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This code is derived from software contributed to The NetBSD Foundation
by Radoslaw Kujawa.
This code is derived from software contributed to The NetBSD Foundation
by Frank Wille.
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.Dd August 23, 2015 .Dt MCP48X1DAC 4 .Os .Sh NAME .Nm mcp48x1dac .Nd Microchip 48x1 digital to analog converter .Sh SYNOPSIS .Cd "mcp48x1dac* at spi? slave ? flags N" .Sh DESCRIPTION The .Nm driver supports the MCP48x1 family of digital to analog converters. The digital values to be converted to analog signal are passed through the .Xr sysctl 8 node.
p The driver reports the current voltage output on the chip's DAC channel through the .Xr envsys 4 API. It calculates these values assuming that internal 2.048V reference voltage .Li ( Vref ) is used.
p The following table shows the supported chips. The type of the chip can be selected with the .Ar flags argument in the config file. l -column "Designation" "Resolution" "flags" -offset indent t Sy "Designation" Ta Sy "Resolution" Ta Sy "flags" t Li "MCP4801" Ta "8 bits" Ta "0" t Li "MCP4811" Ta "10 bits" Ta "1" t Li "MCP4821" Ta "12 bits" Ta "2" .El .Sh SYSCTL VARIABLES The following .Xr sysctl 3 variables are provided: l -tag -width indent t 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. t machdep.mcp48x1dac0.gain When set to 1 it enables 2x output gain on the DAC channel. The default value is 0. .El .Sh SEE ALSO .Xr envsys 4 , .Xr spi 4 , .Xr sysctl 8 .Rs .%T MCP4801/4811/4821 8/10/12-Bit Voltage Output Digital-to-Analog Converter \ with Internal VREF and SPI Interface Data Sheet .Re .Sh HISTORY The .Nm driver first appeared in .Nx 7.0 . .Sh AUTHORS .An -nosplit The .Nm driver was written by .An Radoslaw Kujawa .
p This man page is based on .Xr mcp3kadc 4 page by .An Frank Wille . .Sh BUGS There are bugs.
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