mcp3kadc(4) - NetBSD Manual Pages

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MCP3KADC(4)             NetBSD Kernel Interfaces Manual            MCP3KADC(4)


NAME

     mcp3kadc -- Microchip 3x0x SAR analog to digital converter


SYNOPSIS

     mcp3kadc* at spi? slave ? flags N


DESCRIPTION

     The mcp3kadc driver reports the current voltage on the chip's ADC chan-
     nels through the envsys(4) API.  The driver calculates these values
     according to the currently selected reference voltage (Vref).  It can be
     changed through the sysctl(8) node hw.mcp3kadc0.vref.

     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    Input Channels    flags
           MCP3001        10 bits       1                 0
           MCP3002        10 bits       2                 1
           MCP3004        10 bits       4                 2
           MCP3008        10 bits       8                 3
           MCP3201        12 bits       1                 4
           MCP3202        12 bits       2                 5
           MCP3204        12 bits       4                 6
           MCP3208        12 bits       8                 7
           MCP3301        13 bits       1                 8
           MCP3302        13 bits       4                 9
           MCP3304        13 bits       8                 10


SYSCTL VARIABLES

     The following sysctl(3) variables are provided:

     hw.mcp3kadc0.vref
             Defines the reference voltage on the chip's Vref pin in milli-
             volts (mV).  It defaults to the ADC's maximum output value + 1 in
             millivolts (e.g., 4096 for a 12-bit ADC).


SEE ALSO

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


HISTORY

     The mcp3kadc driver first appeared in NetBSD 8.0.


AUTHORS

     The mcp3kadc driver was written by Frank Wille.

NetBSD 8.2                      August 18, 2015                     NetBSD 8.2