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The Smart Charizard Diffuser is a 2021 DIY Arduino project that puts an ultrasonic mist maker, humidity sensor, Wi-Fi controls and an automatic refill pump inside a Charizard-themed enclosure. It is a maker prototype, not a ready-to-use product or a documented, safety-certified appliance. Its code and parts list also contain contradictions and exposed credentials, so treat the original as a reference—not a copy-and-upload build.
Here’s how the design works, what the project documents, and what to address before attempting a reproduction.
What the project is
Published by Engineering Dads on Hackster.io on August 14, 2021, the Smart Charizard Diffuser combines an Arduino Uno R3, DHT11 temperature-and-humidity sensor, Grove ultrasonic atomizer, 6-volt peristaltic pump and ESP8266-01 Wi-Fi module. LEDs and a piezoelectric transducer add indicators and sound; a custom 3D-printed enclosure supplies the theme.
Four jobs are combined in the design: the atomizer makes mist, the DHT11 measures ambient humidity, the pump moves liquid from a separate reservoir into the diffuser, and the ESP8266 connects the Arduino to Blynk for remote controls and readings. The project page calls it an essential-oil diffuser, but does not establish that all oils or mixtures are compatible with its pump, tubing, wick, adhesives or printed plastics.
#1 Best Overall
- Humidifier & Aromatherapy Diffuser: The latest raindrop humidifier can be used as an air humidifier and essential oil diffuser. The room humidifier uses high-frequency ultrasonic vertical atomization to send dispersed and diffused water mist to high places. Moisturizing Spray The fine texture can improve air quality, relieve study and work stress, and soothe your mood. Helps improve breathing and sleep, and reduce skin dehydration caused by dry weather.
- 3-IN-1 Function : This 3-IN-1 air device can be used as a humidifier, an essential oil diffuser, and can also be used together with night lights. Drip your favorite essential oil into the water tank to experience the comfort of aromatherapy. At the same time as fragrant, humidify and moisturize the air around you.
- Bedroom Kids Humidifier Ambient Light and Romantic Raindrops: Create a Romantic Ambience & Ideal Gift,The soft gradient LED lights and falling raindrops create a magical, relaxing atmosphere loved by both kids and adults. A thoughtful gift for women, mom, wife, or housewarming for bedrooms, nurseries, and offices.
- The humidifier has four timer settings: spray mode and raindrop mode. The timing function is 2 hours/4 hours/8 hours/continuous. Each button has multiple functions and can be switched freely. The humidifier has a water tank of approximately 350ML, designed with a large diameter for easy water filling. In any mode, no water will automatically protect the shutdown.
- Classic Aromatherapy Humidifier:This raindrop aromatherapy humidifier does not come with a remote control.The essential oil diffuser uses 24V high power to improve the atomization quality and widely expand the aroma. Products and services:1 X Raindrop aromatherapy humidifier,1 X power cord,1 X user manual
The project page marks the build “Advanced.” Its visible text does not give reproducible enclosure dimensions, print files, filament, wall thickness or tolerances, nor a complete pin-by-pin wiring table. It lists an Anycubic 4Max Pro 2.0 among the tools, but that alone is not enough to reproduce the enclosure.
Parts and software
The Hackster bill of materials names an Arduino Uno R3, four-pin DHT11, Grove water atomizer and driver, 6V Grothen peristaltic pump, ESP8266-01, LM2596 buck converter, 1N4001 diode, resistors, two LEDs, piezoelectric transducer, power supply, jumper wires, vinyl tubing, cotton wick, reservoir and custom enclosure. The exact specifications for some components are not sufficiently clear to assume that arbitrary substitutes will work.
There is a particularly important discrepancy in the pump-switch component. The project narrative refers to an n-type MOSFET, the written materials section lists a TIP120 NPN transistor, and Hackster’s generated parts list labels an “IGBT Single Transistor, 120 A.” These are different device types, not interchangeable names. Do not wire a substitute based on that list alone: identify the actual part, check its pinout and drive requirements, and confirm its current and thermal ratings for the pump.
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1Repair Windows errors before they cause bigger problems2Scan for outdated or missing drivers - takes under a minute3Clear out junk files and repair common Windows errorsThe source sketch is Smart_Diffuser.ino, in the Engineering Dads GitHub repository. The project also attributes an approximately 105 kHz operating frequency to its atomizer driver. Treat that as a claim about the described module, not a universal specification for ultrasonic atomizers; check the documentation for the exact driver and transducer you have.
