact development board with excellent performance for this project.
XIAO ESP32-C6 (Recommended Upgrade)β
The XIAO ESP32-C6 offers significant improvements:
- 13-14% better battery life due to improved power efficiency
- WiFi 6 support for enhanced connectivity
- Identical pinout - plug-and-play upgrade from ESP32-C3
- Enhanced performance with more memory and faster processing
π‘ Both boards use the same wiring and code - choose based on availability and requirements.
ESP32-C3 Super Mini Pin Layoutβ
Pin Layoutβ
The ESP32-C3 Super Mini is a compact development board with the following pin assignments:
General Purpose Pinsβ
| Pin | GPIO | Function | Notes |
|---|---|---|---|
| A0 | 0 | Analog/Digital | |
| A1 | 1 | Analog/Digital | |
| A2 | 2 | Digital | Used for E-Paper BUSY |
| A3 | 3 | Digital | Used for E-Paper CS |
| A4 | 4 | Digital | User Button (shares with SCK) |
| A5 | 5 | Digital | Shares with MISO |
| GPIO10 | 10 | Digital | General purpose |
Communication Pinsβ
| Pin | GPIO | Function | Notes |
|---|---|---|---|
| SCK | 4 | SPI Clock | Shared with A4/User Button |
| MISO | 5 | SPI MISO | Shared with A5 |
| MOSI | 6 | SPI MOSI | Used for E-Paper SDI |
| SS | 7 | SPI Chip Select | General purpose |
| SDA | 8 | I2C Data | Used for E-Paper RES |
| SCL | 9 | I2C Clock | Used for E-Paper DC |
| RX | 20 | UART Receive | Serial communication |
| TX | 21 | UART Transmit | Serial communication |
E-Paper Display Wiringβ
Required Connectionsβ
The e-paper display requires 6 GPIO pins + 3.3V + Ground (total 8 pins):
| E-Paper Pin | ESP32-C3 Pin | GPIO | Function |
|---|---|---|---|
| BUSY | A2 | 2 | Busy signal |
| CS | A3 | 3 | Chip Select |
| SCK | SCK | 4 | SPI Clock |
| SDI | MOSI | 6 | SPI Data In |
| RES | SDA | 8 | Reset |
| DC | SCL | 9 | Data/Command |
| 3.3V | 3.3V | - | Power supply |
| GND | GND | - | Ground |
Wiring Diagramβ
ESP32-C3 Super Mini E-Paper Display
βββββββββββββββββββ βββββββββββββββββββ
β 3.3V βββββββΌββββββββββΌββ 3.3V β
β GND βββββββΌββββββββββΌββ GND β
β GPIO 2 βββββββΌββββββββββΌββ BUSY β
β GPIO 3 βββββββΌββββββββββΌββ CS β
β GPIO 4 βββββββΌββββββββββΌββ SCK β
β GPIO 6 βββββββΌββββββββββΌββ SDI β
β GPIO 8 βββββββΌββββββββββΌββ RES β
β GPIO 9 βββββββΌββββββββββΌββ DC β
βββββββββββββββββββ βββββββββββββββββββ
Pin Conflictsβ
β οΈ Important Pin Sharing Notes:
- GPIO 4: Shared between SPI SCK and User Button
- GPIO 5: Shared between SPI MISO and A5
- GPIO 8: Shared between I2C SDA and E-Paper RES
- GPIO 9: Shared between I2C SCL and E-Paper DC
Power Supplyβ
Power Optionsβ
- USB-C: 5V input, regulated to 3.3V on-board
- Battery: 3.7V LiPo battery (JST connector if available)
- External 3.3V: Direct 3.3V supply to 3.3V pin
Power Consumptionβ
- Active mode: ~80-120mA (WiFi + display update)
- Deep sleep: ~10-50ΞΌA (depending on configuration)
- Estimated battery life:
- 2000mAh battery: 2-4 weeks (5-minute update intervals)
- 1000mAh battery: 1-2 weeks (5-minute update intervals)
Assembly Tipsβ
Solderingβ
- Use flux for clean solder joints
- Start with power connections (3.3V, GND)
- Double-check polarity before powering on
- Test continuity with multimeter
Enclosure Considerationsβ
- Ensure antenna clearance for WiFi
- Provide access to USB-C for programming
- Consider heat dissipation during operation
- Protect against moisture if used outdoors
Testingβ
- Power test: Verify 3.3V supply
- SPI test: Check e-paper display communication
- WiFi test: Verify network connectivity
- Full system test: Run complete firmware
Troubleshooting Hardware Issuesβ
Display Not Workingβ
- Check all 8 connections (6 GPIO + power)
- Verify 3.3V power supply stability
- Ensure proper SPI timing (check SCK signal)
WiFi Connection Issuesβ
- Check antenna clearance
- Verify power supply stability during transmission
- Ensure proper grounding
Power Issuesβ
- Measure actual power consumption vs. expected
- Check for shorts or incorrect wiring
- Verify deep sleep functionality