Digi Watchport/T temperature sensor as /dev/ttyU

[Warner Losh]

On Tue, Aug 9, 2016 at 8:10 AM, Gary Palmer <gpalmer at freebsd.org> wrote:
> On Tue, Aug 09, 2016 at 08:28:47AM -0500, Karl Denninger wrote:
>>
>> On 8/9/2016 01:36, O. Hartmann wrote:
>> > On Sun, 24 Jul 2016 13:12:35 -0600
>> > Ian Lepore <ian at freebsd.org> wrote:
>> >
>> >> On Sun, 2016-07-24 at 12:52 -0600, Warner Losh wrote:
>> >>> On Sun, Jul 24, 2016 at 12:42 PM, Kevin Oberman <rkoberman at gmail.com>
>> >>> wrote:
>> >>>> There are several different USB serial drivers. Off-hand I see
>> >>>> ubser, ubsa,
>> >>>> uchcom, ucom, ucycom, uftdi, ubgensa, umcs, umct, umoscom, uplcom,
>> >>>> usb_serial, uslcom, and uvscom. Whether any of these will support
>> >>>> the TI
>> >>>> chip, I can't say. Most have man pages, but a few, as has been
>> >>>> noted, are
>> >>>> lacking one.
>> >>> I tried to automate discovery of these things. However, the only way
>> >>> you can really know for sure about the TI chip is to read it's
>> >>> datasheet
>> >>> and compare that with extant drivers. It's actually easier than it
>> >>> sounds.
>> >>>
>> >>> I've often thought of unification of the TTY USB drivers, since they
>> >>> are
>> >>> most (but not all) based on the standard plus extra bits.
>> >>>
>> >>> Warner
>> >> To reiterate:  we do not have a driver for TI 5052 chips.
>> >>
>> >> It's not much like other usb-serial chips.  In fact it's not strictly a
>> >> usb-serial chip, it's a multifunction chip that includes a software
>> >> -controllable usb hub, 2 serial ports, gpio, an i2c bus master, an MCU
>> >> interface, a multichannel DMA controller, and apparently even has the
>> >> ability to download your own 8052-compatible microcontroller code into
>> >> the 5052 and have it take over from the built-in rom code.
>> >>
>> >> It would be reasonable enough to write a driver that initially
>> >> supported only the uart part of the chip.
>> >>
>> >> -- Ian
>> > Now, that I know that I can not use any of our plenty Digi Watchport/T sensors
>> > with FreeBSD, I'm looking for a cheap alternative of sensor, prefereably being
>> > capable of taking temperature and humidity and being accessed as easy as a
>> > serial terminal - as the Digi Watchport/T does with Linux.
>> >
>> > I still have a "resistance" changing the OS of our infrastructure to Linux due
>> > to ZFS, but the very good support of drivers with the Linux OS is tempting ...
>> > _______________________________________________
>> > freebsd-usb at freebsd.org mailing list
>> > https://lists.freebsd.org/mailman/listinfo/freebsd-usb
>> > To unsubscribe, send any mail to "freebsd-usb-unsubscribe at freebsd.org"
>>
>> Does hardware platform matter?  If not a very inexpensive alternative
>> set is found on Adafruit's site for the Raspberry Pi and FreeBSD can
>> easily talk to either some of the options directly or a cheap ($10)
>> 4-channel 12-bit analog board.  I am using this approach with the Pi2 as
>> a pool controller with multiple temperature inputs and drive (through a
>> relay board) to handle both the VFD-controlled pump motor and valves,
>> plus spa heater.
>
> If you go down that path the DS 18B20 is a digital temperature probe
> that can be tied to the GPIO pins on a PI and read from python
> quite easily.  Don't think it does humidity, but as the temp. probes
> have a hardware address you can hook multiple up to the same GPIO pin.

18B20 doesn't support humidity. The kernel also supports reading
it periodically and reporting the results via a sysctl now that we have
onewire support in the kernel. This has worked better for me than
reading them from Python...

> If you want humidity also then there is the DHT22 or DHT11, both
> of which can be tied to the PI but need a GPIO pin per sensor.  I
> haven't tried either of them personally.

Those work, but same here. I've not tried them personally.

Warner