Button Archives | ArunEworld

Whan captures button presses and counts the number of pulses generated by these presses. Below is an explanation of the code “ESP8266 266 NodeMCU Interface Button”.

The button interface is a fundamental component in electronics and user interfaces, offering users a simple yet effective way to interact with devices.It consists of a push mechanism and contacts, completing an electrical circuit when pressed to trigger predefined tasks. Additionally, buttons are essential components in electronic devices, facilitating user input and control. Various types of buttons exist, including momentary buttons, toggle switches, and membrane buttons, each tailored to specific applications.

Consumer electronics, industrial control panels, automotive interfaces, and medical devices widely utilize buttons. Design considerations such as size, shape, color, and placement are crucial for usability. Incorporating debounce circuitry is also essential to eliminate bouncing effects. While buttons provide intuitive interaction and are cost-effective, they have limitations such as limited input options and potential wear over time. Additionally, designing interfaces with multiple buttons can pose challenges regarding space constraints and user ergonomics.

Uses – Button

Uses of Button Interface	Example
1. Input Sensing	Detecting button presses for menu navigation
2. User Interaction	Initiating actions such as turning on/off devices
3. Control Mechanism	Controlling the speed of a motor based on button input
4. Event Triggering	Triggering alarms or notifications
5. User Feedback	Providing feedback through LED indicators
6. Configuration Settings	Adjusting settings in a user interface

Advantage and Disadvantage

Advantages	Disadvantages
Simple and intuitive user interaction	Limited input options compared to touchscreens
Cost-effective and easy to implement	Physical wear and tear over time
Tactile feedback provides confirmation	Limited functionality for complex interactions
Suitable for applications requiring precise input	Limited space for multiple buttons on small devices
Works reliably in various environments	May require debouncing to prevent false triggers

Importance of Buttons

ESP8266 NodeMCU Interface Button .Buttons are essential components in various electronic systems and interfaces for several reasons:

Importance of Buttons	Description
User Interaction	Buttons facilitate direct user interaction with electronic devices, enabling input commands.
Control	They provide users with control over device functions and operations, enhancing usability.
Feedback	Buttons offer tactile feedback upon pressing, confirming the user’s action.
Versatility	Buttons can be integrated into various devices and interfaces, offering versatile functionality.
Reliability	They are known for their durability and consistent performance, ensuring reliable operation.
Cost-Effectiveness	Buttons are cost-effective components, making them widely used in different applications.

Overall, buttons play a crucial role in enabling user interaction and control in electronic systems, thereby making them indispensable in many applications across industries.

Types of buttons

Button Types	Description
Push Button	Typically a simple momentary switch that closes a circuit when pressed and opens it when released.
Tactile Button	Features a small, tactile protrusion on the surface, providing physical feedback upon pressing.
Toggle Switch	A mechanical switch with a lever or toggle that can be flipped or moved to open or close a circuit.
Rocker Switch	Similar to a toggle switch but with a flat, paddle-like actuator that rocks back and forth to toggle.
Slide Switch	Utilizes a sliding mechanism to open or close the circuit, often used for simple on/off operations.
Capacitive Touch Button	Operates through touch-sensitive materials, activated by the presence of a conductive object or a finger.
Membrane Button	Consists of a flexible membrane with conductive traces, pressed to make contact with underlying circuits.

These button types offer various tactile and operational characteristics suitable for different applications.

Button Interrupt Counter

The Button Interrupt Counter script counts the number of button presses (pulses) detected on a specific GPIO pin (in this case, GPIO2 or GPIO9).

Required

NodeMCU Modules (Firmware): GPIO Module, Timer Module,
hardware: ESP8266 with Programmer (or) NodeMCU Dev Kit, Button,
software tools: ESPlorer IDE Tool.

Code

The script tallies button presses (pulses) detected on GPIO2, which corresponds to GPIO9. It incorporates debouncing to prevent counting multiple pulses for a single press.

