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.