This simple fixture will help you evaluate the ripple of your lighting and select non-ripple lamps. You can assemble it in just five minutes.
To my cry for the creation of a "people's pulse meter" (https://ammo1.livejournal.com/1289621.html) many people responded In the comments on Zen, Vyacheslav T said that there is a ready-made pulsation sensor produced by the Moscow company iArduino. It is called "Light sensor, lux meter, FLASH-I2C (Trema-module)"and costs 320 rubles. This sensor is built on the APDS-9930 sensor, which is actually a proximity sensor, but at the same time it can measure illumination. The sensor contains its own processor and sends the illumination in lux, the ripple in percent and the distance to the object via the I2C bus. The iArduino website says that ripple is calculated from the last 20 light measurements. With what frequency the measurements are made and by what formula the ripple is calculated is unknown. I specially went to iArduino to find out the technical details, but they said that the sensor was developed for a long time and they do not remember anything.
I bought a sensor, assembled the device and studied how it works.
The sensor does not take into account the background illumination; therefore, it is advisable to carry out measurements in the dark, so that the test lamp is the only light source.
I took LED lamps of different quality with different levels of pulsation and compared the readings of a homemade pulse meter with the readings of the Uprtek MK350D spectrometer and the Radex Lupin device.
"Uprtek MK350D" and "Radex Lupine" calculate the ripple coefficient using different formulas, so their readings differ. The readings of the homemade device on the iArduino sensor are close to the readings of the MK350D, which reads the ripple using a simplified formula. The absence of ripple (0%) and small levels of ripple (1-50%), the homemade device shows confidently and accurately enough. With a pulsation of 100%, the readings of a self-made device begin to jump from 0 to 100%, but from this "jumping" one can understand that the lamp is completely bad.
In the second line, the homemade device shows the illumination in lux.
I made a short video with an experiment comparing instrument readings.
https://www.youtube.com/watch? v = RmGDyjKBS-0
In order to make the same device yourself, you will need a sensor "iArduino Light sensor, light meter, FLASH-I2C (Trema-module)" (you can buy here), 0.96 "OLED screen with 4 pins (I2C) (available for purchase here or here), D1 mini board (you can buy here or here) or, if you don't want to solder anything, the Arduino Nano (you can buy here or here) or Arduino Uno (you can buy here or here).
Four pins of the light sensor and four pins of the screen are connected to the same pins of the microcontroller: VCC to 5V, GND to GND or G, SCL to D1 for "D1 mini" or A5 for Arduino boards, SDA to D2 for "D1 mini" boards or A4 for boards Arduino. The Arduino Uno board has all these pins duplicated, so one board (for example, a screen) can be connected to 5V, GND, A5, A4, and the second (for example, an iArduino sensor) to 5V, GND, SCL, SDA.
The device can be used without a screen: all information is simultaneously output to the serial port and can be viewed in the monitor of the Arduino port.
You will need libraries to compile iarduino_I2C_DSL and
GyverOLED.
Everything you need (sketch, libraries, connection diagram) can be downloaded in one archive here.
But do not rush to run to iArduino for the sensor. As I said at the beginning, many people have not responded to my call and two have already created much more advanced heart rate meters.
Stanislav Gritsinov has developed a pulse meter with an analog TEMT6000 sensor and a TFT screen.
Nikolay Khozyainov (director of R-LABS) made a pulse meter with a small solar battery as a sensor and an OLED screen.
In the near future we will bring the "people's pulse meter" to perfection and I will publish a detailed instructions for assembling it, in addition, it may be possible to make it so that the ready-made pulse meter can will buy.
© 2021, Alexey Nadezhin
For ten years I have been writing every day about technology, discounts, places of interest and events. Read my blog on the site ammo1.ru, v LJ, Zen, Mirtesen, Telegram.
My projects:
Lamptest.ru. I test LED lamps and help figure out which ones are good and which are not so good.
Elerus.ru. I collect information about domestic electronic devices for personal use and share it.
You can contact me in Telegram @ ammo1 and by mail [email protected].