-- Source URLs and Testing Information
-- http://esp8266iot.blogspot.in/
-- http://aruneworld.blogspot.com/
-- Tested By: Arun(20170219)
-- Example Name: AEW_ButtonInterruptCounter.lua
------------------------------------------------------------------------------------------

-- Count pulses on GPIO2
count = 0
delay = 0

-- Configure GPIO9 (equivalent to GPIO2) for interrupt mode with pull-up enabled
gpio.mode(9, gpio.INT, gpio.PULLUP)

-- Interrupt handler function
function counter(level)
    local x = tmr.now() -- Get current time in microseconds
    if x > delay then
        delay = tmr.now() + 250000 -- Update delay to allow for the next pulse after 250 milliseconds
        count = count + 1 -- Increment pulse count
        print(count) -- Print the current count value
    end
end

-- Set up interrupt trigger on GPIO9 for falling edge detection
gpio.trig(9, "down", counter)

Code Explanation

Source URLs and Testing Information:

Two URLs are provided as the source of the code: http://esp8266iot.blogspot.in/ and http://aruneworld.blogspot.com/.
The code was tested by Arun on a specific date mentioned as 20170219.
The example is named AEW_ButtonInterruptCounter.lua.

Initial Variables Setup:

count: Initialized to 0, it will be used to count the pulses detected on GPIO2.
delay: Initialized to 0, it will be used to debounce the input and avoid counting multiple pulses for a single press.
gpio.mode(9, gpio.INT, gpio.PULLUP): Configures GPIO9 for interrupt mode with pull-up enabled.

Interrupt Handler Function (counter):

tmr.now(): Retrieves the current time in microseconds.
If the current time is greater than the delay value, it means that enough time has passed since the last pulse.
In such a case, the delay is updated to allow for the next pulse after a debounce period of 250 milliseconds.
The count variable is incremented to keep track of the number of pulses detected.

Setting up Interrupt Trigger:

gpio.trig(9, "down", counter): Sets up an interrupt trigger on GPIO9 for falling edge detection. When a falling edge (button press) is detected on GPIO9, the counter function is called.

Interrupt Example of ESP8266 NodeMCU Interface – Button

Code

do
    -- use pin 1 as the input pulse width counter
    local pin, pulse1, du, now, trig = 1, 0, 0, tmr.now, gpio.trig
    gpio.mode(pin, gpio.INT)

    local function pin1cb(level, pulse2)
        print(level, pulse2 - pulse1)
        pulse1 = pulse2
        trig(pin, level == gpio.HIGH and "down" or "up")
    end

    trig(pin, "down", pin1cb)
end

Code Explanation

This code segment configures GPIO pin 1 of the NodeMCU board as an input for pulse width counting. Here’s a breakdown of what it does:

Overall, this code enables GPIO pin 1 to monitor pulse width changes and execute the callback function accordingly, providing a way to measure the duration of pulses on the input pin.

Variable Initialization:

pin: Specifies GPIO pin 1 for pulse width counting.
pulse1: Tracks the start time of the pulse.
du, now: References to tmr.delay and tmr.now functions for timing operations.
trig: Reference to the gpio.trig function for setting up interrupts.

GPIO Configuration:

Sets GPIO pin 1 as an interrupt-enabled pin (gpio.mode(pin, gpio.INT)).

Callback Function:

Defines a callback function pin1cb(level, pulse2) to be executed when an interrupt occurs on pin 1.
The level parameter indicates whether the interrupt is triggered by a rising edge (gpio.HIGH) or falling edge (gpio.LOW).
pulse2 represents the time when the interrupt occurred.

Callback Logic:

Calculates the pulse width by subtracting the previous pulse time (pulse1) from the current pulse time (pulse2).
Prints the level (indicating rising or falling edge) and the calculated pulse width.
Updates pulse1 to store the current pulse time for the next interrupt.

Trigger Setup:

Sets up the interrupt trigger using gpio.trig(pin, "down", pin1cb).
The trigger is set to detect falling edges ("down") on pin 1 and execute the pin1cb callback function.

Interrupt

The Button Interrupt Counter script showcases the effectiveness of utilizing interrupts in microcontroller programming. By leveraging interrupts, the script efficiently responds to button presses without the need for continuous monitoring. This approach optimizes the utilization of system resources and enables the microcontroller to perform other tasks while waiting for button input.

Furthermore, the script demonstrates an essential concept in embedded systems programming: debouncing. This feature enhances the reliability and accuracy of the button press count, making the script suitable for applications where precise user input tracking is essential.

Overall, the Button Interrupt Counter script exemplifies best practices in microcontroller programming by combining interrupt-driven design with debounce mechanisms to achieve robust and efficient button input handling.

NodeMCU Get Start

NodeMCU Build Firmware

NodeMCU Flash Firmware

NodeMCU IDE

ESP8266 NodeMCU Modules

NodeMCU Module–Firmware Info

NodeMCU Module – GPIO

NodeMCU Module – Node

NodeMCU Module – WiFi

NodeMCU Module – Timer

NodeMCU Module – I2C

NodeMCU Module – File