Strip Down Guide for BenQ 28" VA Monitor GC2870H

MadScientist

@bachoo786 The sensor should have three pins: VCC, GND and signal out. You connect them the same way you connect a PIR sensor and it should also work with the same MM module MMM-PIR-Sensor.

yep_DD

Hi @bachoo786

thank you so much. As @MadScientist pointed out the three pins are connected directly to the Raspberry. For evaluating the state I use a small http server (see below). The important parts are where the you can find anything with

monitorStatus

If you want I can reduce the code to what is important for you. This is the complete server which allows control of

ARD Livestream
ARD Tagesschau
Lowering / Increasing volume
Radar Sensor (just the last couple lines of code (search for: GPIO.add_event_detect)
Powerin On / Off Monitor by http Request (used if no one is at home / and at night)

For me the radar sensor is just a backup. I use the power control mainly like this:

If someone is at home and it is between sunrise / sunset, turn on the monitor(1)
If someone is at home but it is night and all lights are off, turn off the monitor(1)
If someone is in front of the monitor turn it on by radar

(1) is done via FHEM (a home automation running on another raspberry, it calls my mirror like this: 10.0.1.49/on (monitor on) 10.0.1.49/off (monitor off) 10.0.1.49/up or /down (for volume) and so on.

#!/usr/bin/python3 -u
host_name = '10.0.1.49'  # Change this to your Raspberry Pi IP address
host_port = 8000
proc = ''
monitorstatus = 'unknown'

import RPi.GPIO as GPIO
from pathlib import Path
import os
import subprocess
import signal
from subprocess import call
from time import sleep
from http.server import BaseHTTPRequestHandler, HTTPServer


SENSOR_PIN = 24

GPIO.setmode(GPIO.BCM)  
GPIO.setup(SENSOR_PIN, GPIO.IN) 

class MyServer(BaseHTTPRequestHandler):

    def monitor_on(channel): #define initial status of Monitor
        if monitorstatus!="on":
            status='Monitor on by Radar Sensor'
            #monitorstatus='on'
            subprocess.Popen(["/usr/bin/vcgencmd", "display_power", "1"], preexec_fn=os.setsid)

    def do_HEAD(self):
        self.send_response(200)
        self.send_header('Content-type', 'text/html')
        self.end_headers()

