MCP48X1DAC(4) | Device Drivers Manual | MCP48X1DAC(4)

# NAME

`mcp48x1dac` —
Microchip 48x1 digital to analog converter

# SYNOPSIS

`mcp48x1dac* at spi? slave ? flags N`

# DESCRIPTION

The `mcp48x1dac` driver supports the MCP48x1 family of digital to analog converters. The digital values to be converted to analog signal are passed through the sysctl(8) node.

The driver reports the current voltage output on the chip's DAC channel through the envsys(4) API. It calculates these values assuming that internal 2.048V reference voltage (`Vref`) is used.

The following table shows the supported chips. The type of the chip can be selected with the flags argument in the config file.

Designation | Resolution | flags
`MCP4801` | 8 bits | 0
`MCP4811` | 10 bits | 1
`MCP4821` | 12 bits | 2

# SYSCTL VARIABLES

The following sysctl(3) variables are provided:

machdep.mcp48x1dac0.data
  Defines digital data to be converted into analog signal. This value is interpreted literally and sent to the DAC without any conversion. Refer to the chip datasheet for more information.
machdep.mcp48x1dac0.gain
  When set to 1 it enables 2x output gain on the DAC channel. The default value is 0.

# SEE ALSO

envsys(4), spi(4), sysctl(8)

MCP4801/4811/4821 8/10/12-Bit Voltage Output Digital-to-Analog Converter with Internal VREF and SPI Interface Data Sheet.

# HISTORY

The `mcp48x1dac` driver first appeared in NetBSD 7.0.

# AUTHORS

The `mcp48x1dac` driver was written by Radoslaw Kujawa.

This man page is based on mcp3kadc(4) page by Frank Wille.

# BUGS

There are bugs.

August 23, 2015 | NetBSD 9.3