Esp8266 Arduino programming example - timer and interrupt

Timer and interrupt

ESP8266 Timer0 and Timer1 There are two timers , Its WiFi The function uses a timer . We can only use a certain timer . To avoid crash problems , stay Arduino It is recommended to use... In the framework Ticker instead of Timer. Ticker Perform the same function as the timer .

This example will demonstrate how to use timer and interrupt to realize LED flashing .

The speed calculation formula of the timer is as follows ：

Timer speed (Hz) = Timer clock speed (Mhz) / Preassigned frequency counter

Preassigned frequency counter / The frequency divider divides the above frequency to form a timer “ Tick tock (tick)”（ Increase its counter ）. And then ISR Configured to trigger after a certain number of ticks .

Prescaler is used , Because the timer can only be stored in its counter at most 8/16 position , This means that for 8 Bit counter , They will every 256/16000000 second （16us） overflow , about 16 Bit counter , They will every 65536 / 16000000 second （4us） overflow , This is usually far more than necessary . Prescaler allows it to be scaled to allow longer intervals .

1、 Hardware preparation

• ESP8266 NodeMCU Development board
• LED One
• 470 An ohmic resistor
• There are several DuPont lines
• A data line

2、 Software preparation

• Arduino IDE or VSCode + PlatformIO

In the previous article , How to build ESP8266 The development environment is introduced in detail , Please refer to ：