ADC
目录
- Arduino API
- Arduino UNO R3
- STM32F103C8T6 Bule Pill
- ESP32-DevKitC
- MicroPython API
- STM32Cube（待补充）
Arduino API
Arduino UNO R3
/*
Analog Input to PWM LED Brightness Control
This code reads the analog value from an analog input (e.g., a potentiometer) connected to pin A5
and converts it to a PWM signal that controls the brightness of an LED connected to pin 11.
Circuit:
- Analog input (e.g., potentiometer) connected to A5.
- One side of the potentiometer connected to 5V, the other side connected to GND.
- Middle pin of the potentiometer connected to A5 (analog input).
- LED connected to pin 11 through a 220Ω resistor.
Diagram:
+5V ----[Potentiometer]---- GND
|
A5 (Analog input)
Arduino LED
----------- -----
| | | |
| 13 --|----|>|---+---- GND
| (PWM Pin) | (Anode) (Cathode)
| |
The analog input (A5) reads the voltage from the potentiometer and converts it into a brightness value for the LED using PWM.
created 2024
by Liang
*/
void setup() {
// Initialize serial communication at 9600 baud to send data to the Serial Monitor
Serial.begin(9600);
// Set pin 11 as an output for controlling the brightness of the LED
pinMode(13, OUTPUT);
}
void loop() {
// Read the analog input value from the potentiometer connected to pin A5
// The analogRead() function returns a value between 0 and 1023
int analogInputVal = analogRead(A5);
// Map the analog input value (0-1023) to a PWM value (0-255)
// This allows us to control the brightness of the LED using analogWrite() on pin 11
int brightness = map(analogInputVal, 0, 1023, 0, 255);
// Print the raw analog input value to the Serial Monitor for debugging
Serial.print("Analog Input Value: ");
Serial.println(analogInputVal);
// Print the mapped brightness value to the Serial Monitor for debugging
Serial.print("LED Brightness Value: ");
Serial.println(brightness);
// Set the brightness of the LED by writing the mapped PWM value to pin 11
analogWrite(13, brightness);
}
STM32F103C8T6 Bule Pill
/*
STM32F103C8T6 (Blue Pill) ADC with PWM LED Control
This code reads the analog value from a potentiometer or analog sensor connected to PA0 (A0)
and converts it to a PWM signal that controls the brightness of an LED connected to PB1 using PWM.
Circuit:
- Analog input (e.g., potentiometer) connected to PA0 (A0).
- One side of the potentiometer connected to 3.3V, the other side connected to GND.
- Middle pin of the potentiometer connected to PA0 (A0).
- LED connected to PB1 through a 220Ω resistor.
Diagram:
+3.3V ----[Potentiometer]---- GND
|
PA0 (Analog input)
STM32 LED
----------- -----
| | | |
| PB1 ---|---|>|---+---- GND
| (PWM Pin) | (Anode) (Cathode)
| |
The analog input from PA0 (A0) is read, and its value is mapped to control the brightness of an LED using PWM on PB1.
created 2024
by Liang
*/
const int potPin = PA0; // Potentiometer connected to PA0 (A0) for ADC
const int ledPin = PB1; // LED connected to PB1 (PWM-capable pin)
void setup() {
// Initialize serial communication for debugging
Serial.begin(9600);
// Configure the LED pin as an output
pinMode(ledPin, OUTPUT);
}
void loop() {
// Read the analog input from PA0 (12-bit resolution, values between 0 and 4095)
int analogInputVal = analogRead(potPin);
// Map the analog input (0-4095) to the PWM range (0-255)
int brightness = map(analogInputVal, 0, 4095, 0, 255);
// Print the raw analog input value to the Serial Monitor for debugging
Serial.print("Analog Input Value: ");
Serial.println(analogInputVal);
// Print the mapped brightness value to the Serial Monitor for debugging
Serial.print("LED Brightness Value: ");
Serial.println(brightness);
// Write the mapped brightness to the LED using PWM on PB1
analogWrite(ledPin, brightness); // analogWrite() works with PWM on STM32duino
}
ESP32-DevKitC
/*
ESP32 ADC with PWM LED Control
This code reads the analog value from a potentiometer or analog sensor connected to GPIO32 (ADC1_4) on the ESP32 and
converts it into a PWM signal that controls the brightness of an LED connected to GPIO15 using PWM.
Circuit:
- Analog input (e.g., potentiometer) connected to GPIO32 (ADC1_4).
- One side of the potentiometer connected to 3.3V, the other side connected to GND.
- Middle pin of the potentiometer connected to GPIO32.
