Introduction: LiPo to MicroUSB Adapter
In anticipation of my Raspberry Pi arriving I have created a LiPo (Lithium Polymer) to Micro USB adapter. This adapter converts the power from a 2s – 4s LiPo to a regular 5v. This is then outputted through a Micro USB to be plugged into a Raspberry Pi board. I will be using this to power the Pi when I use it as a ground station for my Arducopter (Which will be a whole new Instructable).
Unfortunately due to the frustration of my PCB etching attempts failing I forgot to take build photos. I only took a few once I was finished, hopefully it will be enough. I hope you all can figure out how it all fits together from the diagrams and photos. I have tried my best to explain what I did.
Please let me know if there is anything confusing you.
Step 1: What You Need
- 1x veriboard/perfboard
- 1x 7805 Voltage regulator
- 2x 25v 10uf electrolytic capacitors
- 1x Micro USB cable
- 1x Deans Plug (Whatever Plug you use on your LiPo’s)
- 1x Small cable tie
- Side clippers
- Soldering Iron
- Heat source to shrink the heat shrink (I used a hair dryer)
- Hack saw to cut the board down to size
Step 2: Failed PCB's and Schematic
My original plan was to print my own PCB and use that but after two failed attempts I gave up and simply build a simpler version on Veriboard. Once I was thoroughly frustrated from my one hundredth attempt at printing my own PCB failing, I drew up a schematic of a very simply Voltage regulator circuit. The capacitors are not strictly needed as this is not rectified AC but it doesn't hurt to put them in.
Step 3: Building
I did not cut the board first which I think made it a lot harder later on. I would place the parts and determine the size of veriboard needed. Cut it first it will make life ten time easier later! I wanted to make this board as small as possible so I place the regulator on the top and the capacitors on the bottom of the board. I put the ground pins for both of the capacitors through the same hole to make it slightly smaller. On either side on the MicroUSB cable I drilled 2mm holes and treaded a small cable tie through. This will prevent the cable from ripping out at any point.
Step 4: Finishing Up
All that remains is to put heatshrink tubing over the entire board to prevent shorting during use. I used a hair dryer to shrink the tubing, I find it has sufficient heat to shrink all types of heatshrink.
See the image of the board powering a USB to SATA driver board.
The nice thing about this board is that you can simply replace the MicroUSB cable with a cable to charge your phone or iPod. Meaning you can venture out into the wild and still charge your devices using a large LiPo.
I hope you enjoyed reading this as much as I will enjoy using it!
If I can get my PCB etching working I will finish building my V2 board which has a voltmeter and an LED on it which will prevent over usage of the LiPo (If it works, a new instructable will be on its way soon).