• Ok, that is a clickbait-y title, no real progress so far, but maybe there will be some :)

    I must admit, this was kind of an impulse buy after finding out that Xiaomi's Bluetooth temperature & humidity sensor probably has an nRF chip, and Sensiron sensor.
    Edit: Part no lLYWSDCGQ/01ZM, got from Aliexpress

    My original plan was to add a CCS811 (air quality sensor), and probably drop in an ISM radio because the walls in my house are thick (40-45cm), and 2.4Ghz just doesn't penetrate that thick walls well. At the time couldn't find more info about it, so just ordered.
    Or just use 'em in the rooms close to the Pi (to collect data) if all fails...

    Got them today. First impression & teardown with unsorted photos :

    The good:

    • Ordered 3 of them, the measured values are <0.5°C and <1% RH apart. Those things react fast to temp or humidity changes.
    • Nicely constructed, You can take it apart and reassemble no problems.
    • Looks like they really have Sensiron SHT30, manufactured in 2018. The sensor sits in a small opening, connected with a flex pcb to the main PCB.
    • It has test points! I think I have found power pins, SWD pins, and SDA, SCL to the SHT30.
    • The LCD driver has is manufactured by Rohm, and has a datasheet

    The bad:

    • Turns out, some more googling could have revealed the exact parts before purchasing...

    The ugly:

    It does have an nRF chip: nRF51802

    The nRF51802 is a low cost variant of the nRF51822, it has the same functionality, but has minor performance degradation in terms of:

    • 2 dB less RX sensitivity
    • Slightly higher RX and TX peak currents

    That's like the MCU in the micro:bit with worse RF performance :/

    Couldn't figure out the type of the DC-DC converter so far, so no idea how much current can it provide. Might not be enough for an ISM radio.

    And of course I need some extra pins too...

    So right now not so sure about Espruino. Maybe if I can strip out bluetooth from the nRF51 build to free up some memory? Or just try to do it in C? Or reassemble the unit, and place 'em in locations with good bluetooth reception? :)


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