eletechsup ES32G15 WIFI RS485 Remote IO Control Board

1. Introduction

The ES32G15 is a versatile multi-function expansion board specifically designed for the ESP32-DevKitC. Developed by eletechsup, this board integrates a comprehensive array of analog and digital input/output circuits, including NTC temperature acquisition, current and voltage I/O, NPN digital inputs, and robust relay outputs. It serves as an ideal platform for developers working on industrial control, automation, and data acquisition projects with the ESP32. To streamline development, the pin mapping for each port is clearly printed on the reverse side of the PCB.

Note: The ES32G15 cannot operate independently. It requires a 38PIN ESP32-DevKitC board (not included) for full functionality. Users without an ESP32 board should acquire one separately or purchase a compatible kit.

2. Specifications

2.1 General Specifications

• Working Voltage: Wide voltage DC 12-28V
• Working Current:
  • Standby: 15mA
  • 1 Relay Open: 50mA
  • 2 Relays Open: 85mA
  • 3 Relays Open: 120mA
  • 4 Relays Open: 155mA
• Dimensions (Only Board): 121mm x 72mm x 19mm
• Weight:
  • Only Board: 95g
  • With Shell: 186g

2.2 Onboard Resources

The ES32G15 board provides the following input/output capabilities:

• Analog Outputs (AO):
  • 2 Channels 0/4-20mA Current Output
  • 2 Channels 0-5V/10V Voltage Output
• Analog Inputs (AI):
  • 2 Channels 0/4-20mA Current Input
  • 2 Channels 0-5V/10V Voltage Input
• Temperature Inputs: 4 Channels 10K NTC Input (supports any B value thermistor)
• Digital Inputs (DI): 4 Channels NPN Digital Input
• Digital Outputs (DO): 4 Channels 10A Relay Output
• Communication: 1 Channel RS485 Port
• General Purpose: 5 Channels Free Port (directly derived from ESP32 GPIOs)

3. Components Overview

The ES32G15 board is designed for easy integration with the ESP32-DevKitC. Key components and interfaces include:

• ESP32-DevKitC Header: Central socket for plugging in a 38PIN ESP32 board.
• Power Interface: Screw terminals for DC 12-28V power input.
• RS485 Interface: Screw terminals for RS485 communication.
• Analog I/O Terminals: Screw terminals for voltage and current inputs and outputs.
• NTC Input Terminals: Screw terminals for connecting 10K NTC thermistors.
• NPN Digital Input Terminals: Screw terminals for NPN digital signals.
• Relay Output Terminals: Screw terminals for connecting loads to the 4 onboard relays.
• Free Port Terminals: Screw terminals providing direct access to additional ESP32 GPIOs.
• SW1 DIP Switch: A 4-position DIP switch used to configure multiplexed analog output types.
• 5V/3.3V Power Output: Pin headers for auxiliary power supply.

4. Setup Guide

4.1 Prerequisites

• eletechsup ES32G15 Expansion Board
• 38PIN ESP32-DevKitC Board (compatible with 22.5mm or 25.4mm width)
• DC 12-28V Power Supply
• Appropriate wiring and tools

4.2 ESP32 Board Installation

1. Carefully align the 38PIN ESP32-DevKitC board with the header pins on the ES32G15 expansion board.
2. Gently press the ESP32 board into the header until it is securely seated. Ensure all pins are correctly inserted and there are no bent pins.

4.3 Power Connection

1. Connect your DC 12-28V power supply to the 'Power Supply DC 12-28V' screw terminals on the ES32G15 board.
2. Ensure correct polarity: connect the positive (+) terminal of the power supply to the 'V+' terminal on the board, and the negative (-) terminal to the 'GND' terminal.
3. Verify the power supply voltage is within the specified range (12-28V DC) before applying power.

4.4 Multiplexed Output Configuration (SW1 DIP Switch)

The ES32G15 features multiplexed analog output ports (Vo1/Io1 and Vo2/Io2). This means that for each pair, you must select either voltage output (Vo) or current output (Io) using the SW1 DIP switch. Only one type can be enabled per pair.

The SW1 DIP switch has four positions, controlling the selection as follows:

• SW1-1: Enables Voltage Output for Channel 1 (Vo1).
• SW1-2: Enables Current Output for Channel 1 (Io1).
• SW1-3: Enables Voltage Output for Channel 2 (Vo2).
• SW1-4: Enables Current Output for Channel 2 (Io2).

Important: For Vo1/Io1, ensure only SW1-1 or SW1-2 is ON at any given time. Similarly, for Vo2/Io2, ensure only SW1-3 or SW1-4 is ON. Having both switches ON for the same channel (e.g., SW1-1 and SW1-2) or both OFF will result in incorrect or no output.

