PIC24F Blood pressure monitor

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Digital blood pressure monitors come in handy for checking and monitoring blood pressure at home or in a hospital. This reference design from Microchip provide tips to build a low-cost, low-power, handheld or portable blood pressure meter with user interface using the system-on-a-chip PIC24FJ128GC010 MCU. The meter is used with an inflatable cuff for restricting blood flow and a pump to inflate the cuff, and measures both systolic and diastolic pressures, as well as the heart rate of the patient.

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Bluetooth connected thermometer

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Bluetooth connected thermometers are making their way into many consumer products such as fitness devices, medical activity trackers, BBQ Grills, etc, to allow temperature monitoring through smartphones and tablets. This reference design from Microchip illustrates the implementation of a Bluetooth-connected digital thermometer using Microchip’s PIC16F1519 MCU and RN42 Bluetooth Module. Powered by two AAAA batteries, this design measures temperature in Fahrenheit or Celsius using the Melexis MLX90614 non-contact infrared thermometer sensor. It also implements input touch buttons using mTouch integrated capacitive touch technology. An OLED display on board is used to demonstrate stand-alone design capability, while the Bluetooth module demonstrates smartphone/tablet connected design

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Designing a MPPT solar charger

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Solar panels collect energy from the sun and convert it to electricity. Because the sun is not consistent throughout the day, the output power from the solar cell is also not constant. MPPT stands for Maximum Power Point Tracking and is an electronic system for solar panels that allows them to produce and deliver maximum available power. In a solar-powered battery charging system, it is done by varying the ratio between the voltage and current delivered to the battery. For instance, if there is excess power harvested from the panels during high Sun conditions, the MPPT converts it to additional current to charge the battery much

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A multifunctional Arduino clock

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This multifunctional Arduino clock does more than just showing time. Besides displaying time, date, and day of the week, it also measures the ambient temperature and humidity, runs disco LED lights with music, and has a built-in speaker to hook an audio source like a mp3 player.

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DIY Geiger Counter using 555

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Geiger counters are used to detect beta particles and gamma rays radioactive emissions. The counter consists of a tube filled with an inert gas such as helium, neon, or argon at low pressure, to which a high voltage is applied. The tube becomes conductive of electricity when it is impacted by a high-energy particle or photon. Tanner_Tech‘s Instructable shows how to build the simplest 555 timer based DIY Geiger counter using minimal electronic components. Tanner_Tech‘s design uses 555 timer IC as an astable multivibrator to drive a step-up transformer through a MOSFET in order to generate the high voltage required for

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