enable gpio output when boot is complete

enable gpio output when boot is complete - Printable Version

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enable gpio output when boot is complete - Wallyboy - 12-31-2020

Hi folks; Does anyone have an idea on how I might enable a GPI pin when boot up is complete. I can setup a service to enable the pin but I am not sure how to have the action taken only after the boot up process has finished.

Thanks

RE: enable gpio output when boot is complete - taichauchau - 09-09-2021

hi, I also need this function since my external power control circuit detects gpio HIGH when boot succes and goes LOW for shuting down.

RE: enable gpio output when boot is complete - Tim Curtis - 09-09-2021

Run the commands below. If they all return "1" then high likelihood that moOde has successfully completed its boot sequence and all is well.

Code:
pi@rp1:~ $ moodeutl -q "select value from cfg_system where param='wrkready'"

1

pi@rp1:~ $ pgrep -c watchdog.sh

1

pi@rp1:~ $ pgrep -c mpd

1

RE: enable gpio output when boot is complete - adrii - 09-09-2021

Hi Wallyboy

I use the following in a (longer) shell script to pause until the Moode boot has completed (it doesn't check that MPD has started)

Code:
  ...

   # wait for worker to start to ensure start flag is set to 0

   until ps -C worker.php > /dev/null; do

      sleep 2

   done

   sleep 1     # extra time allow to set flag

   until test $(moodeutl -q "select value from cfg_system where param='wrkready'") = "1"; do

      sleep 4

   done

...

If you are using a systemd service file then you can wait for a script to complete using an ExecStartPre line

Adrian.

RE: enable gpio output when boot is complete - Wallyboy - 01-05-2024

(09-09-2021, 12:17 PM)adrii Wrote: Hi Wallyboy

I use the following in a (longer) shell script to pause until the Moode boot has completed (it doesn't check that MPD has started)

Code:
... # wait for worker to start to ensure start flag is set to 0 until ps -C worker.php > /dev/null; do sleep 2 done sleep 1 # extra time allow to set flag until test $(moodeutl -q "select value from cfg_system where param='wrkready'") = "1"; do sleep 4 done ...

If you are using a systemd service file then you can wait for a script to complete using an ExecStartPre line

Adrian.

Hi folks, I'm back to this after a hiatus. I need some help from you coding experts (I am a novice at best). I understand the boot detection part, but I'm having a problem setting the GPIO pin in an sh script. Should I be using python?. I can set a GPIO pin in python, but I don't see how to execute moodutl within a python script. Any help or direction would be much appreciated.

Kent

RE: enable gpio output when boot is complete - Tim Curtis - 01-05-2024

(01-05-2024, 05:07 PM)Wallyboy Wrote:
(09-09-2021, 12:17 PM)adrii Wrote: Hi Wallyboy

I use the following in a (longer) shell script to pause until the Moode boot has completed (it doesn't check that MPD has started)

Code:
... # wait for worker to start to ensure start flag is set to 0 until ps -C worker.php > /dev/null; do sleep 2 done sleep 1 # extra time allow to set flag until test $(moodeutl -q "select value from cfg_system where param='wrkready'") = "1"; do sleep 4 done ...

If you are using a systemd service file then you can wait for a script to complete using an ExecStartPre line

Adrian.
Hi folks, I'm back to this after a hiatus. I need some help from you coding experts (I am a novice at best). I understand the boot detection part, but I'm having a problem setting the GPIO pin in an sh script. Should I be using python?. I can set a GPIO pin in python, but I don't see how to execute moodutl within a python script. Any help or direction would be much appreciated.

Kent

https://raspberrypi-aa.github.io/session2/bash.html

RE: enable gpio output when boot is complete - Wallyboy - 01-07-2024

(01-05-2024, 10:47 PM)Tim Curtis Wrote:
(01-05-2024, 05:07 PM)Wallyboy Wrote:
(09-09-2021, 12:17 PM)adrii Wrote: Hi Wallyboy

I use the following in a (longer) shell script to pause until the Moode boot has completed (it doesn't check that MPD has started)

Code:
... # wait for worker to start to ensure start flag is set to 0 until ps -C worker.php > /dev/null; do sleep 2 done sleep 1 # extra time allow to set flag until test $(moodeutl -q "select value from cfg_system where param='wrkready'") = "1"; do sleep 4 done ...

