Wiren Board 6: 1-Wire extension module

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Hardware

1-Wire extension module

The module contains GPIO protection, an active 1-Wire line pull-up and a current limiter at 5Vout.

Pinout

The signals are output to the O1-O3 terminals of the extension module.

Pinout:

Terminal Function
O1 5Vout
O2 1-W
O3 GND

Configuration

Configuration is set in the web interface under Configs => Hardware Modules Configuration.

In the Internal slot 1 or 2 section (depending on the slot number) select "WBE2-I-1-WIRE" and click Save.

The device is detected immediately, no reboot is required. After adding the device the output of the dmesg command will display a message i2c-gpio mod1_i2c: using pins 24 (SDA) and 25 (SCL)

Operation

1-Wire extension module

After the sensors are connected to the controller, they appear in the Devices, column 1-wire Thermometers.

Known bugs and features

ERRE21W01: Unstable operation with long line

Affected devices

WBE2-I-1-WIRE

Description

See https://support.wirenboard.com/t/problemy-s-wbe2-i-1-wire/2967 (ru)

The WBE2-I-1-WIRE module works worse on long lines than the W1-W2 ports on the Wiren Board 6.

Reasons and detailed description

Work features of the applied chip DS2484 and protection circuits are the causes. The protection circuit limits the signal fronts when the DS2484 active pullup is active. The DS2484 bus master mistakenly enables an active pullup on a long line at the time of data transfer (active low) by the sensors. The chip also has a small sampling time, which makes its operation more sensitive to the steepness of the fronts, and therefore to the length of the line.

Workarounds

Use ports W1, W2 on the Wiren Board 6 when problems occur. Apply for a warranty replacement for a new version of the module.

=Scheduled fix

No plans. WBE2-I-1WIRE is out of production, the new module WBE2-I-1WIRE-V2 is planned, which does not have this problem.