New PCB: Power IR Sensor with boost converter / Signing support questions

  • Hardware Contributor

    I am currently working on a small sensor platform for my mysensors setup. The idea is too support different types of sensors like I2C ones, an IR Module, and all kinds of analog sensors.
    As I plan to drive the board via coincell and some sensors need a stable 3.3V input I also want to include boost converter. The radio and atmega would be powered directly from the source to avoid any problems while the sensor can be powered from the boost converter.
    I also wanted to disable the boost converter and sensors if they are not need to increase efficiency. Thats why I also added a transistor to control them. After the boost converter I added a choke+cap to filter out noise... will that be enough for an IR module to run without problems from the boost converter?
    Does the power control (with the transistor) work like this?
    For signing I also added an ATSHA204A chip. Are the one cap and the pullups on the I2C lines enough to make it work? Do you need anything else for signing?
    Do you see any other errors or stuff that I could add? Any feedback is welcome!

    Thanks for your help! Once I am done creating the board I will open a project on to share it with you.

  • Hardware Contributor

    Ok I finally got my parts and started testing. When running the IR sensor directly from the boost converter to get stable 3.3V it doesn't work (it only sends random on/off signals). I think I remember reading something about the noise problems somewhere here in the forum, but can't remember any solutions.
    Does anyone of you have such a solution up and running?
    Could a low pass filter like this help?

  • Hardware Contributor

    Well it looks like that doesn't help 😞 Btw I am using the "normal" cheap 5V ones from ebay but soldered the 3.3V directly to teh small "H" pad at the side (worked without problems from a good power source). Any other ideas guys?