Flickering Tealight LED Candle Remix

cults3d

Changelog: Added new 3D models to my current test project. Photos of the newly built model have been included. The printed circuit board was assembled by pinching small cylinders with a soldering iron. This method is not elegant, but it works efficiently. Next on my agenda is designing a printed circuit board and then creating final 3D models. I used black PLA as filament because it was already mounted in the printer. I plan to print the diffuser in white. I found an original solution by bobthechemist very interesting, but it lacked some features I wanted to include. So, I took the code and added a timer and voltage control to protect batteries from undervoltage. There will also be a slightly modified design of the printed candle, but this is not ready yet. Therefore, credits go to bobthechemist for the flicker-code; it looks great. There are three individual variables (located at the beginning of the code) that need to be set: Vwarn: When the battery reaches this voltage, the brightness will be reduced by half. This is clearly visible and should be understood as "Please charge the battery as soon as possible." Vsleep: When reaching this voltage, the whole system will go into a deep sleep to protect the battery. Runtime_hrs: The number of hours from connecting the battery that the LED will remain active. For the rest of the day, the system will sleep. You can also change the intensity and flicker there, but I found it good as it is. Pre-entered values are for a single-cell lithium-ion battery (3.7 V, 150 mAh) and a runtime of six hours. I'm still testing the code, but it appears to work. Please keep in mind that the code is intended for an Attiny85 with a 1 MHz clock frequency. Another Attiny version may require different programming of the registers, and the flickering might look different on other frequencies. The code is some kind of alpha version since there are some lines left for serial communication, and it's not "nice" as this is my first coding attempt after decades off the keyboard. With the current circuit and an Adafruit sequin LED, the system draws around 3 mAh when active and approximately 0.3 mAh when not active. With a runtime of six hours, this translates to around 1 mAh per hour. So, my 150 mAh lithium-ion cell might be enough for four to six days. I am still testing... The text file should work with PlatformIO as .cpp or as .ino in Arduino IDE. I added two pictures of my breadboard testbed with a multimeter measuring the current.