A thermistor (THERMally sensitive resISTOR) is an electrical resistance whose value changes with the temperature. Thermistors are divided into two groups, hot conductors which have a negative temperature coefficient (NTC), conduct electrically in a hot state better than in the cold state and cold conductors, which have a positive temperature coefficient (PTC) and conduct better electrically when … [Read more...]
IoT Based Pulse Oximeter With ESP32, MAX30102 and IBM Watson IoT
Pulse oximeters are in use since long during an operation, in intensive care, in the emergency room and other places such as in unpressurized aircraft. The COVID-19 pandemic made pulse oximetry technology for the consumers. Most of the finger pulse oximeters in the market lack BLE and Wi-Fi. There are only a few finger pulse oximeters which have a BLE to transmit data to the smartphone. Having a … [Read more...]
ESP32 MAX30102 Pulse Oximeter Code
In the previous guide of MAX30102, we have shown a test code with the MAX30102 module build/sold by Maker Focus mounted on a MH-ET LIVE breakout board. Our two challenges are - ESP32 is not exactly same as Arduino UNO and the good looking MH-ET LIVE breakout board is not same as the MAX30102 module sold by Sparkfun. As we commonly use the MAX30102 sensor library by Sparkfun, we need to guess which … [Read more...]
Pulse Oximeter with ESP32 and MAX30102
The MAX30100 IC is an integrated pulse oximetry module two LEDs, a photodetector, optimized optics, and low-noise analogue signal processing designed for the wearable devices and medical devices. The MAX30102 IC is an upgrade to The MAX30100 and The MAX30101 IC. Here is the datasheet of MAX30102 (website of MAXIM). The PDF will give you the outlook of the working principle of the thing. … [Read more...]
Required Theory For Unlocking Cars With Smartwatch (ESP32 Arduino)
In this article, we will discuss the opportunities to add a BLE controlled system of ESP32 in parallel to the central lock fitted by the company which will unlock and lock our cars based on proximity of our smartwatches. Our regular readers already learned how to use ESP32 Arduino with a buzzer to detect a Samsung Smartwatch. Also, they can track such events on IBM IoT dashboard. The car's … [Read more...]
ESP32 as Hardware Random Number Generator
The capability of the ESP32 to generate truly random numbers is important for cryptographic operations. A random number generator generates a sequence of random numbers. A hardware random number generator is also known as a true random number generator. It generates random numbers from some physical process, not from code. A fundamental distinction is made between non-deterministic and … [Read more...]
How to Run an ESP32 on Battery
The operating voltage range of ESP32 is 2.2V to 3.6V. The ESP32 boards have an LDO voltage regulator to keep the voltage at 3.3V. The output of the regulator is also broken out to one of the sides of the board and labelled as 3V3 which can be used to supply power to the other components. The VIN pin can be used to directly supply the ESP32 a regulated 5V voltage electricity supply. In other words, … [Read more...]
ESP32 vs Arduino : How ESP32 is Different from Arduino
ESP32 is a low cost, low power consuming System on Chip (SoC) with integrated Wi-Fi and Bluetooth compatible with Arduino IDE. In other words, an ESP32 board can be used as "Arduino" following some guide like we have published one in the past. ESP32 is developed by Espressif Systems and has a Tensilica Xtensa LX6 microprocessor. By the phrase "Arduino", we mean the boards which are designed and … [Read more...]
ESP32 Arduino Smartwatch Detector with Buzzer
The series of article Samsung Smartwatch as Proximity Switch taught our readers to learn all required the basic to make ESP32 to respond to a specific smartwatch's BLE. The same basic was used for the IoT project Detect Smartwatch With ESP32 on IBM Watson IoT Widget. But, still today in everyday life we depend on sound clues more than the visual clues. A door bell or a smoke detector are some … [Read more...]
Detect Smartwatch With ESP32 on IBM Watson IoT Widget
In our previous guide, we have shown that we can trigger ESP32 (with Arduino IDE) to send message to IBM Watson IoT in Presence of a Particular Samsung Galaxy Smartwatch. That process involves BLE and WiFi. In our one series of articles on Samsung Smartwatch as Proximity Switch, we triggered a local event, such as control of a LED. In our other series of articles, we used the IBM Watson IoT … [Read more...]
ESP32 Audio Output
The ESP32 has a built-in 8-bit DAC. Digital to the analogue signal converter or analogue-digital converter or DAC is a device to convert digital signals with binary data into current or analogue voltage signals. For better sound quality, we can use an external I2S codec and amp. Adafruit I2S amp uses a MAX98357A IC. The MAX98357 is a low-cost, digital pulse-code modulation (PCM) input amplifier. … [Read more...]
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