    def do_GET(self):
        global proc
        global monitorstatus
        html = '''
           <html>
           <body style="width:960px; margin: 20px auto;">
           <h1>Magic Mirror Control</h1>
           <p>Current GPU temperature is {}</p>
           <p>Podcast: <a href="/play">Play</a> <a href="/stop">Stop</a></p>
           <p>ARD Livestream: <a href="/ard">Play</a> <a href="/stop">Stop</a></p>
           <p>Volume: <a href="/down">down</a> <a href="/up">up</a></p>
           <p>System: <a href="/shutdown">Shutdown</a> <a href="/restart">Restart</a></p>
           <p>Monitor: <a href="/on">On</a> <a href="/off">Off</a></p>
           <div id="podcast-status"></div>
           <script>
               document.getElementById("podcast-status").innerHTML="{}";
           </script>
           </body>
           </html>
        '''
        temp = os.popen("/opt/vc/bin/vcgencmd measure_temp").read()
        self.do_HEAD()
        status = ''
        if self.path=='/':
            #GPIO.setmode(GPIO.BCM)
            #GPIO.setwarnings(False)
            #GPIO.setup(17, GPIO.IN)
            status='nothing'
        elif self.path=='/play':
            if proc=='':
                my_file = Path("/home/pi/MagicMirror/video.mp4")
                if my_file.is_file():
                    statinfo = os.stat('/home/pi/MagicMirror/video.mp4')
                    if statinfo.st_size > 0:
                        proc = subprocess.Popen(["omxplayer", "-o", "alsa:hw:ALSA", "--no-osd", "/home/pi/MagicMirror/video.mp4"], preexec_fn=os.setsid)
                        status='Playing Podcast'
                    else:
                        proc = subprocess.Popen(["omxplayer", "-o", "alsa:hw:ALSA", "--no-osd", "/home/pi/MagicMirror/Loading.mp4"], preexec_fn=os.setsid)
                        status='Not yet available'
                else:
                    proc = subprocess.Popen(["omxplayer", "-o", "alsa:hw:ALSA", "--no-osd", "/home/pi/MagicMirror/Loading.mp4"], preexec_fn=os.setsid)
                    status='Not yet available'
            else:
                status='Stopping Podcast'
                os.killpg(os.getpgid(proc.pid), signal.SIGTERM)
                proc=''
        elif self.path=='/ard':
            if proc=='':
                proc = subprocess.Popen(["livestreamer", "hlsvariant://daserste_live-lh.akamaihd.net/i/daserste_de@91204/master.m3u8", "best", "-vnp", "omxplayer -o alsa:hw:ALSA --no-osd --timeout 20"], preexec_fn=os.setsid)
                status='Playing ARD Livestream'
            else:
                status='Stopping Stream'
                os.killpg(os.getpgid(proc.pid), signal.SIGTERM)
                proc=''
        elif self.path=='/stop':
            if proc!='':
                status='Stopping Podcast'
                os.killpg(os.getpgid(proc.pid), signal.SIGTERM)
                proc=''
            else:
                status='Nothing to stop'
        elif self.path=='/shutdown':
            status='Shutdown'
            subprocess.Popen(["sudo", "shutdown", "-h", "now"], preexec_fn=os.setsid)
        elif self.path=='/restart':
            status='Restart'
            subprocess.Popen(["sudo", "reboot"], preexec_fn=os.setsid)
        elif self.path=='/down':
            status='Volume down'
            subprocess.Popen(["amixer", "set", "Master", "8%-"], preexec_fn=os.setsid)
        elif self.path=='/up':
            status='Volume up'
            subprocess.Popen(["amixer", "set", "Master", "8%+"], preexec_fn=os.setsid)
        elif self.path=='/on':
            if monitorstatus!="on": #switch on Monitor if status was off (by httpRequest NOT Radar)
                status='Monitor on'
                monitorstatus='on'
                subprocess.Popen(["/usr/bin/vcgencmd", "display_power", "1"], preexec_fn=os.setsid)
        elif self.path=='/off':
            if monitorstatus!="off": #switch off Monitor if status was on  (by httpRequest NOT Radar)
                status='Monitor off'
                monitorstatus='off'
                subprocess.Popen(["/usr/bin/vcgencmd", "display_power", "0"], preexec_fn=os.setsid)
        self.wfile.write(html.format(temp[5:], status).encode("utf-8"))


if __name__ == '__main__':
    http_server = HTTPServer((host_name, host_port), MyServer)
    print("Server Starts - %s:%s" % (host_name, host_port))

    try:
        GPIO.add_event_detect(SENSOR_PIN , GPIO.RISING, callback=MyServer.monitor_on) #detect radar sensor and enable Monitor
        http_server.serve_forever()
    except KeyboardInterrupt:
        http_server.server_close()
GPIO.cleanup()

bachoo786

@MadScientist @yep_DD Thanks for the replies. Is there anyway to limit the distance that the radar sensor senses? I have my magic mirror in the bath room and it faces the wooden door which I believe will be detecting motion through it and I don’t want that.

MadScientist

I have a sensor that allows changing the sensitivity but for me the lowest was still to much as it got triggered when somebody walked by outside my house. I am using a PIR-Sensor now.

yep_DD

@bachoo786 apparently it also depends on the quality of the sensor, I ordered a batch on ebay and got lucky with one where I have to get really close to the glass to trigger it. at first I thought I would change it, but now I am satisfied because it fits the purpose of just activating in case the mirror is off and the other power-on / off logic didn’t work (guests at home). But if I had to redesign I would not use a sensor at all as my other ways of powering the mirror seem far more integrated, e.g. I do not want to see the mirror turn on and / off as this disturbs the design.

bachoo786

@MadScientist is your pir visible near your mirror?as it wouldn’t work behind the mirror.

