Ashish Adhikari Posted February 12, 2022 Report Share Posted February 12, 2022 It’s almost Valentine’s Day. This year, instead of giving her a rose bouquet, I wanted to express my love by gifting her an electronic breathing heart. This is yet another "cheap DIY kit" intended for educational purpose. There are a few variations of the breathing LED projects with similar setup, however the one with blue LEDs attracted me a lot. #valentinesDayGift #ArduinoGiftIdea #ElectronicsValentinesDay Video: https://youtu.be/cq6fEPNtxn4 Unpacking The Kit Same as any other cheap DIY kit, this one came in a zip lock bag without any instructions. However, the component values and polarities are vey well denoted on the board, so I did not had Google at all. Inside the zip lock bag you will find: 1 LM358 IC 22 LEDs 6 Resistors 1 47uf Capacitor 1 Push ButtonSwitch 1 Adjustable Tri-Pot and 1 SS8050 NPN Transistor There is no IC base present in this package. However, I would highly recommended using one for your IC. How This Circuit Works To get the fading effect we need to generate a series of triangular waves. Because of the triangular waves, the LED starts glowing slowly and then slowly dims off and the cycle continues. This setup is done using the LM358 IC. LM358 is a dual operational amplifier (Op-Amp) IC, integrated with two op-amps powered by a common power supply. Pins 1, 2, and 3 are one op-amp channel, and pins 5, 6, and 7 are the 2nd op-amp channel. As the capacitor charges and discharges the state of the PIN 3 switches from high to low and based on that the PIN 2 of the op-amp obtains the desire output. If you want to know more about this IC, please check out my "Tutorial No 21 : DIY - IR Module" : https://youtu.be/_M8FQIPi1qk. So, basically the op-amp here is used for voltage level detection. In this circuit, we are applying a voltage on positive pin (PIN-3) and the voltage to be detected is applied at negative pin (PIN-2). The transistor acts as a signal amplifier. You will need this if you are attaching a cluster of LEDs however for just 1 LED you can simply remove it. Soldering Soldering the components to the board was pretty straightforward and relatively trouble free. I just had to pay a bit of attention to the directions of the components when soldering them to the board. I started the project by soldering the IC base to the board followed by the capacitor, transistor, pot and the push button switch. Next, I soldered all the resistors to the board. After that, I soldered all the LEDs to the board, due to the repetitive nature of the LED installation the installation may slightly be tedious. However once you finish soldering all the components, I bet you will feel proud of yourself. Not to mention, the zip lock bag contains few spare LEDs, umm.. a thoughtful addition. Quick Test So this is how it looks like. The effect is a blue heart that increases and decreases in brightness in a cyclical fashion. The speed/depth can be adjusted using the onboard pot. To be very frank, the diffused LEDs make it quite appealing and less glary when you look at it. Cutting The Heart Now that I have all the electronics bit sorted, it was time for me to add the accessories to it. Something just clicked in my mind and I went ahead and cut a "heart shape" from a piece of pallet. I will later stick the circuit board to this heart shaped pallet plank. Sanding the plank well, and adding a bit of olive oil gave the heart shape a shiny, nice and smooth texture. Items Required For the rest of the project I am using a dog made of clay and some broken pieces of artificial plants. It totally depends on you, what you want to add to give your project a super sexy look. Preparing the base Now to house all the bits and pieces that I gathered so far, I need to create a base. For that, I am cutting a 6" x 3.5" pallet plank. All the bits and pieces will be glued to this pallet plank. Assembling The Heart I drilled a hole in the middle of the wooden heart. Through this hole I will pass the wire that will power the circuit board. The power supply to this board is between 4v-6v DC. Any USB interface, or three ordinary dry cells can be used to power this board. The supply voltage to the red LED version is slightly lower than that all other colored LEDs. A 4v power supply can power the Red version; however, other colors need voltage between 4v 5v 6v. Putting All The Bits Together All right, so now its just a matter of gluing all the bits and pieces one by one to the base pallet plank. Demo When you are young and restless, Valentines Day plays a significant role in your life. However, if you are deeply in love with someone who you are going to spend your rest of the life with, everyday becomes Valentines Day for you. Thanks Thanks again for checking my post. I hope it helps you. If you want to support me subscribe to my YouTube Channel: https://www.youtube.com/user/tarantula3 Blog Posts: https://diyfactory007.blogspot.com/2022/02/Valentine-2022.html Video: https://youtu.be/cq6fEPNtxn4 LED Fader: https://youtu.be/IIUsdICycOw DIY - IR Module : https://youtu.be/_M8FQIPi1qk Cos.TV: https://cos.tv/videos/play/34112835833860096 Odysee: https://odysee.com/@Arduino:7/yt5s.com-Cute-Little-Valentine's-Day-Gift:3 Support My Work: BTC: 1M1PdxVxSTPLoMK91XnvEPksVuAa4J4dDp LTC: MQFkVkWimYngMwp5SMuSbMP4ADStjysstm DOGE: DDe7Fws24zf7acZevoT8uERnmisiHwR5st ETH: 0x939aa4e13ecb4b46663c8017986abc0d204cde60 BAT: 0x939aa4e13ecb4b46663c8017986abc0d204cde60 LBC: bZ8ANEJFsd2MNFfpoxBhtFNPboh7PmD7M2 Thanks, ca again in my next tutorial. Quote Link to comment Share on other sites More sharing options...
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