5. Operating Instructions

5.1 Pin Mapping

The following table details the mapping between the ES32G15 expansion board ports and the corresponding pins on the 38PIN ESP32-DevKitC. This information is crucial for programming your ESP32.

5.2 Wiring Diagram Example

The following diagram provides an example of how various components can be wired to the ES32G15 board. Always refer to the specific requirements of your sensors and actuators.

5.3 Programming the ESP32

The ES32G15 is an expansion board, and its functionality is controlled by the ESP32-DevKitC. You will need to program the ESP32 using an appropriate development environment (e.g., Arduino IDE with ESP32 core, ESP-IDF).

• Basic Arduino code for testing the hardware is typically provided by the manufacturer.
• For specific applications and advanced functionalities, you are expected to develop your own custom code.
• Familiarize yourself with ESP32 programming concepts, including GPIO control, ADC/DAC usage, serial communication (RS485), and NTC thermistor reading algorithms.

6. Maintenance

• Cleaning: Keep the board clean and free from dust, dirt, and debris. Use a soft, dry brush or compressed air for cleaning. Avoid using liquids or solvents.
• Moisture Protection: Protect the board from moisture and humidity. Operate it in a dry environment.
• Ventilation: If the board is enclosed, ensure adequate ventilation to prevent overheating, especially when relays are frequently switching.
• Connection Checks: Periodically inspect all screw terminal connections to ensure they are tight and secure. Loose connections can lead to intermittent operation or damage.
• Environmental Conditions: Avoid exposing the board to extreme temperatures, direct sunlight, or strong electromagnetic fields.
• Static Discharge: Handle the board with care, especially in dry environments, to prevent damage from electrostatic discharge (ESD). Use anti-static precautions if possible.

7. Troubleshooting

• Board Not Powering On:
  • Verify the DC 12-28V power supply is connected correctly and providing the specified voltage.
  • Check power supply polarity (+ to V+, - to GND).
  • Ensure the ESP32 board is properly seated in its header.
• ESP32 Not Detected or Programming Issues:
  • Confirm the ESP32-DevKitC board is fully inserted and making good contact.
  • Check your ESP32 development environment settings (board selection, COM port).
• Analog Outputs (Vo/Io) Not Working or Incorrect:
  • Review the SW1 DIP switch settings (Section 4.4) to ensure the correct output type (Voltage or Current) is enabled for each channel.
  • Verify your ESP32 code is writing to the correct GPIOs (IO25/IO26) for analog output.
  • Check external wiring and load impedance.
• Analog Inputs (Vi/Ii) Reading Incorrectly:
  • Ensure input signals are within the specified ranges (0-5V/10V or 0/4-20mA).
  • Verify your ESP32 code is reading from the correct ADC pins (IO36/IO39 for voltage, IO34/IO35 for current).
  • Check for proper sensor wiring and calibration.
• NTC Temperature Readings Are Off:
  • Confirm you are using 10K NTC thermistors.
  • Verify the NTC thermistors are correctly wired to T1-T4.
  • Check your ESP32 code's NTC resistance-to-temperature conversion algorithm.
• Digital Inputs (IN) Not Responding:
  • Ensure NPN digital signals are correctly wired to IN1-IN4.
  • Verify your ESP32 code is configured to read from the corresponding GPIOs (IO19/IO18/IO5/IO17).
• Relays (CH) Not Activating:
  • Check the power supply to the board.
  • Verify your ESP32 code is sending the correct control signals to the relay GPIOs (IO12/IO13/IO21/IO23).
  • Ensure the external load connected to the relay is within the 10A rating and wired correctly.
• RS485 Communication Failure:
  • Check RS485 wiring (A to A, B to B).
  • Verify baud rate and communication settings in your ESP32 code match the connected device.
  • Consider adding external termination resistors if experiencing signal integrity issues over long distances (though not explicitly required by the board itself).

8. User Tips

• Development Focus: This board is primarily designed for developers. While basic Arduino code is provided for hardware testing, advanced functionalities and specific application requirements will necessitate custom programming. A solid understanding of ESP32 programming and the Arduino IDE (or ESP-IDF) is highly recommended.
• Wiring Verification: Always double-check all wiring connections, especially power inputs and the SW1 DIP switch settings for multiplexed outputs, before applying power to the board. Incorrect wiring can lead to component damage.
• Documentation: Keep this manual and any provided code examples handy during development. Refer to the pin mapping frequently to ensure correct GPIO assignments in your software.

9. Warranty and Support

This product is manufactured and supplied by eletechsup. For technical support beyond the scope of this documentation and the provided basic hardware testing code, users are encouraged to consult the extensive resources available for ESP32 development, including official Espressif documentation, community forums, and online tutorials. The manufacturer provides the hardware and basic testing examples but does not offer extensive custom code development or project-specific technical assistance.

Please refer to the seller's terms and conditions for any specific warranty information.