====== 8x P-channel MOSFET - Wemos D1/S2 mini controlled - Versions C4 ======

{{:p-channel-mosfet:board-c4-top.jpg?400|}}

Inspiration by [[https://www.youtube.com/watch?v=AL1_fvPZXMk&t=2s&ab_channel=Everlanders|Everlanders.com Youtube video]]. 

   Q: What is this board good for? 
   A: Automotive use - as this board turns power on/off on the plus wire

The C4 versions are contained within a 100x100mm envelope - including corner mounts, screw holes and PCB

====What is still the same as the Original board:====
   * GND is still a part of the corner mounts
   * it is still possible to manually activate a MOSFET channel using a DIP switch
   * it is still possible to use the "Wemos D1 mini" as the MCU controller (though a "Wemos S2 mini" is now optional)
   * it is still possible to use the very nice 45-degree-angled spring-loaded high-amp Molex connectors

====What is changed (or added):====
Main changes
   * the size of the PCB is 100x83mm - and all screw holes are kept within that frame
   * each of the 8 channels now have a dual-MOSFET option
   * there are 2 versions of the C4 PCB. 
       * C4 maintains all the basic functions of the [[esp8266-d1-mini-8x-relay-shield-c3|'Original' C3]]
       * C4-F have on-board fuse holders - one for each of the 8 channels
   * 12V -> 5V conversion is now done (only) via a switch-mode DC-DC converter module


Minor changes and added options
   * for low amp boards, 3mm holes to hold the MOSFETs in place has been added
   * at the DIP switch, holes have been added (for ease of adding external (miniature relay) control of a channel)
   * using 0805 size components (are easier to hand solder)
   * because the PCB has been re-sized, all copper paths were re-designed
   * added IDC 10-pin option (for easy connect/disconnect of RasPi control pins)
   * added extra pin rows so the dual rows of the "Wemos S2 mini" (ESP32 27-pin) controller connects to the board
   * added a 5V pin-connector at the bottom edge of the board
   * added a GND screw-terminal/connector at the bottom edge of the board
   * added solder stripes to the bottom layer - so additional copper strips can be soldered to the board (2x 64amp strips can be added)
   * additional power-in connectors/options (blade connectors and/or screw-held ring-eye-lets
   * added a DHT22 connection header (S2 mini option on pin D21)
   * on-board low-battery-voltage on/off switch  - so a simple on/off signal can remove power from the MCU (and thus can turn the entire board OFF) - in  low-battery-voltage situations
   * added a 100nF capacitor to the A0 analog input (might help stabilize the analog reading a little bit)

specific for the C4 board: 
   * option to use screw-held ring-eye-lets as power-out connectors

specific for the C4-F board: 
   * choose between sockets for '1808 mini fuses' or 'car-style mini blade fuses'
   * fuses each have a Red LED to show "fuse is blown"