If you are using a systemd service file then you can wait for a script to complete using an ExecStartPre line

Adrian.
Hi folks, I'm back to this after a hiatus. I need some help from you coding experts (I am a novice at best). I understand the boot detection part, but I'm having a problem setting the GPIO pin in an sh script. Should I be using python?. I can set a GPIO pin in python, but I don't see how to execute moodutl within a python script. Any help or direction would be much appreciated.

Kent

https://raspberrypi-aa.github.io/session2/bash.html

Hi Tim. Thankyou for the reply. I tried writing a short script following the directions in the link. I got an unsuccessful result as you can see in the code window. I'm lost. Any suggestions?

Code:
#!/bin/bash

echo" 18" > /sys/class/gpio/export

echo "out" > /sys/class/gpio/gpio18/direction

echo "1" > /sys/class/gpio/gpio18/value

Code:
Result:...

./boot_indicator.sh

./boot_indicator.sh: line 3: echo 18: command not found

./boot_indicator.sh: line 4: /sys/class/gpio/gpio18/direction: No such file or directory

./boot_indicator.sh: line 5: /sys/class/gpio/gpio18/value: No such file or directory

RE: enable gpio output when boot is complete - Tim Curtis - 01-07-2024

change

echo" 18" to
echo "18"

RE: enable gpio output when boot is complete - Wallyboy - 01-07-2024

(01-07-2024, 08:10 PM)Wallyboy Wrote:
(01-05-2024, 10:47 PM)Tim Curtis Wrote:
(01-05-2024, 05:07 PM)Wallyboy Wrote:
(09-09-2021, 12:17 PM)adrii Wrote: Hi Wallyboy

I use the following in a (longer) shell script to pause until the Moode boot has completed (it doesn't check that MPD has started)

Code:
... # wait for worker to start to ensure start flag is set to 0 until ps -C worker.php > /dev/null; do sleep 2 done sleep 1 # extra time allow to set flag until test $(moodeutl -q "select value from cfg_system where param='wrkready'") = "1"; do sleep 4 done ...

If you are using a systemd service file then you can wait for a script to complete using an ExecStartPre line

Adrian.
Hi folks, I'm back to this after a hiatus. I need some help from you coding experts (I am a novice at best). I understand the boot detection part, but I'm having a problem setting the GPIO pin in an sh script. Should I be using python?. I can set a GPIO pin in python, but I don't see how to execute moodutl within a python script. Any help or direction would be much appreciated.

Kent

https://raspberrypi-aa.github.io/session2/bash.html

Hi Tim. Thankyou for the reply. I tried writing a short script following the directions in the link. I got an unsuccessful result as you can see in the code window. I'm lost. Any suggestions?

Code:
#!/bin/bash echo" 18" > /sys/class/gpio/export echo "out" > /sys/class/gpio/gpio18/direction echo "1" > /sys/class/gpio/gpio18/value

Code:
Result:... ./boot_indicator.sh ./boot_indicator.sh: line 3: echo 18: command not found ./boot_indicator.sh: line 4: /sys/class/gpio/gpio18/direction: No such file or directory ./boot_indicator.sh: line 5: /sys/class/gpio/gpio18/value: No such file or directory

Thanks Tim, I should have caught that. Now I get permission denied on lines 4 and 5. I assume it's because I'm not running the commands as root. Can I run them as root within a script file? Not sure how to do that.

Thanks

RE: enable gpio output when boot is complete - Nutul - 01-07-2024

(01-07-2024, 09:09 PM)Wallyboy Wrote: Can I run them as root within a script file? Not sure how to do that.

Just prepend sudo to the command; although that rings a bell... about the "echo" thing...
Maybe it's better you include the three commands in a shell script, and then invoke the script with:

sudo ./yourscript.sh

although I am not sure if that would wait for the password... maybe making "root" the script owner, and then setting its sticky flag would have better chances of running.