›

Haptic Rating for Sensor

CarltonGucCarltonGuc
in Python

I have a sensor that samples the air that has a heater (MiCS-5524). I'm using the Haptic circuit to turn power on for the heater. It seems to be working, however there is concern that I might be causing damage for the MetaMotionR+ board. The sensor then basically reads a voltage and I do so by:

                gpio.Pins[1].ClearOutput();

And have a resistor between GPIO 0 and GPIO 1.

My question for the forum is if this seems to be correct or if I will end up having issues long term? I am seeing a failure in some devices and don't know if the Haptic circuit is failing.

Thanks
Carlton

Comments

  • LauraLaura
    edited January 2020

    There are three modes:

    • GpioPullMode.NONE == Floating (Tied to nothing, detached, no electricity can flow through)
    • GpioPullMode.DOWN == 0V (Tied to ground)
    • GpioPullMode.UP == 3V (Tied to power)

    You should use the correct mode to turn the sensor on/off for readings depending on its datasheet and your circuit setup.

    Now you can only damage the board if you push too much current or voltage through so just be careful that the heater specs match the SOC (CPU) specs.

    My question for the forum is if this seems to be correct or if I will end up having issues long term? I am seeing a failure in some devices and don't know if the Haptic circuit is failing.

    You could be harming the SOC (CPU) if you go above 3V or if you sink/source more than 20mA. Normally you should power the heater from the battery and only use the SOC (CPU) to turn it on/off. You can use a FET to further protect the SOC (CPU).

  • CarltonGucCarltonGuc

    I would be using SetOutput and ClearOutput to control the GPIO? Or do I also have to call SetPullMode?

    Thanks
    Carlton

  • MattMatt

    @carltonguc I would have to see a circuit to fully understand what you are describing and whether there are further hazards beyond those described by @Laura . Note that the haptic module always applies a duty cycle and this may interfere with your sensor, or may be why it appears to be failing.

  • CarltonGucCarltonGuc

    I'm shifting over to a different option and plan to use this: https://www.adafruit.com/product/3709 and connect to the I2C bus.

Sign In or Register to comment.