myDevices Cayenne allows you to quickly design, prototype, and visualize IoT solutions. You can use Cayenne as a tool to visualize real-time and historical data, sent over to The Things Network. Let’s discuss “ESP8266 Arduino-Core Cayenne – Get Start with Cayenne MyDevice“
Cayenne is a platform for building IoT (Internet of Things) projects that provides tools for creating dashboards, monitoring devices, and controlling connected devices remotely. The Cayenne platform supports various microcontrollers and single-board computers, including the ESP8266, through the use of Cayenne MQTT or Cayenne MQTT API.
Bosch Sensortec developed the BMP280 as a barometric pressure sensor. It’s designed with high accuracy and precision to measure atmospheric pressure and temperature. The sensor is commonly used in various applications such as weather stations, altitude measurement, indoor navigation, and IoT (Internet of Things) devices.
The BMP280 sensor utilizes a MEMS (Micro-Electro-Mechanical Systems) pressure sensor to detect atmospheric pressure changes. Additionally, an integrated temperature sensor provides temperature measurements. These measurements enable the calculation of altitude and provide data for weather forecasting, environmental monitoring, and other applications.
This sensor communicates with microcontrollers or other devices via standard interfaces like I2C (Inter-Integrated Circuit) or SPI (Serial Peripheral Interface). Consequently, it’s easy to integrate into a wide range of electronic systems.
Where Buy this Sensor
Ebay
Amazon
Aliexpress
Data Sheet
BMP280 Pressure Sensor
Suggest to study
ESP8266 NodeMCU – Pressure Measurement using BMP280 Sensor
Uses
The BMP280 sensor finds applications in various fields due to its ability to measure barometric pressure and temperature accurately. Consequently, here are some common uses:
Weather Stations: These stations often employ this sensor to monitor atmospheric pressure and temperature, providing data for weather forecasting and analysis.
Altitude Measurement: Altimeters use it to determine altitude above sea level by measuring changes in atmospheric pressure with elevation.
Indoor Navigation: In combination with other sensors, this device contributes to indoor navigation systems by providing altitude and temperature data for positioning and orientation.
Drones and UAVs: These unmanned aerial vehicles (UAVs) use the BMP280 for altitude control and navigation, enabling precise altitude hold and flight stabilization.
Environmental Monitoring: Environmental monitoring systems use the sensor to measure atmospheric conditions in indoor and outdoor environments, including air quality assessment and pollution monitoring.
IoT (Internet of Things) Devices: Various applications integrate the BMP280 into IoT devices, including smart home automation, agricultural monitoring, and industrial control systems.
Automotive Applications: In automotive applications, the BMP280 can monitor cabin pressure, compensate for altitude in navigation systems, and control climate.
The ESP32 NodeMCU module supports the I2C (Inter-Integrated Circuit) communication protocol. With its built-in hardware support for I2C, the ESP32 NodeMCU module can easily interface with various I2C devices such as sensors, displays, and other peripherals. This allows for efficient data exchange between the ESP32 and I2C devices, enabling a wide range of applications in IoT, robotics, automation, and more.
Send (SW) or queue (HWx) I²C address and read/write mode for the next transfer.
i2c.read()
Read (SW) or queue (HWx) data for a variable number of bytes.
i2c.setup()
Initialize the I²C interface for master mode.
i2c.start()
Send (SW) or queue (HWx) an I²C start condition.
i2c.stop()
Send (SW) or queue (HWx) an I²C stop condition.
i2c.transfer()
Starts a transfer for the specified hardware module.
i2c.write()
Write (SW) or queue (HWx) data to the I²C bus.
i2c.slave.on()
Registers or unregisters an event callback handler.
i2c.slave.setup()
Initialize the I²C interface for slave mode.
i2c.slave.send()
Writes send data for the master into the transmit buffer.
Code of ESP32 I2C Scanner
In this code used to can the i2c Devices
Used Software i2c and GPIO-23 as SDA and GPIO-22 as SCL of I2C Device
Connected DS3231 Device and check i2c address of DS3231
-- setup
id = i2c.SW -- Software
pinSDA = 23 -- 1~12, IO index
pinSCL = 22 -- 1~12, IO index
speed = i2c.SLOW -- only i2c.SLOW supported
--Initialize
i2c.setup(id, pinSDA, pinSCL, speed) -- Initialize the I²C module.
print("Scanning Started....")
for count = 0,127 do
i2c.start(id) -- Send an I²C start condition.
Status = i2c.address(id, count, i2c.TRANSMITTER) -- Setup I²C address and read/write mode for the next transfer.
i2c.stop(id) -- Send an I²C stop condition.
if Status == true then
print("Addrss - "..count.." Detected device address is 0x" .. string.format("%02x", count) .. " (" .. count ..")")
elseif Status == false then
print("Addrss - "..count.." nil")
end
end
print("Scanning End")
This table format provides a structured breakdown of each section of the code along with its explanation.
