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by PetrSvetr
Sat Jul 07, 2018 8:57 am
Forum: Automation, sensing and robotics
Topic: Reed Switch Anemometor
Replies: 23
Views: 5161

Re: Reed Switch Anemometor

Looks like your anemometer puts out twice as many pulses per revolution. When you manually turn it, do you feel/hear four clicks instead of two? Reed switches are pretty quiet, so you may need to use a continuity meter to detect closure. No, this is not a problem for sure. I am using EXCELLENT pigp...
by PetrSvetr
Sat Jul 07, 2018 8:12 am
Forum: Automation, sensing and robotics
Topic: Reed Switch Anemometor
Replies: 23
Views: 5161

Re: Reed Switch Anemometor

Was/were your calibration run(s) made on an absolutely windless day? Kind of. Wind was nearly not possible to observe (grass not moving). To suppress the wind influence, I was going there and back on the same straight road, you can see it in the chart provided. Your quoting the specifications in sw...
by PetrSvetr
Fri Jul 06, 2018 9:18 pm
Forum: Automation, sensing and robotics
Topic: Reed Switch Anemometor
Replies: 23
Views: 5161

Re: Reed Switch Anemometor

I am struggling (kind of) with anemometer used on meteostations WH1080 WH1090 WS0101 WH2080 (and many others brands probably). https://www.amazon.de/gp/product/B00GGM5HEA/ref=ask_ql_qh_dp_hza In the documentation they say: The cup-type anemometer measures wind speed by closing a contact as a magnet ...
by PetrSvetr
Sat Sep 30, 2017 6:28 pm
Forum: Device Tree
Topic: external watchdog on GPIO output
Replies: 34
Views: 14576

Re: external watchdog on GPIO output

nixy82 wrote:
Wed Sep 27, 2017 11:31 am
So for example we could use GPIO lines 26 for enable and 25 for watchdog timer input.
nixy82, what do you mean by "we could use GPIO lines 26 for enable" in your post?
by PetrSvetr
Sun Sep 17, 2017 8:44 am
Forum: Device Tree
Topic: external watchdog on GPIO output
Replies: 34
Views: 14576

Re: external watchdog on GPIO output

So you think the only way for me is to periodically check for kernel updates or wait for next official release of Raspbian?
by PetrSvetr
Sun Sep 17, 2017 7:44 am
Forum: Device Tree
Topic: external watchdog on GPIO output
Replies: 34
Views: 14576

Re: external watchdog on GPIO output

Maybe a silly question, but how to get informed about new kernel release for Raspbian?
I am googling for a while but not success to find any info about it
by PetrSvetr
Sat Sep 16, 2017 8:12 am
Forum: Advanced users
Topic: (Is this) The correct ways to install the watchdog package?
Replies: 46
Views: 65920

Re: Is this the correct way to install the watchdog package?

Also because of your sceptical comments here, I started to investigate the possibility to add external watchdog to the Raspberry pi.
Thanks to an excellent support from PhilE I thing we have succeeded.
You can see our findings here: external watchdog on GPIO output
by PetrSvetr
Thu Sep 14, 2017 3:17 pm
Forum: Device Tree
Topic: external watchdog on GPIO output
Replies: 34
Views: 14576

Re: external watchdog on GPIO output

You should find that /dev/watchdog1 exists, and that gpio_wdt is loaded. 5. Now run "sudo cat /dev/watchdog1", and pin 19 should start to pulse. After a minute with no further /dev/watchdog1 activity the pulsing will stop and the signal will remain high, telling the external watchdog hardware to ca...
by PetrSvetr
Thu Sep 14, 2017 12:06 pm
Forum: Device Tree
Topic: external watchdog on GPIO output
Replies: 34
Views: 14576

Re: external watchdog on GPIO output

Your myled ticks because you have attached the gpio to a timer Yes I know it, exactly how PhilE writes, it was just the way to demonstrate I am able write/compile/install/load the Device Tree Overlay properly and I can observe/measure tickles on the intended pin. We don’t intend to use it as a repl...
by PetrSvetr
Thu Sep 14, 2017 7:57 am
Forum: Device Tree
Topic: external watchdog on GPIO output
Replies: 34
Views: 14576

Re: external watchdog on GPIO output

Thank you. Just to be sure, I am not doing any stupid mistake, I have tested following: /dts-v1/; /plugin/; / { compatible = "brcm,bcm2708"; [email protected] { target = <&leds>; __overlay__ { my_led: myled { label = "MYLED"; gpios = <&gpio 19 0>; linux,default-trigger = "timer"; }; }; }; }; From my last e...
by PetrSvetr
Wed Sep 13, 2017 10:51 pm
Forum: Device Tree
Topic: external watchdog on GPIO output
Replies: 34
Views: 14576

