---
name: "ecadc"
section: "4"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/ecadc"
---

# ecadc(4)

environmental monitoring subsystem temperature sensor

## NAME

**ecadc** – environmental monitoring subsystem temperature sensor

## SYNOPSIS

**ecadc\* at iic?**

## DESCRIPTION

The **ecadc** driver supports the PCF8591 I2C analog to digital converter that is part of the environmental monitoring subsystem found on the Sun Enterprise 250 and Sun Enterprise 450 systems. The temperature readings are made available through the [sysctl(8)](/sysctl/8.md) interface.

The driver reads up to four A/D lines configured as temperature inputs. Sensor names, type and calibration information are read from OpenFirmware.

## SEE ALSO

[iic(4)](/iic/4.md), [intro(4)](/intro/4.md), [pcfadc(4)](/pcfadc/4.md), [sensorsd(8)](/sensorsd/8.md), [sysctl(8)](/sysctl/8.md)

## HISTORY

The **ecadc** driver first appeared in OpenBSD 4.3.

## AUTHORS

The **ecadc** driver was written by Mark Kettenis ⟨*kettenis@openbsd.org*⟩ based on the [pcfadc(4)](/pcfadc/4.md) driver written by Damien Miller ⟨*djm@openbsd.org*⟩.