TSL235R Light-to-Frequency Converter

The TSL235R Light-to-Frequency Converter is a precision optical sensor IC that converts incoming light intensity directly into a digital square wave output signal whose frequency is proportional to the brightness of the light falling on the sensor — brighter light produces a higher output frequency (up to 200-300kHz) and dimmer light produces a lower frequency — making it fundamentally different from analog light sensors like LDRs and phototransistors that output a variable voltage or resistance that must be read through an ADC pin. The light to frequency converter tsl235r outputs a clean digital signal that is read by the microcontroller using a frequency-counting method (pulseIn function or external interrupt) on any digital GPIO pin.

Which eliminates ADC quantization error and gives much higher measurement accuracy and noise immunity than analog light sensing methods for precision light intensity measurement builds. The tsl235r sensor operates from 2.7V to 5.5V supply voltage making it compatible with both 3.3V ESP32 and STM32 boards and 5V Arduino boards without a level shifter, draws only 2mA operating current, and has a peak sensitivity wavelength of 700nm.

The red and near-infrared portion of the visible spectrum — which makes the tsl235r arduino combination particularly responsive to red LED light sources, making it suitable for pulse oximetry experiments, color-filtered light intensity measurements, and LED-based optical communication detection builds.  The -25°C to 70°C operating temperature range covers outdoor and industrial monitoring environments. Available from StemVolt.

Related Products:

• Checkout Laser Receiver Sensor Module

Features:

• Digital frequency output — no ADC needed for light intensity reading
• 200-300kHz range — frequency scales linearly with incident light brightness
• 700nm peak sensitivity — optimized for red and near-IR light sources
• 2.7-5.5V supply — works with 3.3V ESP32 and 5V Arduino directly
• 2mA low current — minimal power draw for battery sensor builds

Technical Specifications:

 Applications:

• Using TSL235R light to frequency converter output
• Builds color sensor with tsl235r sensor red light detection
• For tsl235r arduino frequency-based light intensity measurement
• Optical pulse counter detecting LED flicker with tsl235r 3 pin arduino
• light to frequency converter for frequency counting interrupt

Package Include:

• 1 x TSL235R Light-to-Frequency Converter