- LED connected to GPIO15 through a 220Ω resistor.
Diagram:
+3.3V ----[Potentiometer]---- GND
|
GPIO32 (ADC input)
ESP32 LED
----------- -----
| | | |
| 15 ---|---|>|---+---- GND
| (PWM Pin) | (Anode) (Cathode)
| |
The analog input from GPIO32 is read, and its value is mapped to control the brightness of an LED using PWM on GPIO15.
created 2024
by Liang
*/
const int potPin = 32; // Potentiometer connected to GPIO32 (ADC1_4)
const int ledPin = 15; // LED connected to GPIO15 (PWM-capable pin)
void setup() {
// Initialize serial communication for debugging
Serial.begin(9600);
// Configure the LED pin as an output
pinMode(ledPin, OUTPUT);
}
void loop() {
// Read the analog input from GPIO32 (12-bit resolution, values between 0 and 4095)
int analogInputVal = analogRead(potPin);
// Map the analog input (0-4095) to the PWM range (0-255)
int brightness = map(analogInputVal, 0, 4095, 0, 255);
// Print the raw analog input value to the Serial Monitor for debugging
Serial.print("Analog Input Value: ");
Serial.println(analogInputVal);
// Print the mapped brightness value to the Serial Monitor for debugging
Serial.print("LED Brightness Value: ");
Serial.println(brightness);
// Write the mapped brightness to the LED using PWM on GPIO15
ledcWrite(0, brightness); // PWM on channel 0 with brightness value
}
MicroPython API
ESP32-DevKitC
"""
模拟输入控制PWM LED亮度
此代码从连接到引脚A5（在MicroPython中对应34号引脚，下面会进行引脚设置）的模拟输入（例如电位器）读取模拟值，
并将其转换为PWM信号，用于控制连接到引脚13的LED的亮度。
电路连接说明：
- 模拟输入（例如电位器）连接到A5（对应ESP32的34号引脚）。电位器一端接5V，另一端接地，中间引脚连接到A5作为模拟输入。
- LED通过一个220Ω电阻连接到引脚13。
示意图如下：
+5V ----[Potentiometer]---- GND
|
A5 (Analog input，对应ESP32的34号引脚)
ESP32 LED
----------- -----
| | | |
| 13 --|----|>|---+---- GND
| (PWM Pin) | (Anode) (Cathode)
| |
模拟输入（A5对应的引脚）从电位器读取电压，并使用PWM将其转换为LED的亮度值。
创建于2024
作者：Liang
"""
from machine import Pin, ADC, PWM
import time
# 初始化模拟输入引脚对应的ADC对象，在ESP32中A5对应的引脚编号为34
adc = ADC(Pin(34))
# 设置模拟输入引脚的衰减，使得能够正确读取电位器的输入范围，这里设置为11dB衰减，适合0-3.3V输入范围
adc.atten(ADC.ATTN_11DB)
# 初始化PWM对象，用于控制LED亮度，引脚为13
pwm_led = PWM(Pin(13))
# 设置PWM的频率，这里设置为1000Hz，可根据实际情况调整
pwm_led.freq(1000)
while True:
"""
主循环，不断读取模拟输入值并根据其设置LED的亮度。
在循环中：
1. 读取电位器连接引脚（A5对应的34号引脚）的模拟输入值。
2. 将模拟输入值映射到合适的PWM占空比值范围，以控制LED亮度。
3. 输出调试信息，展示模拟输入值和对应的亮度值。
4. 根据计算出的亮度值设置LED的PWM占空比来改变亮度。
5. 适当延时，避免过于频繁操作。
"""
# 读取电位器连接引脚（A5对应的34号引脚）的模拟输入值
# read()函数返回的值范围是0 - 4095（ESP32的ADC精度是12位）
analog_input_value = adc.read()
# 将模拟输入值（范围0 - 4095）映射到PWM占空比值（范围0 - 1023），以便控制LED亮度
# 这里通过简单的线性映射来转换范围，与Arduino中map函数功能类似
brightness_value = int(analog_input_value / 4095 * 1023)
# 打印原始模拟输入值到终端用于调试（可以通过串口工具查看输出）
print("Analog Input Value:", analog_input_value)
# 打印映射后的亮度值到终端用于调试
print("LED Brightness Value:", brightness_value)
# 设置LED的亮度，通过写入映射后的PWM占空比值到引脚13
pwm_led.duty(brightness_value)
# 适当延时，避免过于频繁读取和更新，这里延时100毫秒，可以根据实际情况调整
time.sleep(0.1)