My problem is I don’t have direct sunlight into my room at daytime, that I could use it to charge up the Sun Jar. To charge it, I’ll have to bring this Sun Jar out to my corridor to charge it up, and bring it in at the night. So, I decide to power the Jar up using my USB port, but the whole jar is made of Glass, that I cannot drill a hole for my wire to go into the jar, so, I come out with this idea of creating wireless power to power up the jar.
Besides of the Crystal Oscillator, I also add in a push button, a LED, and for the output, I use 2N2222 transistor to drive it, to ensure that it provide sufficient current to power up the coil. About the push button S1, there is no need to put extra pull-up resistor because PIC12F683 do support internal weal pull-up on its I/O. You’ll just need to configure that in your coding.
One thing to take care while soldering the UMK8 is try to leave some space between the Crystal Oscillator and the PCB, because it is double layer pad, try to prevent the body of the Crystal Oscillator touching the pad, or it is better if you have a plastic spacer in between them.
More information about UMK8 Here:
UMK8 Product page
Then, connect the coil to the LED, directly, one wire to one pin, and mount that LED together with the Solar LED in the Jar. I keep the whole Solar system of the Jar, that I could still “capture” sunlight if I want, and this wireless power will work independently. So, I could use either “sunlight” or Wireless Power, and they didn’t affect each other.
Secure the Wireless Power LED to the Solar LED using Shrink tube. Try not to put them side by side that they might block each other lighting.
So, the coil will be place inside at the bottom of the Jar, and the wireless power comes from the bottom, while the solar power from the top.
For the coding for UMK8, you can download the complete project at the end of this article. The coding basically generating a pulse to the coil, and the button is to turn the pulse On or Off. Try to refer to the comment in the coding and do leave comment here if you have any doubt about the code.