1. Home
  2. Wiki
  3. Firefly Remote
  4. Remote
  5. Battery & power

Battery & power

The first thing you will have to assemble is the battery and power modules. This is because these parts later will be hidden underneth the cover whereupon the Arduino and transceiver lie. To this part of the assembly you will need the following items:

  • Lithium-Ion battery
  • TP4056 charger module
  • 5V step-up module
  • Slide switch
  • Micro USB connector

Important: The TP4056 module is by default capable of supplying 1A of charging current. This is way too much for most small batteries and could damage your battery. The current is determined by the resistor referred to as Rprog, which by default is 1.2 kOhm. A resistance of 5kOhm limits the current to 250mA, which fit this type of battery better. The resistor is very small and difficult to change, so if you need a simpler solution you can use a low current USB charger (100-250mA).

 

Step 1: First thing to do is to cut the battery wires to the right length. Place the battery inside the remote, and measure out the needed amount of wire. Important: Do not cut both wires at the same time, as this could cause a short circuit.

Step 2: Solder the battery wires to the correct pads on the TP4056 module.  Important: Try not to solder anything inside the remote, as the plastic easily melts if a hot soldering iron gets to close.

Step 3: Connect the TP4056 charger module to the 5V boost converter and adds four wires (see the picture below) to be connected later

Step 4: Place the parts inside the remote and cut the wire coming from BAT+ and IN+ so that they can be connected to the switch. Which wire goes to which pin on the slide switch doesn’t matter.

 

Step 5: Solder two small wires to the Micro USB connector. Important: Remember to get the polarity right.

Step 6: Solder the wires coming from the Micro USB to the IN+ and IN- of the TP4056 charger module.

Step 7: Place all the parts inside the remote, and make sure to test the power circuit before continuing. By turning on the power switch a small blue diode should dimly be lit.

Step 8: Secure everything with some hot glue, to prevent anything from shorting.

If everything works, you are ready to continue to assemble the rest of the remote. Let’s get to it!