Yet annother Retroflag NESPi case with Mausberry, Softshutdown, DUO-LED, Momentary switches

caver01

@cyperghost
I see. So you are merely simulating the voltage that would go there if the switch were triggered by supplying that voltage from the GPIO. That makes sense, and definitely easier than connecting a solid state relay or transistor across both switch poles.

cyperghost

@caver01 Exactly. As the Mausberry mains provides the same ground to all connected devices I see no problem with different ground potentials also. So this should work in general. But it would be nice if you report back.

cyperghost

@caver01
I tested with a bare mausberry switch - No Rasperry connected, no LED just the power plug via micro USB.

You measure between LED(+) and GROUND Reset Pad >> 0V
Now you connect SWITCH(+) and SWITCH(-) with one cable just for a second to simulate a momentary push button
You measure between LED(+) and GROUND Reset Pad >> 2,5V
The LED(+) simualtes a GPIO output voltage + diode = 3,3V-0,7V=2,5V
Now connect LED(+) to SWITCH(-) (just 1 seconds) and measure between LED(+) and GROUND Reset Pad >> 0V

So this seems to work in general
I used a 1N4002 Diode ... This shuts against 100V and I can provide 1A through ;)
A bit overgrowen but I don't know any cheaper parts...

EDIT:
I measured voltage between the switch-pads!
These are 5,0V and if you press the power switch the GPIO will receive back-draws and may get damaged .... So use the diode to protect the Pi - I don't know any cheaper life insurance (and this is a working one)

lostless

@cyperghost @day Word of warning. I think i just burned out my GPIO by my setup and redoing my image without the GPIO script installed in a pull up mode. Even though i had a 10K resistor to lower current, the pin was not set up at that time.. GPIO on any pin is not functioning. Im rethinking hooking up in pulldown mode just to avoid this.

found out that the 3.3 volt line is not needed. if a gpio pin is set as pullup, it gives you 3.3 volts on the pin and all you have to do i ground it. i have another issues where the gpio just stopped triggering. on my other card, its triggering just fine

cyperghost

@lostless But I think you have to stick to Python. Can you post code please?

lostless

@cyperghost i will when i figure out whats wrong with my code and why it stopped working. could be something simple as permission issues.

lostless

@cyperghost @day
ok, come to find out, you don't need to feed the gpio 3V. setting it as a pullup automatically sets it to 3.3V, I guess? its working! so new image of final.
now for the scripting. i want to thank @Heyoeyo for this and helping me understand a tad bit of python. Im using pin 32 so thats been made. change the pin to whatever one you're using. The file is in the home folder called reset.py

import RPi.GPIO as GPIO
import time
import os 

# Define which pin u're using for the reset button (change this to whatever pin you use)
resetBtn = 32


# Use 'board' pin numbering (i.e. the zig-zaging numbering scheme)
GPIO.setmode(GPIO.BOARD)
# See:   https://pinout.xyz/   for the pin layout

# Set the resetBtn pin to an input and enable the pull-up resistor
GPIO.setup(resetBtn, GPIO.IN, pull_up_down = GPIO.PUD_UP)

# Define a function which will be called when your reset button is pressed
def interrupt_resetBtn(channel):

        # Print indication to console
        print "You pressed the reset button!"

        # Code for detecting/ending an
        # emulator would go here
        os.system('/home/pi/exit.sh')


# Enable reset button interrupt to trigger on a falling edge (i.e. high-to-low transition)
GPIO.add_event_detect(resetBtn, GPIO.FALLING, callback = interrupt_resetBtn, bouncetime = 1000)

# --------------------------------------------------------------------

# Now just wait forever for the user to press a button
# The sleep time doesn't really matter, make it long enough so it isn't wasting cpu cycles
while 1:
        time.sleep(5)

so this just calls for a shell script called exit.sh i made in the home folder. thanks to @meleu for this. (What would do without him?)

