ADM1026HM(4) | Device Drivers Manual | ADM1026HM(4)

# NAME

`adm1026hm` — Analog Devices ADM1026 complete thermal system management controller

# SYNOPSIS

`adm1026hm* at iic? addr?`

# DESCRIPTION

The `adm1026hm` driver provides support for the Analog Devices ADM1026 hardware monitor. The chip possesses 8 fan speed sensors, 3 temperature sensors, and 17 voltage sensors. The number of each sensor type configured by the driver depends on the chip configuration.

The values of the sensors are made available through the envstat(8) interface.

Sensor | Units | Description
`fan` N | RPM | Fan 0–7
`internal` | C | Internal temperature
`external` N | C | External temperature 1–2
`Vbatt` | mV DC | Battery voltage
`V3.3 standby` | mV DC | 3.3V standby voltage
`V3.3 main` | mV DC | 3.3V main voltage
`V5.0` | mV DC | 5.0V supply voltage
`V+12` | mV DC | +12V supply voltage
`V-12` | mV DC | -12V supply voltage
`V3.3` N | mV DC | Analog in (3.3V reference) 0–5
`V2.5` N | mV DC | Analog in (2.5V reference) 0–3

Configurable limits for the sensors are also available via envstat(8). Initial limit values are read from the chip. Each temperature sensor has a high, therm and low limit, which are mapped to critmax, warnmax and warnmin, respectively. Voltage sensors have high (warnmax) and low (warnmin) limits. Fan sensors have a high limit mapped to warnmin, because the fan measurements are revolution intervals, so higher numbers correlate to lower fan speeds.

# SEE ALSO

iic(4), intro(4), envstat(8)

# AUTHORS

The `adm1026hm` driver was written by Julian Coleman <jcoleman@NetBSD.org>.

# BUGS

It's not possible to determine if either a sensor is not connected, or the monitored device is producing no output. Therefore, unconnected sensors will show outputs of 0.

The `adm1026hm` driver does not support interrupt output nor the built-in EEPROM.

February 16, 2026 | NetBSD 11.99