Zum Inhalt

HARDWARE.md - CrowPanel ESP32 E-paper 2.9" HMI Display

Complete hardware specifications for INVERTER-ESP project.

๐Ÿ“ฑ Device Overview

Product: CrowPanel ESP32 E-paper 2.9-inch HMI Display
Manufacturer: Elecrow
Product URL: https://www.elecrow.com/wiki/CrowPanel_ESP32_E-paper_2.9-inch_HMI_Display.html

๐Ÿ”ง Core Specifications

Main Controller

  • MCU: ESP32-S3-WROOM-1-N8R2
  • CPU: Xtensaยฎ dual-core 32-bit LX7 microprocessor
  • Clock Speed: Up to 240 MHz
  • SRAM: 512 KB
  • PSRAM: 2 MB (Octal SPI PSRAM)
  • Flash: 8 MB
  • ROM: 384 KB

Wireless Connectivity

  • WiFi: 802.11 b/g/n (2.4 GHz)
  • Modes: Station, SoftAP, SoftAP+Station
  • Security: WPA/WPA2/WPA3
  • Bluetooth: Bluetooth 5.0 (LE)
  • Range: Up to 100m (open space)

Display

  • Type: E-Paper (Electronic Ink Display)
  • Size: 2.9 inches (diagonal)
  • Resolution: 296ร—128 pixels
  • Color: Monochrome (Black & White)
  • Refresh Rate: 2-15 seconds (full refresh)
  • Partial Refresh: Supported (faster updates, limited area)
  • Viewing Angle: 180ยฐ (paper-like)
  • Power Consumption:
  • Active (refresh): ~30-50 mW
  • Static (no refresh): 0 mW (bistable)

Input

  • Buttons: 3ร— Tactile Push Buttons
  • Button 1: "Next" (screen navigation)
  • Button 2: "Previous" (screen navigation)
  • Button 3: "Action" (confirm/refresh)

Power Supply

  • USB-C: 5V DC input
  • Battery: Optional 3.7V Li-Po battery (connector available)
  • Charging: Built-in charging circuit
  • Power Management: Deep Sleep support

๐Ÿ”Œ Pin Mapping

E-Paper Display (SPI Interface)

Function GPIO Pin Description
MOSI GPIO 11 Master Out Slave In (Data)
MISO GPIO 13 Master In Slave Out (unused)
SCK GPIO 12 SPI Clock
CS GPIO 10 Chip Select
DC GPIO 9 Data/Command
RST GPIO 8 Reset
BUSY GPIO 7 Busy Signal (input)

Note: Check actual pinout with Elecrow documentation or test sketch.

Buttons

Button GPIO Pin Function
BTN1 GPIO 0 Next Screen / Boot
BTN2 GPIO 14 Previous Screen
BTN3 GPIO 21 Action / Refresh

Configuration: - Pull-up resistors (internal) - Active LOW (pressed = LOW)

USB-UART Bridge

  • RX: GPIO 44
  • TX: GPIO 43

Status LED (if available)

  • LED: GPIO 2 (check documentation)

๐Ÿ“ Physical Dimensions

  • Board Size: ~100mm ร— 50mm (approximate)
  • Display Active Area: 66.9mm ร— 29.1mm
  • Mounting Holes: 4ร— M3 (check datasheet)
  • Weight: ~30g

โšก Power Specifications

Operating Voltage

  • ESP32-S3: 3.0V - 3.6V (internal LDO from 5V USB)
  • E-Paper: 3.3V (from ESP32 power rail)

Current Consumption

Mode Typ. Current Notes
Deep Sleep ~10 ยตA WiFi & CPU off
Modem Sleep ~15-30 mA CPU active, WiFi off
Light Sleep ~800 ยตA WiFi off, RTC on
WiFi Active (TX) ~150-200 mA Peak during transmission
WiFi Active (RX) ~80-100 mA Receiving data
E-Paper Refresh ~30-50 mA During display update (3-5s)
Idle (no WiFi) ~30-40 mA CPU active, WiFi off

Battery Life Estimation (2000mAh Li-Po)

Scenario 1: Frequent Updates (5 min intervals) 