Section
Explanation
Setup Section
id
Defines the I2C interface as software-based.
pinSDA
Specifies the GPIO pin used for the data line (SDA) of the I2C interface.
pinSCL
Specifies the GPIO pin used for the clock line (SCL) of the I2C interface.
speed
Sets the speed of the I2C communication to slow. Only i2c.SLOW speed is supported.
Initialization
i2c.setup()
Initializes the I2C module with the specified parameters: interface ID, SDA pin, SCL pin, and speed.
Scanning for Devices
print(“Scanning Started….”)
Prints a message indicating the start of device scanning.
Looping through device addresses
Iterates through device addresses from 0 to 127.
i2c.start()
Sends an I2C start condition.
i2c.address()
Sets up the I2C address and read/write mode for the next transfer.
i2c.stop()
Sends an I2C stop condition.
Check Status
Checks the status of the address detection: If Status is true, prints the detected device address in hexadecimal and decimal format. If Status is false, prints “nil” for the address.
print(“Scanning End”)
Prints a message indicating the end of device scanning.
ESP8266 and ESP32 NodeMCU Lua Module functions are different. So we can’t use ESP8266 fuctions directly in ESP32 Check the Official Documentation of NodeMCU Lua for ESP32
AosongDHT11 is a low cost humidity and temperature sensor with a single wire digital interface. The sensor includes a resistive sense of wet components and an NTC temperature measurement devices, and connected with ahigh–performance 8–bit microcontroller. DHT11 uses a simplified single-bus communication. The sensor is calibrated and doesn’t require extra components so you can get right to measuring relative humidity and temperature.
DHT11 output calibrated digital signal. It utilizes exclusive digital-signal-collecting-technique and humidity sensing technology, assuring its reliability and stability. Its sensing elements are connected with 8-bit single-chip computer. Every sensor of this model is calibrated in accurate calibration chamber and the calibration-coefficient is saved in type of programmer in OTP memory, when the sensor is detecting, it will cite coefficient from memory. for more details about data sheet of DHT11 sensor click here.
Lua RTOS is an open-source real-time operating system (RTOS) designed to run Lua applications on microcontrollers and other embedded systems. It aims to provide a lightweight and efficient platform for developing embedded applications with Lua scripting capabilities.Here will discuss ESP32 Lua RTOS Flash Firmware tutorial.
Overall, Lua RTOS is a versatile and lightweight operating system that empowers developers to build embedded applications with Lua scripting capabilities. Its integration with popular microcontroller platforms and active community support make it a compelling choice for IoT and embedded systems development. We tested with EPSressif ESP-Wroom-32 Dev Board and ESP32 Core firmware with the ESPressif Flash tool.
Lua RTOS is built on Lua, a lightweight scripting language. Lua is known for its simplicity, ease of use, and flexibility, making it ideal for embedded systems development.
Real-Time Operating System
Lua RTOS provides a real-time operating system (RTOS) environment for embedded systems. It offers task scheduling, inter-task communication, and synchronization mechanisms.
Supported Hardware
Lua RTOS supports various microcontroller architectures, including ESP32, ESP8266, STM32, and others. It is highly portable and can be adapted to different hardware platforms.
Multitasking
Lua RTOS enables multitasking, allowing multiple Lua scripts to run concurrently as separate tasks. Tasks can communicate and synchronize through message passing and semaphores.
File System
Lua RTOS includes a file system API for accessing files on external storage devices such as SD cards or SPI flash memory. It supports file operations like reading, writing, and listing.
Networking
Lua RTOS supports networking protocols such as TCP/IP, UDP, MQTT, and HTTP. It allows embedded devices to communicate over Ethernet, Wi-Fi, or other network interfaces.
Peripheral Support
Lua RTOS provides APIs for interfacing with various peripherals such as GPIO, UART, SPI, I2C, ADC, DAC, and more. Developers can easily control and communicate with hardware components.
Development Environment
Lua RTOS development can be done using lightweight text editors or integrated development environments (IDEs) with Lua support. It offers flexibility in choosing development tools.
Community
Lua RTOS has an active community of developers and users who contribute to its development, share knowledge, and provide support through forums, mailing lists, and social media.
This table summarizes the key features and characteristics of Lua RTOS, providing an overview of its capabilities and suitability for embedded systems development.
Setting up Lua RTOS
Step
Description
1. Obtain Lua RTOS
Download Lua RTOS from the official repository or source.
2. Install prerequisites
Install any required dependencies, such as Git and GCC, according to Lua RTOS documentation.
3. Set up development environment
Configure your development environment, including setting up a terminal and text editor.
4. Initialize project directory
Create a new directory for your Lua RTOS project.
5. Write your Lua code
Develop Lua scripts and application logic within the project directory.
6. Configure Lua RTOS
Customize Lua RTOS configuration files to match your project requirements.
7. Compile Lua RTOS
Use the provided build system to compile Lua RTOS for your target hardware platform.
8. Flash Lua RTOS
Flash the compiled Lua RTOS image to your target hardware using tools like esptool.py.
9. Test your application
Verify the functionality of your Lua RTOS application on the target hardware platform.
10. Iterate and improve
Continuously refine your Lua RTOS application based on testing feedback and requirements.
Firmware
Where to get Lua-RTOS firmware? (Pr-compiled binaries)
Download the appropriate firmware for your ESP32 board from the provided link. Once you’ve downloaded the appropriate firmware, unzip the file anywhere on your machine. Similarly, download the Flash tool from the same link and unzip it. Next, open the flash tool designed for ESP32 and configure the following parameters:
Baud rate: 921600
Flash mode: “dio”
Flash frequency: “40m”
For flashing the firmware, use the following addresses:
Once the flashing process is complete, you’re all set.
Note: Make sure to adjust the “esp-idf path” and “usb path” as per your requirements.
Connect to the Console
Connect any UART Serial Tool to your device and configure the following parameters:
Speed: 115200 bauds
Data bits: 8
Stop bits: 1
Parity: None
Terminal emulation: VT100
Ensure these settings are accurately configured for seamless communication between your devices.
after connecting esp32 to the PC you will see the following.
/\ /\
/ \_____/ \
/_____________\
W H I T E C A T
Lua RTOS beta 0.1 build 1479953238 Copyright (C) 2015 - 2017 whitecatboard.org
cpu ESP32 at 240 Mhz
spiffs0 start address at 0x180000, size 512 Kb
spiffs0 mounted
spi2 at pins sdi=012/sdo=013/sck=014/cs=015
sd0 is at spi2, pin cs=015
sd0 type II, size 1943552 kbytes, speed 15 Mhz
sd0a partition type 0b, sector 227, size 1943438 kbytes
fat init file system
fat0 mounted
redirecting console messages to file system ...
Lua RTOS beta 0.1 powered by Lua 5.3.4
Executing /system.lua ...
Executing /autorun.lua ...
/ >
In this “ESP32 Lua-RTOS Modules- Basic Examples” article we will explore the PIO Module (GPIO) and Interface LED as well as Buzzer, Wifi, MQTT, EEPROM I2C Code.
In this article we are discussing Embedded Interface – PCF8574 and PCF8574A I/O Expender.
The PCF8574 device provides general-purpose remote I/O expansion for most micro controllers families by way of the I2C interface [serial clock(SCL), serial data (SDA)]. 8-bit 2.5- to 5.5-V I2C/SMBus I/O expander with interrupt
The device features an 8-bit quasi-bidirectional I/O port (P0–P7), including latched outputs with high current drive capability for directly driving LEDs. Each quasi-bidirectional I/O can be used as an input or output without the use of a data-direction control signal. At power on, the I/Os are high. In this mode, only a current source to VCC is active.
UART (Universal Asynchronous Receiver/Transmitter) is a standard communication protocol used for serial communication between devices. It’s commonly employed in embedded systems for communication between microcontrollers, sensors, and other peripheral devices.
In the context of embedded systems, UART is often used as a hardware communication protocol, enabling devices to transmit and receive data serially. The UART communication involves two pins: TX (transmit) and RX (receive).
It’s is full-duplex communication
UART contains a shift register
which is the fundamental method of conversion between serial and parallel forms.
Type of Communication: Asynchronous (No clock).
Rule: The transmitter and receiver should same baud rate. Data format and transmission speed are configurable.
UART Uses serial communication over a computer or peripheral device serial port. (Electronics Devices).
SPI is an abbreviation for Serial Peripheral Interface, which stands for Synchronous Serial Communication Interface. It is utilized for short-distance communication and was developed by Motorola in 1980, later becoming a de facto standard. SPI communication operates in full-duplex mode. It is also sometimes referred to as the Four-Wire Serial Bus (FWSB), distinguishing it from Three, Two, and One Wire Serial Bus protocols. The four-wire protocol includes SCL, SS, MISO, and MOSI. SPI operates as a single master protocol.
