With everything soldered underneath the cover, we can move forward to wiring the Arduino.
Step 1: Cut three wires (red, black and white) and wire up the hall sensor. The hall sensor should be wired as follows.
Step 2: Now cut two more wires, and wire up the limit switch (the trigger). We will only be using two of its pins (C and NO), connecting GND to NO and C as an output. To make room for the switch, the legs have to be bent upwards, and the wires soldered close to the housing.
Step 3: Glue the limit switch and hall sensor in place.
Step 4: The Arduino only has one 5V and two GND terminals. As you may already know, we need a little more than that. To make it easier to solder later now is a good time to add an extension wire for the 5V and GND terminal. Tip: Make the extensions of some hard wire (the legs of a resistor will do).
Step 5: Solder the power lines coming from the boost converter to the Arduino 5V and GND. If everything works, the Arduino should light up if you turn on the power switch.
Step 6: Now continue soldering the output wires from the Hall sensor and trigger to the appropriate pins. Hall output goes to pin A3, and trigger output goes to pin D4. For now, let us wait with soldering the power wires (red and black) as more will follow later.
Step 7: Now cut 7 wires (one red, five white and one black) for the nRF24 module, and ready them for soldering. Tip: Add a little solder to the wires so they easily fit in the holes in the solder pads. Align them with a piece of tape.
Step 8: Solder the wires to the nRF24 module, while making sure none of the pads short out. This isn’t easy, and you should take your time to make sure every connection is good. Tip: If possible use a small soldering iron, some thin solder and add some flux.
Step 9: Solder the newly attached wires of the nRF24 module to the Arduino.
Step 10: The OLED often comes with a row of pre-soldered male pin headers. This is not optimal since the pins makes it impossible to get a flush fit. They have to be removed, and that is easier said than done. One way to do it is to simply pull out each pin while heating it with a soldering iron. Important: The OLED display is fragile, and can’t handle much stress, therefore remember to cover it with something soft while working on it.
Step 11: Now cut 4 wires (red, black, blue and white) with a good length and solder them to the OLED displays terminals. Tip: To ensure a long-lasting connection, add a blob of hot glue.
Step 12: Solder the data lines from the OLED to the appropriate pins on the Arduino. SDA goes to A4 and SCL goes to A5.
Step 13: Now solder the rest of the power wires (red and black) to the 5V and GND terminal. This is best done by adding a good bit of solder to the extension wires and soldering each wire one by one.
Step 14: Now get a 10 kOhm resistor from pin A2 and connect with a wire to the battery through the switch.
All electrical soldering is now done, and you should move on to upload the software to see if your newly assembled remote works!