Rank #2
- 【Sound spray dancing jellyfish】Air diffuser has 6 jellyfish spray holes, Humidifier spray dancing jellyfish mist according to the sound changes. Watching the jumping jellyfish is very interesting
- 【Three kinds of spray】Sound jellyfish dancing spray---the aromatherapy machine heard the sound of dancing jellyfish. Automatic jump jellyfish spray -Scent diffuser automatically sprays fog like mushrooms randomly.Flame spray -Oil diffuser directly sprays mist like flame,Choose the fog you like to watch to relax your mood
- 【Colored lights provide atmosphere】Jellyfish diffuser has a color-changing light function and a seven-color light selection. The color-changing light function allows the light color to change automatically, which is suitable for providing a lighting atmosphere at parties, festivals, birthday celebrations and other occasions. The seven-color light selection allows you to choose your favorite light color, which is suitable for providing an atmosphere at home or in the bedroom when sleeping, studying, thinking or doing yoga. There is always a light color that suits your mood
- 【Translucent black shell】The shell of the volcano diffuser is a semi transparent black crack, and the light shines through the shell, like volcanic lava. When the jellyfish mist ring of the aromatherapy machine sprays out, it dances like jellyfish on the volcanic capacity, like jellyfish jumping out of volcanic lava
- 【 Hotel Collection diffuser oils set (4x10ml)】 Get the premium hotel experience at home! Comes with four distinct 10ml essential oils: Happy (uplifting), Sweet (delicate), Mysterious (intriguing), and Relaxation (calming). Transform your air into a signature spa-like retreat instantly
How the system is intended to work
The described power architecture starts with a 12V supply for the pump path. An LM2596 buck converter reduces that voltage to approximately 6V, and a transistor switches the pump on the low side. A diode is placed across the inductive pump load to suppress its voltage spike when switched off. The atomizer driver operates the ultrasonic element; the Arduino reads the DHT11 and controls the atomizer, pump, LEDs and buzzer. An ESP8266-01 communicates with the Arduino over a serial connection, while Blynk provides remote controls and sensor reporting.
This is an architectural summary, not a verified wiring recipe. The original documentation does not resolve the switching-device mismatch or supply a complete wiring table. Confirm the exact modules, ratings, pinouts, power requirements and connections before energizing anything.
Humidity control: a single threshold, not room regulation
In automatic mode, the sketch compares the DHT11 reading with 80% relative humidity: below 80%, it switches on the atomizer and both LEDs; above 80%, it switches them off. The code does not explicitly handle a reading of exactly 80%. It also rejects a not-a-number sensor result, but the documented logic does not provide broader plausibility checks or calibration.
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This is a simple threshold toggle, not a robust room-humidity controller. There is no hysteresis, so readings that vary around 80% can make the output switch repeatedly. A more stable controller would use separate on and off thresholds, plus suitable minimum on/off times. Choose and validate those values for the actual sensor and use rather than treating the original threshold as a recommended room target.
Rank #3
- 【Hotel Collection diffuser oil Scents】Essential oil diffuser included 1.76floz(50 ML) Hotel Collection diffuser oil , Turn on the aroma diffusers and add a few drops of essential oils, emits a pleasant aromatherapy scents at home
- 【Volcano and flame modes 】Aroma diffuser has 2 modes - flame and volcano. Volcano diffuser spray mode like erupting from a volcano, flame diffuser spray mode burning in the air like fog. bring you different experiences, Allow you to experience the scene of flames erupting even at home/bedroom/largeroom
- 【2-color lighting】Aroma diffuser has two options: red and blue light, simulating the light of volcanic eruptions and flame burning. The semi transparent shell allows the entire aromatherapy diffuser to emit special light, allowing you to enjoy volcanoes and flames at home
- 【Keep the air moist for a long time】The spray of the Humidifierr is used for 12-48 hours, volcanic diffuser is used for 48 hours, flame humidifier is used for 12 hours. The sprayed water vapor keeps the air moist, making your throat and body healthier
- 【 Automatic shutdown】Aroma diffuser silently sprays delicate mist and automatically shuts off when the water runs out. Let you focus on work or enjoy leisure time surrounded by fragrant mist
Sensor placement matters too. Humidity close to the mist outlet may differ from humidity elsewhere in the room. A sensor exposed directly to the plume can report local conditions and trigger behavior that does not reflect the room as a whole.
Manual controls and code map
The code provides a physical button on Arduino pin 7, configured with INPUT_PULLUP. Its intended behavior is toggle-style: one press turns on the atomizer and LEDs, the next turns them off. The sketch also assigns Blynk virtual pin V2 to diffuser on/off, V3 to pump on/off, V4 to manual/automatic mode, V5 to humidity and V6 to temperature. The button logic and comments are awkwardly structured, so regard this as the intended behavior rather than a polished interface.
| Function | Sketch assignment or interval |
|---|---|
| DHT11 data | Arduino digital pin 2 |
| Atomizer control | Pin 3 |
| Right LED | Pin 6 |
| Physical mist button | Pin 7 |
| Left LED | Pin 8 |
| ESP8266 software serial | Pins 9 and 10 |
| Pump control | Pin 11 |
| ESP8266 serial baud rate | 112,500 |
| USB/Arduino serial monitor | 115,200 baud |
| Pump cutoff | 35,000 ms (35 seconds) |
| Button debounce delay | 20 ms |
| Blynk sensor update / connection check | 1 second / 5 seconds |
These are settings in the historical sketch, not assurances of compatibility with every ESP-01, board setup or current Blynk library. In particular, 112,500 baud is an unusual project-specific setting; confirm the module’s configured rate and serial wiring if it will not connect.
