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Diffstat (limited to 'static/netbsd/man4/am2315temp.4')
| -rw-r--r-- | static/netbsd/man4/am2315temp.4 | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/static/netbsd/man4/am2315temp.4 b/static/netbsd/man4/am2315temp.4 new file mode 100644 index 00000000..6a4c58d4 --- /dev/null +++ b/static/netbsd/man4/am2315temp.4 @@ -0,0 +1,97 @@ +.\" $NetBSD: am2315temp.4,v 1.2 2017/12/29 14:47:09 wiz Exp $ +.\" +.\" Copyright (c) 2017 Brad Spencer <brad@anduin.eldar.org> +.\" +.\" Permission to use, copy, modify, and distribute this software for any +.\" purpose with or without fee is hereby granted, provided that the above +.\" copyright notice and this permission notice appear in all copies. +.\" +.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +.\" +.Dd December 28, 2017 +.Dt AM2315TEMP 4 +.Os +.Sh NAME +.Nm am2315temp +.Nd Driver for Aosong AM2315 sensor chip via I2C bus +.Sh SYNOPSIS +.Cd "am2315temp* at iic? addr 0x5c" +.Sh DESCRIPTION +The +.Nm +driver provides measurements from the AM2315 humidity/temperature +sensors via the +.Xr envsys 4 +framework. +The +.Nm +.Ar addr +argument selects the address at the +.Xr iic 4 +bus. +The AM2315 has limits on how often the measurements can be read. +Adjustments to the number of times to take reading before considering +it valid, and the number of ticks to wait between readings can be +changed through +.Xr sysctl 8 +nodes. +.Pp +There are other oddities about the AM2315 that should be mentioned. +The datasheet says that the device should read no more often then +every 2 seconds, further, it also implies that a measurement is not +performed until the device is 1) awake 2) has been asked for a +measurement. +From observation, it has been noted that it is possible +to ask for measurements more often than every 2 seconds, and actually +get something that looks to be valid. +It may, in fact, be valid, but +it has also been noted that the measurements do not appear to change. +This implies that a measurement was done, and then returned time and +time again. +It has also been noticed that if measurements are taken +very close to every 2 seconds, that sometimes the device will return a +I2C error on a read. +If this happens a lot, increase hw.am2315temp0.readticks a bit. +.Sh SYSCTL VARIABLES +The following +.Xr sysctl 3 +variables are provided: +.Bl -tag -width indent +.It hw.am2315temp0.readcount +The number of times to take a reading before considering it valid. +This defaults to 2. +.It hw.am2315temp0.readticks +The number of ticks to wait in between readings. +The default is 100. +.It hw.am2315temp0.debug +If the driver is compiled with +.Dv AM2315_DEBUG , +this node will appear and can be used to set the debugging level. +.El +.Sh SEE ALSO +.Xr envsys 4 , +.Xr iic 4 , +.Xr envstat 8 , +.Xr sysctl 8 +.Sh HISTORY +The +.Nm +driver first appeared in +.Nx 8.0 . +.Sh AUTHORS +.An -nosplit +The +.Nm +driver was written by +.An Brad Spencer Aq Mt brad@anduin.eldar.org . +.Sh BUGS +The device does not appear to work with the +.Xr gpioiic 4 +bitbang controller. +When tried, reads would not error, but no data was returned. |