@yep_DD are you talking about the rcwl0516? I have read that using a low value resistor can decrease the range of detection up to 5cm. Trouble is I don’t where to connect the additional resistor and the low value of it too.

MadScientist

I have it incorporated in the frame. I drilled a 2 or 3mm hole in the front of the frame and a 8mm hole from the back which only goes half way through. The 8mm are perfect to mount the PIR sensor without the lense. The mirror only activates when you are directly in front of it and it’s hardly visible.

bachoo786

@madscientist is it possible to share a photo please?

MadScientist

View from the back:

View from the front:

PIR sensor without IR lense and the inside-8mm-hole:

bachoo786

@madscientist very well done and looks neat thanks for that

secdude

@yep_DD

What mirror thickness did you choose? 4mm or 6mm? And why?

yep_DD

@secdude I chose 4mm glas because it is already heavy enough to mount the mirror like that.

flo

@Adrien Do you have already cut the wires of the backlight? Does it work now without HDMI logo? Whats the delay?

yep_DD

@flo actually I have not, I power the monitor via my relay and my presence dedection makes me never see the logo so so far there was no need to do that

flo

@yep_DD So you would see the logo if you only rely on the PIR? Can you share a picture of the final mirror design? I really like your frame and thinking of buying one myself.

yep_DD

@flo no, the “big” Benq logo is disabled via the developer menu of the monitor. You would only see a small “HDMI1” in the lower right. Yeah, I will post a a few pics in an hour when it is a bit darker outside. Hold on :D.

yep_DD

That’d be the final result. The wire on the first picture I was just too lazy to hide. Just needs to be pushed down.

Second picture shows the news podcast as an ovelay. No unnecessary buttons, PIR sensors or anything else that’d destroy the design.

Side note: I added an automatic Wifi Setup Feature which plays a video when it isn’t connected to a WiFi network and creates a hotspot for initial setup.

@MichMich thanks for the amazing project you created. I have had some people at my home being absolutely amazed by the mirror. I always refer them to the spirit of open source and this great community.

flo

@yep_DD it looks really neat - congratulations! A little bit too big for my taste, but I like the clean design. How much does it weight? I have only a plaster wall…

yep_DD

@flo thanks, I am very happy with it. The tiles on my wall don’t look too nice so I made the mirror as big as possible to cover that. But this design can be adapted to any size. I am guessing it weighs around 10kg. I strengthened the MDF basckplate with epoxy and used these:

to mount it to the wall. Plaster shouldn’t be a problem if you use the correct dowels and instead of two hooks you can use three if needed. Also a smaller size reduces the weight even more.

I need one more person to dismount the mirror. As I don’t want to grab on the glass plate.

I mentioned it before, but this is the frame I used (Nielsen 222):

The 25mm part is attached to doubled sided tape and holds the glas. The small inset is used for 4x4mm Rivets on each corner to screw the MFD backpate on the aluminum frame. Also strengthened with epoxy and a metal plate to distribute the total force.

cubesmi

Hi @yep_DD

Congrats on your build!

I used the same monitor for my MM - thanks to your post! :-)

Tried control the power of the backlight using a relay by passing both vled wires through it. Unfortunately it does not seem to work: as soon as I cut the power and turn it back on the monitor requires a reboot (using its power button) to get the backlights on correctly. @flo suggested the monitor may disable power output to the backlight as soon as it detects the power cut.

~~I was wondering how you connected the power button to a relay? The button board is a very filigree component and I’m worried to break it.~~ Update: Just realized you are using vcgencmd display_power 0 to turn your monitor on and off. Awesome!