Re: external watchdog on GPIO output

As far no success compiled following dts /dts-v1/; /plugin/; / { compatible = "brcm,bcm2708"; [email protected] { target = <&watchdog>; __overlay__ { compatible = "linux,wdt-gpio"; gpios = <&gpio 19 0>; hw_algo = "toggle"; hw_margin_ms = <500>; //Maximum time to reset watchdog circuit (milliseconds). }; };...
by PetrSvetr
Wed Sep 13, 2017 8:33 pm
Forum: Device Tree
Topic: external watchdog on GPIO output
Replies: 34
Views: 14576

Re: external watchdog on GPIO output

From my understanding of the HW watchdog function (in general) and from the Linux watchdog SW implementation: HW watchdog is an independent HW circuit/device , generally the countdown timer this countdown timer has to be reset to the initial countdown value periodically otherwise the HW reset of the...
by PetrSvetr
Wed Sep 13, 2017 1:55 pm
Forum: Device Tree
Topic: external watchdog on GPIO output
Replies: 34
Views: 14576

Re: external watchdog on GPIO output

Sorry I was not clear/specific enough. In general, watchdog "ticking" to the GPIO pin can be used for any of the EXTERNAL HW watchdog. In the example in my initial post here, the AM706 is mentioned. In our case, we are going to build a power source for the raspberry equipped by PIC microcontroler wh...
by PetrSvetr
Wed Sep 13, 2017 12:41 pm
Forum: Device Tree
Topic: external watchdog on GPIO output
Replies: 34
Views: 14576

external watchdog on GPIO output

In Linux it is generally possible to redirect kernel watchdog module ticking to GPIO (external HW watchdog) instead of the build in HW watchdog on the motherboard. See: https://www.kernel.org/doc/Documentation/devicetree/bindings/watchdog/gpio-wdt.txt https://cateee.net/lkddb/web-lkddb/GPIO_WATCHDOG...
by PetrSvetr
Mon Sep 11, 2017 5:15 pm
Forum: Device Tree
Topic: dt overlay syntax (for HAT EEPROM)
Replies: 2
Views: 2325

Re: dt overlay syntax (for HAT EEPROM)

PhilE, I have made two steps (both were successful) 1) * compiled below code as my_gpio.dtb * copied to the /boot/overlays * activated by adding "dtoverlay=my_gpio" to /boot/config.txt /dts-v1/; /plugin/; / { compatible = "brcm,bcm2708"; [email protected] { target-path = "/"; __overlay__ { power_ctrl: powe...
by PetrSvetr
Thu Sep 07, 2017 12:48 pm
Forum: Device Tree
Topic: dt overlay syntax (for HAT EEPROM)
Replies: 2
Views: 2325

dt overlay syntax (for HAT EEPROM)

Generally my aim is to solve below described tasks using dts stored in the HAT EEPROM: trigger shut-down when signal detected on GPIO input feed external watchdog by ticking on the GPIO output predictably change the state of the GPIO output to signalize clean shut down using gpio-poweroff Thanks to ...
by PetrSvetr
Sun Sep 03, 2017 8:46 am
Forum: Device Tree
Topic: how to trigger an action when input signal is detected
Replies: 7
Views: 7200

Re: how to trigger an action when input signal is detected

link to the print-screen photo didn’t work in my previous post, here is the link again
https://goo.gl/photos/Ekiy3k6jnBZZ4HbW9
by PetrSvetr
Sun Sep 03, 2017 8:43 am
Forum: Device Tree
Topic: how to trigger an action when input signal is detected
Replies: 7
Views: 7200

Re: how to trigger an action when input signal is detected

Partial success here. Generally my aim is to solve below described tasks using dts stored in the HAT EEPROM: trigger shut-down when signal detected on GPIO input feeding external watchdog by ticking on the GPIO output predictably change the state of the GPIO output to signalize clean shut down using...
by PetrSvetr
Thu Jun 08, 2017 5:07 pm
Forum: Device Tree
Topic: how to trigger an action when input signal is detected
Replies: 7
Views: 7200

Re: how to trigger an action when input signal is detected

Wow, notro... it is really high level reply. Thank you very much . In principle I understand, but it looks we have to study a lot!!!! On the other hand, I am thinking how to prepare our hardware for users so the deployment on the user side is as smooth/simple as possible.. Empty EEPROM and navigate ...
by PetrSvetr
Wed Jun 07, 2017 8:49 pm
Forum: Device Tree
Topic: how to trigger an action when input signal is detected
Replies: 7
Views: 7200

how to trigger an action when input signal is detected

We are designing power source for RPI and we would like to be compatible to the HAT description. The DT is kind of complex to us, but we are studying and trying to do our best to understand. I understand how to set the GPIO output to provide signal for external watchdog for example. https://communit...

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