• Actual weather data!

    Lee Stephens08/24/2018 at 15:58 0 comments

    We have weather data! Well, I can print indoor temperature, humidity and pressure to the serial port. But it’s a start. 

    Best get on with the MQTT broker and the node-red and InfluxDB elements.

  • Lolin 32 or is it?

    Lee Stephens08/22/2018 at 13:14 0 comments

    The first of the stuff from eBay arrived today.

    The Lolin 32 (I actually think it's a Lolin 32 Lite) arrived:

    I plugged it into a USB port on my hackinosh, and the LED on 22 flashed. :)

    I had to download Arduino IDE again (rebuilt hackintosh since last programming stuff). Also followed the instructions to install the ESP32 capability. Of course, it didn't show up in the IDE under the Tools->Ports. After a big of google-fu and head scratching, I remembered that when I ordered some clone Arduino nanos (some time ago) I had to install some drivers. Inspecting the board (you can see a 16 pin chip bottom left) it says CH340G and this matches the link I found last time. I installed the drivers, selected Board: Wemos Lolin 32, Flash: 80Mhz, Upload speed: 921600, Port: /dev/cu.wchusbserial1410.

    I got the example "Blink" sketch. Hit compile & upload and it completed. Except nothing flashed.

    Then I realised that the standard sketch assumes a standard Arduino and the pin with the LED is 22 on the board above. So I changed that and it worked!

    Also checked the WiFi scan sketch and that worked too.

    When the batteries arrived, I tested one of the 18650 Li-ion cells at 3.8V. Having disconnected the USB, I tried plugging it into the holder and touching the wires to the battery leads on the board, and that worked too.

  • Building the Raspberry Pi with Raspbian Stretch Lite and 'the script'

    Lee Stephens08/22/2018 at 13:14 0 comments

    It worked.

    But now what.

  • Building the Raspberry Pi with Diet Pi and 'the script'

    Lee Stephens08/22/2018 at 13:13 0 comments

    It doesn't work.

  • Ordering some stuff

    Lee Stephens08/22/2018 at 13:12 0 comments

    Ok, so I went mad on Amazon and eBay. Here's what I ordered:

  • Overall thoughts on pre-build​

    Lee Stephens08/22/2018 at 13:12 0 comments

    Overall thoughts on pre-build

  • Requirements

    Lee Stephens08/22/2018 at 13:11 0 comments

    Let's split the requirements into three.

    First, outside the house:

    Name Description Type
    Temperature Record the current temperature to a minimum of 0.5 of a degree celsius Must
    Humidity Record the humidity as a percentage Must
    Pressure Record the pressure in millibar Must
    Wind speed Record the average wind speed over a ten minute period, record the highest gust over a 0.25 second period1 Should
    Wind direction Record the average wind direction over a ten minute period Should
    Rainfall Record rainfall in mm Should
    Sunshine Record minutes of direct sunshine Should
    Unattended operation The device should need no physcial attention. Obviously there will be a need for maintenance, but this should be kept to a minimum Should
    Low cost On the basis that it may be damaged or stolen, it would be good to keep the costs low Should
    Battery powered Be capable of being powered by batteries for an extended time period. Must
    Solar charge Use a solar cell to recharge the battery, hopefully to avoid the need to change the batteries Should
    Aesthetically pleasing The sensors should be housed in an aesthetically pleasing housing, suitable for the garden Should
    Able to cope with being outside Electronics will need to be kept dry, power must be supplied even in low temperatures. Must
    No local storage Recordings should be sent into a central service for long term retention and visualisation


    Secondly, the data storage system:

    And finally, the visualisation and end user experience: