<p>The ESP32-Node is designed to be a low-cost, vanila solution for experimenting with embedded and IoT devices. The ESP32-Node is intended to College students taking Electronics program or advanced users who are looking for functional ESP32 embedded board with minimal size.</p>
<p>ESP32-WROOM-32D modules are well suited for Wi-Fi and Bluetooth/Bluetooth LE-based connectivity applications and provide a solid dual-core performance. These modules target a wide variety of applications, ranging from low-power sensor networks to the most demanding tasks, such as voice encoding, music streaming and MP3 decoding.
<p>The adapter allows interchangability of ESP32 modules between different nodes. The adapter contains minimal components on its PCB, just enough to ensure module's operation. (ESP32 8-N-1)</p>
ESP32-C3 is a cost-effective, RISC-V-based MCU with Wi-Fi and Bluetooth 5 (LE) connectivity for secure IoT applications. ESP32-C3 Module offfers a cost-effective RISC-V MCU with Wi-Fi and Bluetooth 5 (LE) connectivity for secure IoT applications. [^5]
<p>These modules have a rich set of peripherals and high performance make the two modules an ideal choice for smart homes, industrial automation, health care, consumer electronics, etc</p>
<p>ESP32-C3 has 32-bit RISC-V-based MCU single-core processor with 400KB of SRAM, which is capable of running at 160MHz. t has integrated 2.4 GHz Wi-Fi and Bluetooth 5 (LE) with a long-range support. It has 22 programmable GPIOs with support for ADC, SPI, UART, I2C, I2S, RMT, TWAI, and PWM.</p>
ESP32 modules can be programmed using USB-UART adapter connected to the corresponding UART pins on the ESP32 module. This approach allows to save space on PCB boards, which is very helpful when PCB dimentions have constraints.
ESP Nodes performing specific operations can use different ESP32 Modules for optimization purposes. As dicersity of ESP32s being used by the Nodes increases, so does the code. However, in order to keep core code independent from the ESP32 Module being used, the so-called configurations specific for the particular ESP32 Module are defined in config.h file.
The LM75A is an industry-standard digital temperature sensor. The LM75A provides 9-bit digital temperature readings with an accuracy of ±2°C from –25°C to 100°C
and ±3°C over –55°C to 125°C. The LM75A operates with a single supply from +2.7 V to +5.5 V. Communication is accomplished over a 2-wire interface which operates up to 400kHz.
The LM75A has three address pins, allowing up to eight LM75A devices to operate on the same 2-wire bus. The LM75A has a dedicated over-temperature output (O.S.) with
programmable limit and hysteresis. This output has programmable fault tolerance, which allows the user to
define the number of consecutive error conditions that must occur before O.S. is activated.
BME280 is combined temperature, humidity and pressure sensor. The unit combines high linearity and high accuracy sensors and is perfectly feasible for low current consumption, long-term stability and high EMC robustness. The humidity sensor offers an extremely fast response time and therefore supports performance requirements for emerging applications such as context awareness, and high accuracy over a wide temperature range.[^2]
Below is the functional diagram of BME-/BMP-280. Notable difference between the two devices, is that BME-280 is capable of measuring relative humidity. BME-280 has square shape, while BMP-280 has rectangular shape.
> BM**E**280[^2] and BM**P**280[^3] look almost identical. However, BME280 sensor has a square form, while BMP280 has a rectangular form. In addition, the two sensor boards can have different I<sup>2</sup>C addresses.
The BME280 sensor board interface uses 4 pins and is 13mm by 10.5mm in size. The four pins are `VIN`, `GND`, `SCL` and `SDA`. The measured values are sent via I<sup>2</sup>C protocol. The I<sup>2</sup>C slave address is pre-defined and can take value either 0x76 or 0x77 (BME280 Datasheet, page 32)[^4].
<p>Data readout is done by starting a burst read from 0xF7 to 0xFC (temperature and pressure) or from 0xF7 to 0xFE (temperature, pressure, and humidity). The data are rad out in an unsigned 20-bit format both for pressure and for temperature, and in an unsigned 26-bit format for humidity. After the uncompensated values for pressure, temperature, and humidity have been read, the actual humidity, pressure and temperature needs to be calculated using the compensation parameters stored in the device.</p>
ESP RainMaker is a complete, yet light-weight, AIoT solution that enables private Cloud deployment for your business in a simple, cost-effective and efficient manner. ESP RainMaker is a light-weight AIoT Cloud software, fully integrated into the AWS serverless architecture, which allows customers to build, develop and deploy customized AIoT solutions with a minimum amount of code and maximum security. [^7]
