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1-wire

All Pigeon computers feature a single-channel 1-Wire master interface using the DS2482S-100+ chip, providing significantly more reliable operation than direct GPIO-based communication. An external MOSFET supplies additional power to the 1-Wire bus, enabling support for devices with short-term high-current demands.

By default, OWFS (1-Wire File System) is pre-installed and configured.

As an example, the following section demonstrates how to read the temperature from a DS18B20 digital thermometer. Table 1 shows the wiring connections between the Pigeon computer and a DS18B20 sensor.

Table 1. Connections

1-WIRE DS18B20 TO-92
GND GND 1
DQ DQ 2
+5V VDD 3

Note: Although the VDD connection is optional, it is recommended for longer cable runs to ensure stable operation.

ds18b20

Fig. 1. DS18B20 Pinout

To list detected devices on the 1-Wire bus, run:

$ ls /mnt/1wire/
28.1C255E0D0000  bus.0  bus.2  settings    structure  uncached
28.4A095E0D0000  bus.1  bus.3  statistics  system

In this example, two DS18B20 sensors have been detected on the 1-Wire bus.

To read the temperature from a DS18B20 sensor, use:

$ cat /mnt/1wire/28.1C255E0D0000/temperature
27.6875

1-Wire device data is accessible through the OWFS server. To access OWFS remotely, open a web browser on another computer and enter the Pigeon's IP address followed by port 2121. For example: http://192.168.1.14:2121