Wake โ†’ WiFi Connect (20s @ 150mA) โ†’ 
       Fetch Data (5s @ 100mA) โ†’ 
       Update Display (5s @ 50mA) โ†’ 
       Deep Sleep (290s @ 0.01mA)

Average: ~2-3 mAh per cycle
Battery Life: ~30-40 days

Scenario 2: Infrequent Updates (30 min intervals) 

Deep Sleep: 99% of time
Battery Life: ~180-240 days

๐Ÿ–ฅ๏ธ E-Paper Display Characteristics

Refresh Modes

Full Refresh (2-15 seconds)

  • Complete screen update
  • Black โ†’ White โ†’ Black pattern (cleaning)
  • Best contrast and clarity
  • Use for: Screen changes, first boot

Partial Refresh (<1 second)

  • Update specific regions only
  • Faster but may leave ghosting
  • Limited refresh cycles (~100)
  • Use for: Value updates, status icons

Display Lifecycle

  • Full Refresh Cycles: 1,000,000+ (no degradation)
  • Partial Refresh: ~100-1000 (may show ghosting)
  • Image Retention: Minimal (bistable technology)

Temperature Range

  • Operating: 0ยฐC to 50ยฐC (optimal: 20-25ยฐC)
  • Storage: -20ยฐC to 70ยฐC
  • Note: Refresh slower at low temperatures

๐Ÿ”ง Development Tools

Programming Interface

  • USB-C: Serial bootloader (CH340 or CP2102 UART bridge)
  • Auto-Reset: DTR/RTS hardware flow control

Debug Interface

  • Serial Monitor: 115200 baud (default)
  • JTAG: Not exposed (use USB serial logging)

IDE Support

  • Arduino IDE: ESP32 board support (v2.0.0+)
  • PlatformIO: board = esp32-s3-devkitc-1
  • ESP-IDF: v5.0+ (advanced)

๐Ÿ“ฆ Package Contents

  1. CrowPanel ESP32 E-paper 2.9" board
  2. USB-C cable (if included)
  3. Pin header (if not soldered)
  4. Quick start guide (check Elecrow website)

๐Ÿ”— External Resources

  • Product Page: https://www.elecrow.com/crowpanel-esp32-e-paper-2-9-inch-hmi-display.html
  • Wiki: https://www.elecrow.com/wiki/CrowPanel_ESP32_E-paper_2.9-inch_HMI_Display.html
  • ESP32-S3 Datasheet: https://www.espressif.com/sites/default/files/documentation/esp32-s3_datasheet_en.pdf
  • E-Paper Driver: Check wiki for GxEPD2 or Adafruit EPD examples

โš ๏ธ Limitations & Considerations

E-Paper Display

  • โŒ Slow Refresh: Not suitable for animations or video
  • โŒ Ghosting: Partial refresh may leave traces
  • โœ… Zero Power: Display persists without power
  • โœ… Sunlight Readable: Excellent outdoor visibility

WiFi

  • โŒ No 5GHz: ESP32 only supports 2.4GHz WiFi
  • โŒ Range: Limited compared to dedicated WiFi devices
  • โœ… Low Power: Deep sleep support

Memory

  • โš ๏ธ LVGL Buffer: 296ร—128ร—1bit = 4.7KB (manageable)
  • โš ๏ธ Full RGB565: 296ร—128ร—2bytes = 74KB (use if needed)
  • โœ… PSRAM: 2MB available for buffers

๐Ÿงช Testing & Validation

  1. Display Test 

    // Full refresh test
display.fillScreen(GxEPD_WHITE);
display.display();
display.fillScreen(GxEPD_BLACK);
display.display();

  2. Button Test 

    pinMode(0, INPUT_PULLUP);
if (digitalRead(0) == LOW) {
  Serial.println("Button 1 pressed");
}

  3. WiFi Test 

    WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
  delay(500);
}
Serial.println(WiFi.localIP());

  4. Power Test 

    esp_deep_sleep(60 * 1000000ULL); // 60 seconds

๐Ÿ“ž Support

Manufacturer: Elecrow
Email: support@elecrow.com
Forum: https://www.elecrow.com/forum

Last Updated: 2025-10-23
Hardware Revision: v1.0 (check your board)