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MG-811 — Parallax Forums

MG-811

Good day,
any body can help me with MG811 sensor,
i connect it in reverse on arduino then not it is in reverse direction and i correct it,
and i determine the + side by multimeter with 1M ohm internal resistor,
now what i should do to get it to work or it damaged?
how i confirm it damage if you think that?
when i get the reading from the MG811 Module is 73 mV only
and reading dose not change when i breath on it :(
only it change when just power on,
the reading decrease from around 100mV
the sensor powered only on 5V
i didnt power it with else
thanks very much,

Comments

  • kwinnkwinn Posts: 8,697
    since the sensor can be powered by AC or DC reversing it should not do any harm.
  • SayedSayed Posts: 4
    edited 2015-09-17 10:35
    thanks very much kwinn,
    i just connect the sensor alone to 5V and read the output from it and it give 650mV
    that like it work, and the module board have problem,
    any easy way to connect the sensor to Arduino safely?
    i think the board i have for MG811 damage,
    can i connect the MG811 on MQ135 board?
    similar to the following?
    can i remove the MQ135 and place the MG811?
    http://www.dx.com/p/fc-22-i-noxious-gas-mq-135-ammonia-gas-sensor-module-blue-silver-193001#.VfqZhRGqqko
  • i just test MG811 also on MQ135 module ‏
    i note that the output from the sensor which around 400 mA decrease when it connected to the module!‏
    and it change some time it go to 600mA‏
    but the module decrease the output!
    any help?
  • kwinnkwinn Posts: 8,697
    The MG811 sensor outputs a voltage proportional to the CO2 concentration while the MQ135 sensor changes it's resistance in proportion to the concentration. That means they require different circuit boards to produce an output signal, so one will not work properly when it is plugged in to a board meant for the other.
  • can you help me with easy and simple way to get MG811 work with arduino?
    directly or with some component, in simple way,
    because am not electronic engineer,
    thanks very much for your help,
    best regards,
  • PublisonPublison Posts: 12,366
    edited 2015-09-20 17:18
    Was this item purchased from Parallax? If so, I would point you to tech support:

    support@parallax.com

    or the phone line:

    888-997-8267
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