Category Archives: Products


Easy Pulse Sensor (Version 1.1) Overview (Part 2)

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In Part 1 of this article, we briefly discussed about the principle of Photoplethysmography (PPG) and its applications in retrieving vital information about the cardiovascular system. The Easy Pulse sensor allows you to measure the pulse rate from fingertip using the transmission mode PPG. The Easy Pulse Version 1.1 uses the HRM-2511-E sensor that fits comfortably onto fingertip. Inside the sensor there is an IR LED that illuminates the finger from one side. A photodetector placed on the opposite side and facing towards the IR LED detects the transmitted light through the finger. The little variations in the transmitted light

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Easy Pulse Sensor (Version 1.1) Overview (Part 1)

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The Easy Pulse sensor is designed for hobby and educational applications to illustrate the principle of photoplethysmography (PPG) as a non-invasive optical technique for detecting cardio-vascular pulse wave from a fingertip. It uses an infrared light source to illuminate the finger on one side, and a photodetector placed on the other side measures the small variations in the transmitted light intensity. The variations in the photodetector signal are related to changes in blood volume inside the tissue. The signal is filtered and amplified to obtain a nice and clean PPG waveform, which is synchronous with the heart beat. The original version

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MAX7219-based double row 4-digit seven segment LED display

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This display board (SPI7SEGDISP8.56-2R) features eight 7-segment displays arranged in two rows of four digits. The on-board MAX7219 driver enables you to control all LED segments through only 3 I/O pins of microcontroller. The major advantage of using this board is the time-division multiplexing operations required for continuous refreshing of the display digits are performed by the MAX7219 chip, thereby keeping the microcontroller free for doing other pressing tasks. The double row arrangement is suitable for many projects where two variable values are to be displayed simultaneously, such as displaying temperature and humidity, or current and voltage, etc.

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TrH Meter kits are back in stock at Tindie

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TrH Meter is a DIY digital room thermometer plus hygrometer that displays temperature and relative humidity on 4 large (1 inch) seven segment LED displays which adjust their brightness level according to the surrounding illumination. It consists of a closed loop system that continuously assesses ambient light condition using an inexpensive light-dependent resistor (LDR) and uses that information to adjust the brightness of the display. An inexpensive DHT11 sensor is used to measure temperature and relative humidity. You can buy a complete TrH Meter kit with a preprogrammed PIC microcontroller  for $26.00. Tindie buying link for TrH Meter kit.

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SPI7SEGDISP8.56 kit is now available with blue seven segment LED displays

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SPI7SEGDISP8.56 is a MAX7219 based serial seven segment LED display module that allows you to add 8 digits of seven segment LED displays to your project using only 3 I/O pins, and provides full control of all the digit segments including decimal points. The LED display size is 0.56″ and all 8 digits are arranged into two rows of four. SPI7SEGDISP8.56 display kit is now also available with blue LED color. You can buy one for $13.50 on Tindie. SPI7SEgDISP8.56-1R Buying links: SPI7SEGDISP8.56 buying link – Red color SPI7SEGDISP8.56 buying link – Yellow color SPI7SEGDISP8.56 buying link – Green color SPI7SEGDISP8.56 buying link

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