[Mageia-discuss] One-Wire Home Temperature Network with Linux

[AL13N]

Op zondag 15 juli 2012 16:21:06 schreef Juergen Harms:
> On 07/15/2012 03:13 PM, Doug Lytle wrote:
> > I've just started to play with a 1 wire temperature sensor, under Mageia
> > 1. I've been following a couple of blog on how to get things setup (1 &
> > 2).
> > 
> > I've installed the digitemp software (2) via urpmi and can actually see
> > the USB dongle (DS9490R) and my temp sensor (DS18B20).
> > 
> > The problem being that when running the command digitemp_DS2490 -a -i
> > -q, it is supposed to write out it's configure file (.digitemprc) to the
> > profile directory, which for me running the command as root, should be
> > /root/.digitemprc, but it doesn't.
> > 
> > Has anybody played around with temperature sensors under Mageia? If so,
> > were you able to get it to write out the file?
> > 
> > Doug
> > 
> > (1)
> > http://bitsup.blogspot.com/2008/11/one-wire-home-temperature-network-with.
> > html
> > 
> > (2) http://www.nslu2-linux.org/wiki/HowTo/AddUSBOneWireAdapter
> > (3) http://digitemp.com
> 
> I have DS18B20 sensors running, but not on Mageia - my sensors are
> connected to an AVR microprocessors (which is controlled by a C
> programme, downloaded from my Mageia PC).
> 
> I have doubts whether it is possible to reliably operate 1-wire devices
> directly connected to a PC that is simultaneously used to do "ordinary
> stuff": the 1-wire protocol has quite strict bit-timing requirements
> (the pin on the I/O port on your PC which drives the 1-wire bus must
> create pulses with well-defined lengths and intervals), not evident to
> implement on a time-shared PC - could also have negative impact on non
> real-time applications that run on the PC. You might need to more or
> less dedicate your PC to run your 1-wire application.
> 
> In case you cannot make it work directly on Mageia, the microprocessor
> approach is certainly a valid (even better?) alternative since the
> microprocessor can print the result to a serial port and hence to a PC.
> 
> In case this approach is of interest to you, we should discuss this by
> PM (no problem to let you have my hard- and software)
> 
> Juergen

or you could make a pci-board (or usb device with it's internal clock and 
send/recv queue, so it's all nicely timed...