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Refilling: the timer is not a level sensor
The creator describes a separate sugar-container reservoir with a drilled outlet, vinyl tubing attached using an adapter and hot glue, and cotton wicks soaked in the liquid mixture. In the code, the pump stops after approximately 35 seconds; flashing eye LEDs indicate that the timed fill cycle has reached its limit.
Rank #4
- ✅ 7 COLORS MODES FLAME EFFECT - This flame diffuser is perfect for your ultrasonic aromatherapy; it can collect light and mist to create a natural flame effect like a sunset lamp by switching between 7 colors flame light mode. You can add few drops of your favorite essential oils into the flame diffuser to relieve your daily fatigue and stress, improve sleep quality, moisturize your skin and bring you a pleasant and relaxing mood.
- ✅ 4-IN-1 VERSATILE & PORTABLE - This flame humidifier can be used as an aromatherapy diffuser, mist humidifier, romantic mood light and night light; it is easy for you to carry with its compact and portable design; it can also obviously improve your home air smell while raising the air humidity of your bedroom. 100% perfect for your home / office / yoga / sleep use, and it is also a great gift choice for your friends, family, or loved ones.
- ✅ OPERATES IN TOTAL SILENCE - Enjoy your sleep like a baby! This flame diffuser can steadily and efficiently dispense the soothing cool mist you desire without any humming, whistling, or crackling sound (less than 30dB). SLEEP better, BREATHE better, and LIVE your life better!
- ✅ AUTO SHUT-OFF PROTECTION - This flame diffuser is made of food-grade PP material and it will shut down automatically if water runs out in the tank which makes it extremely safe and reliable for your daily use. THERE IS NO NEED TO LOOK ANY FURTHER FOR THE COOLEST FLAME DIFFUSERS ON THE MARKET!
- ✅ HASSLE FREE WATER REFILLING - You can refill water into the essential oil diffuser directly from the top without the need to take off the outside shell. The upgraded transparent inner tank design with an obvious red maximum waterline will make it extremely easy for you to view and refill water without any leakage.
That cutoff measures elapsed time, not liquid level. It does not prove the diffuser is full or reliably prevent overflow. Delivered volume will depend on the pump, supply voltage, tubing, reservoir height, leaks, priming and restrictions. Measure the real flow and test with a contained setup, but do not rely on the timer as the sole overflow safeguard. A physical level sensor, float switch, overflow route or independently limited reservoir is a stronger design approach.
Problems to address before building
- Replace exposed credentials. The public sketch contains fields that appear to hold Wi-Fi credentials and a Blynk authentication token. Do not reuse them or publish them again. Treat them as compromised; create fresh credentials and keep them out of publicly shared code.
- Verify the pump driver. Resolve whether the intended switch is a MOSFET or TIP120, and do not infer that the generated IGBT label is correct. Check part identity, pinout, drive, current and heat requirements.
- Design for liquid and electricity together. Keep the reservoir, tubing and wet components physically separated from electronics. Use a sealed liquid path, strain relief and drip loops, and add appropriate current limiting or fusing. Keep mains wiring enclosed and inaccessible; do not improvise exposed mains connections. Test for leaks outside the final enclosure first.
- Account for ESP8266 power and logic. The ESP8266 needs an appropriate 3.3V supply and compatible signal levels. Arduino Uno signals, serial wiring, supply capacity and shared grounding all need checking; inadequate power or incompatible levels can cause failures or damage.
- Plan for cleaning and materials. The project does not provide a detailed cleaning, water-change or drying procedure. Water-bearing paths and wicks can become contaminated. Check chemical compatibility of oils with every wetted material and avoid assuming that a mixture is safe to inhale or suitable around children, pets or people with respiratory sensitivities.
- Do not assume the enclosure is moisture-proof. A printed decorative box is not inherently a safe electronics enclosure. Use a moisture-resistant, nonflammable arrangement and ensure any spill or leak cannot run onto energized parts.
A safer reproduction sequence
- Read the project page and inspect the source sketch. Do not upload it unchanged; remove credentials and review its behavior first.
- Identify exact component models and obtain their datasheets. Resolve the switch-device conflict and verify the pump, atomizer driver, power supply, buck converter and diode ratings and polarities.
- Build and test subsystems separately: read the DHT11; test LEDs and button; test the atomizer driver with its specified element; then test the pump through the buck converter using a current-limited supply and the protection diode.