Message Queue Telemetry Transport (ISO/IEC PRF 20922), or MQTT, is a lightweight protocol designed for machine-to-machine (M2M) device communication using a Publish/Subscribe pattern. It was developed by Message Queue Telemetry Transport (ISO/IEC PRF 20922) and Lightweight protocol for (M2M) device communication using Publish/Subscribe. It was Developed By Andy Stanford-Clark (IBM) and Arlen Nipper (Eurotech; now Cirrus Link) in 1999. Unlike HTTP, which follows a request/response paradigm, It utilizes a publish/subscribe architecture. The central communication point in It is the Broker. It is available for implementation in C, C++, JavaScript, Lua, Python, and soon in C#.
Client functions
Field
Description
Host
Address of the MQTT broker.
Port
Default: 1883.
ClientID
Unique client identifier.
Username
UTF-8 encoded string for authentication.
Password
Client’s password if flag set.
Keep Alive
Duration client stays connected (seconds).
SSL
Indicates SSL/TLS encryption usage.
Clean Session
If set, session clears subscriptions and messages.
Last-will Topic
Topic for “Last Will” message on disconnect.
Last-will QoS
Quality of Service for “Last Will”.
Last-will Retain
Retain status for “Last Will” message.
Last-will Message
Content of “Last Will” in case of disconnection.
Topic
Message destination hierarchy.
+ Plush sign
Single-level wildcard in subscriptions.
# Hash Sign
Multilevel wildcard in subscriptions.
Publish QoS
Quality of Service levels:
QoS(0) – At most once
QoS(1) – At least once
QoS(2) – Exactly once
Retain
Message retention by broker.
Subscriptions
List of subscribed topics.
Message
Payload data transmitted.
Broker
Server distributing messages.
Client
Device or app connected to broker.
Quality of Service
Message delivery guarantee.
Retained Messages
Broker-stored messages for new subscribers.
Persistent Session
Broker-maintained session after client disconnects.
Last will and Testament and SYS topic
Client’s “Last Will” message and system topics interaction.
DIOT which stands for Decoupled IOT, has its SCADA functionalities decoupled into Host and Node for flexibility and scalability that catered for IoT era. This plugin functions as the SCADA Host to work with your device or system, which will be treated as SCADA Node. You just need to enter the broker/server into the configuration. You may then subscribe to the desired topic with a shortcode to display in any desired web page or post. [diot topic="building/floor/device/sensor"] Or, if you have a JSON content, you may add dollar sign as JSON root: [diot topic="building/floor/device/sensor$json.data"]. The content will be updated dynamically when the device publish any data. You may also choose to display your realtime data in trending chart. Check out Ecava DIOT online demo to see how easy things can be done now! For more see here : https://wordpress.org/plugins/ecava-diot-scada/
Setting up Tthis is easy. Simply supply your MQTT broker’s details and configure which WordPress events should trigger messages. “MQTT is a machine-to-machine (M2M)/”Internet of Things” connectivity protocol. It was designed as an extremely lightweight publish/subscribe messaging transport.” (from mqtt.org) A number of events are predefined. Simply check the right checkbox and fill in the message’s subject and text.
Pageview
User login
Failed user login
Post published
Page published
New comment
Other events can be added using the “custom events” section. This allows you to use any WordPress hook (actions and filters) to trigger messages.
COAP, or Constrained Application Protocol, a specialized web transfer protocol, is designed for constrained devices and low-power, low-bandwidth networks commonly found in Internet of Things (IoT) and Machine-to-Machine (M2M) applications. CoAP is an application layer protocol similar to HTTP but optimized for constrained environments.
This, designed to be simple and lightweight, is ideal for resource-constrained devices, operating over UDP instead of TCP to reduce complexity. It supports request/response interactions like HTTP and offers features such as multicast support and resource discovery. CoAP facilitates efficient communication between constrained devices and web servers, fostering the development of scalable IoT solutions.
Getting Started with Terminal by Br@y tool
Terminal is a simple serial port(COM) terminal emulation program
Used for communication with different devices (Modem, routers, embedded uC systems, GSM Phones. GPS Modules)
Very useful debugging tool for serial communication applications
I²C (Inter-Integrated Circuit) is a bi-directional two wires and serial data transmission communication protocol developed by Philips (Now NXP Semiconductor) in 1982. I2C is a Half-duplex communication protocol – (I2c can’t send and receive same time in the bus-data line). Multi-master can communicate with multi-salve. (Note: Communication is restricted between two masters; however, a single master can communicate with either a single slave or multiple slaves.) I2C is a Level Triggering. A device that sends data onto the bus is defined as a transmitter, and a device receiving data is defined as a receiver.
The bus must be controlled by a master device, responsible for generating the Start and Stop conditions. In contrast, certain devices such as LCDs, EEPROMs, and RTCs function as slaves. It’s important to note that both master and slave devices can operate as either transmitters or receivers. However, the master device plays a pivotal role in determining which mode is activated.
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