• First code without WiFi

    MaBe4201/15/2022 at 15:09 0 comments

    I wrote some initial code for the basic functionality, i.e. switching on/off the individual LEDs/LED strips by toggling buttons. 

  • Schematic

    MaBe4201/07/2022 at 15:23 0 comments

    I typically use the Wemos D1 mini dev board because of its size and because I can still program it directly via USB. My LED strips are for 12V but the schematic should work also for 24V (with the necessary adpations). As Mosfets I use IRLU024N. They are logic level and not very expensive. Although the schematic shows a maximum use case, I only put the components onto a perfboard that I really need for a particular use case.

    Depending on the dev board I use a 5V or 3.3V supply (5V for the Wemos D1 mini). This can be done by a linear regulator (which requires a heat sink) or a switch mode DC-DC converter. Max. current of 500 mA is sufficient. Since the ESP tends to draw quite some current when sending on WiFi I added a 100uF electrolytic cap.

    Some people advice pull-down resistors (e.g. 10k) at the gates of the mosfets to avoid initial undefined states but I don't care.

    The LED strips that I use draw 2-3 A. So I do not need any heat sink for the mosfet. Switching more than 5A is possible but requires thinking about possibly using a heatsink.

    The numbers in the schematic designate the GPIOs not any pin numbers.

    Concerning the ADC (if used): The ADC of the ESP 8266 is limited to 1V. The Wemos D1 mini is designed such that it can handle up to 3.3V. Other boards might be different.