# Terminate any emulatorcall!
# This works just for RetroPie!
emucall="$(sed -n 4p /dev/shm/runcommand.info | tr -d '\\"' | tr '^$[]*.()|+?{}' '.' | sed 's/[^ ]*=[^ ]* //g')"
# If there's an emulator running, we need to kill it and go back to ES
if [[ -n "$emucall" ]]; then
    emupid="$(pgrep -f "$emucall" | tr '\n' ' ')"
    pkill -P "$(echo $emupid | tr ' ' ',')"
    kill "$emupid"
    wait "$emupid"
    sleep 5 # maybe it can be lesser
fi

this needs to be made executable, if you called the file exit.sh

sudo chmod +x /home/pi/exit.sh

now add to /etc/rc.local

python /home/pi/reset.py &

right before
exit 0
reboot andnow the reset can be used to exit back to es. if you want to make reset do something else, remove the

        import os
        os.system('/home/pi/exit.sh')

and put in the code you want it to do.

lostless

This is my mauseberry custom script that seems to be working. Im starting to actually understand this scripting stuff. Thanks to @meleu and @cyperghost and tad bit of me piecing this together form their scripts.
so edit the /etc/switch.sh file after installing the mauseberry driver.

#!/bin/bash

#this is the GPIO pin connected to the lead on switch labeled OUT
GPIOpin1=23

#this is the GPIO pin connected to the lead on switch labeled IN
GPIOpin2=24

echo "$GPIOpin1" > /sys/class/gpio/export
echo "in" > /sys/class/gpio/gpio$GPIOpin1/direction
echo "$GPIOpin2" > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio$GPIOpin2/direction
echo "1" > /sys/class/gpio/gpio$GPIOpin2/value
while [ 1 = 1 ]; do
power=$(cat /sys/class/gpio/gpio$GPIOpin1/value)
if [ $power = 0 ]; then
sleep 1
else

# End Emulationstation if condition of running binary is true 
# Thanks @meleu and @cyperghost for 99.9999999999999% of this
# Edited by @lostless
 

espid="$(pgrep -f "/opt/retropie/supplementary/.*/emulationstation([^.]|$)")"
# Terminate any emulatorcall!
# This works just for RetroPie!
emucall="$(sed -n 4p /dev/shm/runcommand.info | tr -d '\\"' | tr '^$[]*.()|+?{}' '.' | sed 's/[^ ]*=[^ ]* //g')"
# If there's an emulator running, we need to kill it and go back to ES
if [[ -n "$emucall" ]]; then
    emupid="$(pgrep -f "$emucall" | tr '\n' ' ')"
    pkill -P "$(echo $emupid | tr ' ' ',')"
    kill "$emupid"
    wait "$emupid"
    sleep 5 # maybe it can be lesser
fi

if [ "$espid" ]; then
   touch /tmp/es-shutdown && chown pi:pi /tmp/es-shutdown
   kill $espid
   exit
fi
# End Emulationstation if condition of running binary is true (v1.56)

sudo poweroff
fi
done

If anyone has ideas on how to improve this. Im all ears.

meleu

@lostless said in Yet annother Retroflag NESPi case with Mausberry, Softshutdown, DUO-LED, Momentary switches:

If anyone has ideas on how to improve this.

yes. Use a proper indentation! ;-)

lostless

@meleu oh forgive for my archaic organizational skill. Be kind I’m new to this. At least I got this far. Lol 😂

caver01

@lostless said in Yet annother Retroflag NESPi case with Mausberry, Softshutdown, DUO-LED, Momentary switches:

If anyone has ideas on how to improve this. Im all ears.

I highly recommend shifting this more complicated script over to a simplified python script (which uses efficient GPIO edge detection instead of a BASH sleep/wait loop) in conjunction with @meleu's shutdown service (with updated kill process code as needed).

~~This solution~~ @meleu's service idea takes everything that has been learned about killing emus and closing ES to save metadata and makes it into a generic script that runs no matter what is doing the shutdown. In other words, it is no longer tied to a "mausberry" script. Anything can call a shutdown and the service will trigger the proper kill commands. Then, with the complex stuff out of the way, your mausberry script can either revert to the original BASH script, or can be switched to python for more efficiency/less burden on the CPU. Performance gains are probably minimal.

This has a certain elegance, as it is switch-agnostic.

meleu

@lostless said in Yet annother Retroflag NESPi case with Mausberry, Softshutdown, DUO-LED, Momentary switches:

@meleu oh forgive for my archaic organizational skill. Be kind I’m new to this. At least I got this far. Lol 😂

Hey bro, no need to apologize. I'm glad if I can inspire people to code. That was just an idea for improvement, as you requested. ;-)

lostless

@meleu I was hoping the sarcasm came though. I guess with English as your second language, it gets lost in translation. I’m not apologizing and I very much appreciate you and your desire to teach peoel. You have probably taught me more than any one else here. So keep it up.

meleu

@lostless
By the way, that emulator kill script is still not as strong as I want to make it to be. If more changes come to how runcommand invoke the emulators the script can fail to kill the emu... I'll try to make it stronger and then post the solution on that thread @caver01 linked.

Cheers!

jmcfsu13

@lostless I had said before that you didnt need to add the 3v and you disagreed lol. but after you did I did research and although it is not required it is recomended. The pullup in the pie software isnt reliable according to the interwebs and to be safe you should keep your circuit how it was

lostless

@jmcfsu13
I’m learning here. Most my knowledge is trial and error with research when I get stuck. But what do you mean by unreliable? What issues have others had? All that I can think of is possibly giving the gpio a more solid 3.3 v to work with?

cyperghost

@lostless said in Yet annother Retroflag NESPi case with Mausberry, Softshutdown, DUO-LED, Momentary switches:

@jmcfsu13
I’m learning here. Most my knowledge is trial and error with research when I get stuck. But what do you mean by unreliable? What issues have others had? All that I can think of is possibly giving the gpio a more solid 3.3 v to work with?

unreliable means that the GPIO - if it is unpowered is in a floating state.
If you wait for signal on this GPIO to get high than this can be caused by radiation by your mobile, electrostatic stroke if you touch one of the Pie components....

The most relieable method (afaik) is to power the GPIO with 2.5-3.3V to get a high signal and wait for it's state changing to 0 by pressing the button ;)

lostless

@cyperghost from what I’ve experiened, GPIO is actually powered with 3.3v From inside the pi’s GPIO pin if pull up is turned on and it turns on an internal software resistor. It still needs to be pulled down to trigger the low. All that adding the other 3.3v is to lower the current though the GPIO pin as far as I can tell.

Heyoeyo

Very cool! Makes me want to get a proper case for mine.

Just to chime in on some of the questions/comments:

Pull-up resistors:

If you configure a GPIO pin as an input and only connect a button, (no internal/external pull-up resistor) then the pin will be 'floating' until the button is pressed (i.e. it doesn't have a definite value). This means you'll get erratic signals on the pin, which will probably be misinterpreted by the pi as high-to-low and low-to-high transitions. So you might end up rebooting/shutting down your pi just by waving your hand near it.
The internal pull-up should connect a resistor (internally) from the specified GPIO to 3.3v as @lostless says. It's the same as wiring your own external resistor, it's just there to save you the hassle because it's such a common thing to do. I believe the pi also has internal pull-down resistors if you feel like flipping the circuit upside down :p
I don't know anything about the reliability of the internal pull-ups, but the situation @cyperghost is describing is exactly what you'd expect from a pin without pull-ups, so if they were enabled and it stills does that, I'd agree that they're unreliable! The main benefit of an external resistor is that it's something you can see and test, so it's definitely an option worth considering.
Enabling the internal resistor and having an external resistor increases the current draw of the circuit (you're drawing current through 2 resistors in parallel instead of 1). This isn't much of an issue if you use a big enough external resistor and the benefit is that you get an added bit of redundancy in case one resistor fails.
@lostless in the reset button wiring diagram you posted (with a 10k and 1k resistor), having that 1k resistor means the pin will only drop to 0.09V instead of fully grounding (0V) when the button is pushed. That's still well within the low-voltage threshold for the pi, so it's fine to keep it, but you can safely replace it with a direct connection if you want to simplify the circuit wiring (the 10k is providing protection from shorting the 3.3v supply. Meanwhile, connecting a GPIO-input pin directly to anything between 0-3.3V is harmless)

Reset python file:

Just a minor thing, but I'd recommend moving the line:
import os
To the top of the file (with the other import commands). As is, the script is trying to import a library every time the reset button is pressed. Python might be smart enough to ignore it after the first call (I'm not familiar enough with python to know...) but it's overall just safer/cleaner to have it do this only once at the top of the script.

