On Thu, 22 Oct 2020 19:54:44 +0000 Markus Robert Kessler wrote:

> On Thu, 22 Oct 2020 20:11:45 +0100 Dave Liquorice wrote:
>
>> On Thu, 22 Oct 2020 17:35:12 -0000 (UTC), Markus Robert Kessler wrote:
>>
>>> I start a python script via crontab every 10 minutes which reads I2C
>>> data from a BME280 sensor. This script calculates the temperature,
>>> relative humidity and relative air pressure and sends it to a
>>> webserver.
>>
>> Can't help think why you start the script every 10 mins instead of
>> having in a loop with a 10 minute sleep. If you want *exactly* 10
>> minutes between each sample one would have to code around the
>> (variable)
>> time taken for the data sampling, processing and up load but that's not
>> difficult.
>>
>>> To be on the safe side I make / made a reboot every night. From this
>>> the questioned machine didn't return, now. I see in the log that the
>>> last transmission was ok, then the reboot was started and the
>>> connection was lost. So, I doubt that the machine completely broke
>>> down. Most likely the SDCard gave up.
>>
>> So it hasn't been power cycled and/or the SD card reseated? It could
>> just be a build up of corrosion in the slot connections. Almost all
>> Rapsberry boot problems I've had have been down to the latter or a bad
>> micro SD to SD adapater.
>>
>> Not sure why you think you need to reboot if it's only running a simple
>> script. A Pi Zero here:
>>
>> pi@PiZ-StoveB:~ $ w
>>  19:37:30 up 49 days, 10:24,
>>
>> That Pi has extra hardware attached: An ENC28J60 ethernet port, ex
>> nokia LCD phone display (both on SPI buses), a rotary encoder and a PWM
>> driven solid state relay (4 GPIO's). It's talking on two 1-Wire buses
>> (2 more GPIO's) with eight or so devices across the two buses. Every
>> minute it reads all the 1-Wire devices, updates the display, logs the
>> data (over ethernet and locally), decides if the PWM drive to the SSR
>> is correct for the data it gathered and adjusts as required. The
>> display has an animated "heartbeat" symbol that shows the system is
>> alive when the PWM is off. If the PWM is on it rotates the symbol at
>> the appropiate speed. This is all under a multi threaded python script.
>> Oh almost forgot a bi-color LED that flashes green as the 1-Wire buses
>> are read or pulses red at rate determined by the PWM.
>>
>> It's also running a web server (nginx) that can produce plots of the
>> logged data on demand.
>>
>> It's also running pi-hole.
>>
>> As you can see it's doing all that and been up nearly 50 days... I've
>> never known it crash in use.
>>
>>> P.S. I'd rather prefer to use "Raspberry Zero / WLAN" only for
>>> installation, since it has only Wifi and the network there is cable
>>> based.
>>
>> Don't follow that either.  B-)  How does the WLAN help with getting an
>> ethernet connection?
>
> WLAN doesn't help at all since at that site Wifi is deactivated. So,
> replacing an RPI-A with a RPI-Zero means one has to attach an eth-to-usb
> module. Better use it just for installing a new SDCard and then put this
> card into the RPI-A.
>
> Well, some months ago I wrote here about lost SDCards during reboot on
> RPI-Zero. Every 10 or 20 reboots the card was no longer found during
> reboot and had to be put into a desktop Linux PC. Then the partitions on
> the card were found instantly and the card worked again even in a RPI-
> Zero. Whoever I asked -- no clue why.
>
> So I decided to use RPI-Zero only for testing purposes and for logging
> data I use RPI-A, RPI-B and RPI-3.
>
> So, still interested in getting infos about if or not it is possible to
> install a new SDCard in a different RPI and then just put it into the
> mentioned RPI-A and it works?
>
> Thanks again,
> best regards,
>
> Markus

Sorry, forget to mention:

Yes, I try to install Raspbian OS.

Reason for asking all this, is, that once I saw a warning saying that
installing newer Raspberry machines like "Rpi-Zero" will only be possible
by using the most recent Raspbian versions. Older ones cannot do.

So, it seems that there are indeed some differences regarding accessing
the hardware architecture, but hopefully newer OS-es -- once installed --
can serve older hardware like "RPI-A" as well.

Let's see.

Best regards,

Markus


--
Please reply to group only.
For private email please use http://www.dipl-ing-kessler.de/email.htm

--- SoupGate-Win32 v1.05