How to Use 1-Wire distributor 7 - Star Bus: Examples, Pinouts, and Specs

The 1-Wire Distributor 7 - Star Bus (Manufacturer Part ID: 11166) by Esera is a specialized component designed to simplify the connection of multiple 1-Wire devices in a star topology. It enables efficient communication and power distribution across multiple devices connected to a single 1-Wire bus. This distributor is ideal for applications requiring reliable and organized 1-Wire networks, such as home automation, industrial monitoring, and sensor networks.

• Home automation systems (e.g., temperature and humidity monitoring)
• Industrial sensor networks
• Data acquisition systems
• Smart building solutions
• Prototyping and testing of 1-Wire devices

The following table outlines the key technical details of the 1-Wire Distributor 7 - Star Bus:

The 1-Wire Distributor 7 - Star Bus features screw terminal connectors for easy wiring. Below is the pin configuration for each port:

Each of the six device ports (P1 to P6) and the bus input port (BUS IN) follow the same pin configuration.

1. Power Supply: Connect a regulated DC power supply (5V to 12V) to the BUS IN port's VCC and GND terminals.
2. 1-Wire Bus Input: Connect the 1-Wire master device (e.g., a microcontroller or USB-to-1-Wire adapter) to the BUS IN port's DATA terminal.
3. Device Connections: Connect up to six 1-Wire devices to the P1 to P6 ports. Ensure that each device's GND, DATA, and VCC lines are properly connected to the corresponding terminals.
4. Check Connections: Verify all connections to ensure proper wiring and avoid short circuits.
5. Power On: Turn on the power supply and ensure the devices are communicating correctly.

• Cable Length: Minimize the total cable length to reduce signal degradation and ensure reliable communication.
• Pull-Up Resistor: Ensure a pull-up resistor (typically 4.7kΩ) is present on the 1-Wire data line, either on the master device or the distributor.
• Power Budget: Ensure the total current consumption of all connected devices does not exceed the distributor's maximum current rating (1A).
• Environmental Conditions: Operate the distributor within the specified temperature range (-20°C to +60°C) to avoid damage.

Below is an example of how to connect the 1-Wire Distributor 7 - Star Bus to an Arduino UNO and read data from a DS18B20 temperature sensor:

1. Connect the BUS IN port's DATA terminal to Arduino pin D2.
2. Connect the BUS IN port's GND and VCC terminals to Arduino GND and 5V, respectively.
3. Connect the DS18B20 sensor to one of the distributor's device ports (P1 to P6).

#include <OneWire.h>
#include <DallasTemperature.h>

// Pin connected to the 1-Wire data line
#define ONE_WIRE_BUS 2

// Initialize the OneWire and DallasTemperature libraries
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

void setup() {
  Serial.begin(9600); // Start serial communication
  sensors.begin();    // Initialize the temperature sensors
  Serial.println("1-Wire Distributor Example: DS18B20 Sensor");
}

void loop() {
  sensors.requestTemperatures(); // Request temperature readings
  float temperature = sensors.getTempCByIndex(0); // Get temperature of first sensor

  // Print the temperature to the Serial Monitor
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" °C");

  delay(1000); // Wait 1 second before the next reading
}

1. No Communication with Devices

   • Cause: Missing or incorrect pull-up resistor on the data line.
   • Solution: Ensure a 4.7kΩ pull-up resistor is connected between the DATA and VCC lines.

2. Devices Not Detected

   • Cause: Incorrect wiring or loose connections.
   • Solution: Double-check all connections and ensure proper wiring to the distributor.

3. Signal Degradation

   • Cause: Excessive cable length or poor-quality cables.
   • Solution: Use shorter, high-quality cables and minimize the total cable length.

4. Overheating

   • Cause: Exceeding the maximum current rating (1A).
   • Solution: Ensure the total current consumption of connected devices is within the distributor's limits.

Q: Can I use this distributor with a 3.3V 1-Wire master?
A: Yes, but ensure that all connected devices are compatible with 3.3V operation.

Q: How many devices can I connect to the distributor?
A: You can connect up to six devices, one per port (P1 to P6).

Q: Does the distributor provide ESD protection?
A: No, external ESD protection is recommended for environments prone to electrostatic discharge.

Q: Can I use this distributor in a parasitic power mode?
A: Yes, the distributor supports parasitic power mode, but ensure the power supply can handle the additional load.

This concludes the documentation for the 1-Wire Distributor 7 - Star Bus. For further assistance, refer to the manufacturer's datasheet or contact Esera support.