Mausberry custom script:
I'm not familiar with the Mausberry, so forgive me if I'm missing/misinterpreting something here!
The script you posted looks like it could be combined into the reset python script fairly easily. I'm not super familiar with bash, but the lines:

echo "$GPIOpin1" > /sys/class/gpio/export
echo "in" > /sys/class/gpio/gpio$GPIOpin1/direction
echo "$GPIOpin2" > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio$GPIOpin2/direction
echo "1" > /sys/class/gpio/gpio$GPIOpin2/value

Seem to be configuring the pins, which I would interpret (in python) as:

GPIO.setup(GPIOpin1, GPIO.IN, pull_up_down = GPIO.PUD_DOWN)
GPIO.setup(GPIOpin2, GPIO.OUT, initial=GPIO.HIGH)

It doesn't look like the bash script uses the internal resistors (though maybe it does by default?). I've included the pull-down resistor, because of what happens in the while loop afterwards. You can remove the pull_up_down = GPIO.PUD_DOWN bit if you don't need it.

Then the while loop that follows (in the bash script) appears to be checking GPIOpin1 for a low-to-high transition to trigger a safe shutdown (I guess that has to do with the Mausberry?). You can do this in python with code similar to the reset button script:

# Define a function which will be called when the shutdown button is triggered
def interrupt_shutdownBtn(channel):
        os.system('/home/pi/maus_shutdown.sh')

# Enable shutdown button (GPIOpin1) interrupt to trigger on a rising edge (i.e. low-to-high transition)
GPIO.add_event_detect(GPIOpin1, GPIO.RISING, callback = interrupt_shutdownBtn, bouncetime = 1000)

And then you'd have to make a maus_shutdown.sh script like you did with the exit.sh script, by copying the rest of that bash script into a file:

espid="$(pgrep -f "/opt/retropie/supplementary/.*/emulationstation([^.]|$)")"
# Terminate any emulatorcall!
# This works just for RetroPie!
emucall="$(sed -n 4p /dev/shm/runcommand.info | tr -d '\\"' | tr '^$[]*.()|+?{}' '.' | sed 's/[^ ]*=[^ ]* //g')"
# If there's an emulator running, we need to kill it and go back to ES
if [[ -n "$emucall" ]]; then
    emupid="$(pgrep -f "$emucall" | tr '\n' ' ')"
    pkill -P "$(echo $emupid | tr ' ' ',')"
    kill "$emupid"
    wait "$emupid"
    sleep 5 # maybe it can be lesser
fi

if [ "$espid" ]; then
   touch /tmp/es-shutdown && chown pi:pi /tmp/es-shutdown
   kill $espid
   exit
fi
# End Emulationstation if condition of running binary is true (v1.56)

sudo poweroff

In fact, the first part of this is the exit.sh followed by some extra code to close emulationstation at the end (so you could split it up and re-use the exit script if you wanted, just be careful to move the espid=... part if you do).
Anyways, you should be able to combine the python bits into the existing reset script (though I haven't tested this!). Just make sure to copy each part into the appropriate section. So for example, the pin definitions go near the top (with resetBtn = 32), GPIO.setup lines go one after another, the interrupt functions should be written one after the other and the GPIO.add_event_detect lines should be together as well.

EDIT:
Changed one of the lines to use the pull-down resistor.

lostless

@heyoeyo well that was a read. LOL. So any way, I understand the electronics of whats going on and I figured out the pin does have its own 3.3V accidentally when i unplugged the 3.3V and the reset was still working. Pulled out my meter and, there you go 3.3V. As far as false positives, The wire run i'm running is very short to pin 32. I don't think it's going to pick up much noise plus it's running it to trigger on low. Noise would have a greater change to trigger a low to high. As far as the 10k to 3.3V being gone now, I'm willing to take the very minor risk of a possible failure of the software resistor.

Now as far as moving the import os to the top. done and It works still. Thank you for starting my understanding of python. After looking at yours I was looking at other scripts on how to program the button as a dual purpose to make the reset do 2 things based on how many times pressed. Ended up using yours, but it makes sense what i'm doing now.