- Keep the liquid path separate from the electronics during leak checks. Verify tubing connections, pump priming and actual flow into a measured catch container before installing anything in the enclosure.
- Test the 35-second cutoff with the actual tubing and reservoir arrangement, but add an independent means of preventing overflow. Check failure conditions such as a blocked tube, stuck switch or power interruption.
- Only after local operation is understood, add Wi-Fi and Blynk. Create a fresh device configuration and credentials. The 2021 page does not provide a verified current Blynk setup, library versions or compatibility guide, so do not assume its cloud integration still works unchanged.
- Install the libraries and board support required by the code you choose, then compile and test each integration step. The sketch uses a DHT library, Blynk, ESP8266 serial communication and SoftwareSerial in its Arduino environment; exact versions and current API compatibility are not established by the project page.
For a new design, an ESP32 can replace the Uno-plus-ESP-01 arrangement and reduce serial and wiring complexity. A local-only controller avoids cloud credentials and dependency. Either redesign still needs suitable power, liquid separation and independent level/overflow protection; these are recommendations, not features of the original build.
Troubleshooting by symptom
ESP8266 does not connect
Check that credentials are fresh and correct, TX and RX are crossed as required, the module has a stable 3.3V supply with adequate current, and the Arduino-to-ESP8266 signals are compatible. Confirm the module’s actual baud rate rather than assuming the sketch’s 112,500 setting. Blynk API or library changes since 2021 may also prevent the historical code from working unchanged.
The pump runs but no liquid moves
Verify pump polarity and voltage under load, buck-converter output, tubing connections and leaks, reservoir height, trapped air, priming and wick blockage. Check that the chosen transistor switches fully without overheating and that the diode is connected with the correct polarity.
Best Value
- 【Diffuser & Humidifier & Night Light 3 IN 1 】- Multifunctional Aroma Humidifier can also be worked as a Humidifier / Aroma Machine / Night Light. Add a few drops of your favorite aromatherapy oil to relieve fatigue and relaxation, while also improving air quality and keeping away from dryness.
- 【7 Colors LED Flame-Effect Lights】- There are many colors and rotating colors chosen to create a nice ambience in your bedroom at night. The mist and light functions of this aromatherapy diffuser work separately. You can turn off the light at night while sleeping. Or use this diffuser as a nightlight.
- 【Ultra-Silent & Auto Shut-Off Function】- Our aromatherapy diffuser featuring an ultra-quiet operation mood of 25dB peaceful environment to help soothe your mood, relieve stress & improve your sleep quality. And, with the help of built-in intelligent chip, Air diffuser will automatically stop working when there is a lack of water, making it very safe and reliable.
- 【Perfectly Release Your Fatigue】- Put the essential oil inside, This essential oil diffuser fills the space with a lovely fragrance that can uplift spirits and relieve stress from stressful and tired day, help to get peaceful sleep surrounded by the aromatic fragrance.
- 【Stylish Gift 】- Our flame design is perfect for any decor. It’s great to fit for the bedroom, loft, office and everywhere you want to put it. and it is the perfect gift for your family or friends.
The diffuser overfills
The 35-second timer is only a runtime cutoff. Stop testing, contain the liquid and measure actual flow. Add a physical overflow path or level-sensing safeguard; do not treat flashing LEDs or a timer as proof of a full reservoir.
The atomizer makes no mist
Check the exact driver/transducer pairing, supply and connections, liquid contact and wick condition. Do not run an element dry. Frequency and voltage requirements depend on the specific module, so verify its own documentation rather than relying on the project’s approximate 105 kHz description.
Humidity control switches erratically
The single 80% threshold has no hysteresis. Improve the code with distinct on/off thresholds and minimum switching times, and place the sensor away from the immediate mist plume.
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Investigate pump current spikes, ESP8266 supply demand, shared grounding, back-EMF suppression, long jumper wires and electrical noise from the atomizer driver. Keep wiring short where practical and provide appropriate decoupling based on the modules’ requirements.
Who should build it?
This project is best suited to experienced Arduino and fabrication hobbyists who want to learn about sensors, actuators, IoT and enclosure design—and are prepared to correct incomplete documentation. It is a poor choice for a beginner expecting a reliable copy-and-upload build, anyone seeking a certified humidifier, or an unattended bedroom or nursery installation without substantial redesign and safeguards.
The Hackster page labels the project GPL3+. Check the applicable license terms before redistributing modified code, diagrams or enclosure assets. The source page and repository are useful references, but neither supplies measured mist output, pump flow, power consumption, noise, runtime or a complete safety design. For someone who mainly wants scheduled operation, a commercial diffuser with a suitable smart plug may be simpler; it will not provide this project’s sensor feedback or automatic refill system.
Quick Recap
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