NAME
mcp3kadc —
Microchip 3x0x SAR analog to digital
converter
SYNOPSIS
mcp3kadc* at spi? slave ? flags N
DESCRIPTION
Themcp3kadc driver reports the current voltage on the
chip's ADC channels 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
Vrefpin in millivolts (mV). It defaults to the ADC's maximum output value + 1 in millivolts (e.g., 4096 for a 12-bit ADC).
SEE ALSO
HISTORY
The mcp3kadc driver first appeared in
NetBSD 8.0.
AUTHORS
The mcp3kadc driver was written by
Frank Wille.