GPIO

• Functions
  • pinMode
  • digitalRead
  • digitalWrite
  • analogRead
  • dacWrite
  • Ledc
    • ledcSetup
    • ledcAttachPin
    • ledcWrite
    • ledcDetachPin
    • ledcRead
    • ledcReadFreq
  • ADC
    • adcAttachPin
    • adcStart
    • adcBusy
    • adcEnd
    • analogReadResolution
    • analogSetAttenuation
    • analogSetCycles
    • analogSetPinAttenuation
    • analogSetSamples
    • analogSetWidth
    • attachInterrupt
    • detachInterrupt
  • hallRead

*Refer to the Arduino API of Arduino *

M5STACK Pin Arrangement:

pinMode

Function:

Set pin input/output mode.

Syntax:

void pinMode(uint8_t pin, uint8_t mode);

up. Ensure correct operation as there is a risk of damage.

Example:

#include <M5Stack.h>

void setup() {
    M5.begin();
    M5.Power.begin();
    pinMode(16, OUTPUT);
}
void loop() {
}

digitalRead

Function:

Read the state of a pin.

Syntax:

int digitalRead(uint8_t pin);

Return Value:

Pin input state (0/1)

Example:

#include <M5Stack.h>

void setup() {
    M5.begin();
    M5.Power.begin();
    M5.Lcd.setTextSize(2);
}
void loop() {
    M5.Lcd.printf("Read value:%d\n", digitalRead(39));
    delay(500);
}

digitalWrite

Function:

Write a value to a pin.

Syntax:

void digitalWrite(uint8_t pin, uint8_t val);

Example:

#include <M5Stack.h>

void setup() {
    M5.begin();
    M5.Power.begin();
    M5.Lcd.setTextSize(2);
    pinMode(16, OUTPUT);
}
void loop() {
    M5.update();
    M5.Lcd.printf("Read value:%d\n", digitalRead(16));
    delay(500);
}

analogRead

Function:

Read the value of an analog pin.

Syntax:

uint16_t analogRead(uint8_t pin);

Return Value:

The read result's maximum value is determined by analogSetWidth().

Example:

#include <M5Stack.h>

void setup() {
    M5.begin();
    M5.Power.begin();
    M5.Lcd.setTextSize(2);
}
void loop() {
    M5.Lcd.printf("Read value:%d\n", analogRead(35));
    delay(500);
}

dacWrite

Function:

DAC output to specified pin.

Syntax:

void dacWrite(uint8_t pin, uint8_t value);

Example:

#include <M5Stack.h>

void setup() {
    M5.begin();
    M5.Power.begin();
    M5.Lcd.setTextSize(2);
    pinMode(25, OUTPUT);
}
void loop() {
    dacWrite(25,0x40);
    delay(500);
}

ledcSetup

Function:

Set duty cycle output.

Syntax:

double ledcSetup(uint8_t channel, double freq, uint8_t resolution_bits);

Return Value:

Actual output frequency

ledcAttachPin

Function:

Bind pin to specified ledc channel.

Syntax:

void ledcAttachPin(uint8_t pin, uint8_t channel);

ledcWrite

Function:

Output with specified duty cycle value.

Syntax:

void ledcWrite(uint8_t channel, uint32_t duty);

8_t | Channel (0～15) | | duty | uint32_t | Duty |

Example:

#include <M5Stack.h>

uint8_t pin = 25;  // Set output pin number

void setup() {
    M5.begin();
    M5.Power.begin();
    double f = ledcSetup(1, 1000, 10);  // Use ledc channel 1, set the frequency to 1kHz and the resolution to 10 bits
    Serial.printf("F=%.0f\n",f);  // print the actual setting frequency
    ledcAttachPin(pin,1);  // Bind the pin to ledc channel 1
    ledcWrite(1, 511);  // Set the duty cycle of ledc channel to 512/1024=50%
}

void loop() {
    delay(100);
}

ledcDetachPin

Function:

Release the specified port and stop output.

Syntax:

void ledcDetachPin(uint8_t pin);

Example:

#include <M5Stack.h>

uint8_t pin = 25;  // Set output pin number

void setup() {
    M5.begin();
    M5.Power.begin();
    double f = ledcSetup(1, 1000, 10);  // Use ledc channel 1, set the frequency to 1kHz and the resolution to 10 bits
    Serial.printf("F=%.0f\n",f);  // print the actual setting frequency
    ledcAttachPin(pin,1);  // Bind the pin to ledc channel 1
    ledcWrite(1, 511);  // Set the duty cycle of ledc channel to 512/1024=50%
    ledcDetachPin(pin);  // Stop the pin output
}

void loop() {
    delay(100);
}

ledcRead

Function:

Return the duty cycle of the specified channel.

Syntax:

uint32_t ledcRead(uint8_t channel)

Return Value:

Duty cycle

Example:

#include <M5Stack.h>

uint8_t pin = 25;  // Set output pin number

void setup() {
    M5.begin();
    M5.Power.begin();
    double f = ledcSetup(1, 1000, 10);  // Use ledc channel 1, set the frequency to 1kHz and the resolution to 10 bits
    Serial.printf("F=%.0f\n",f);  // print the actual setting frequency
    ledcAttachPin(pin,1);  // Bind the pin to ledc channel 1
    ledcWrite(1, 511);  // Set the duty cycle of ledc channel to 512/1024=50%
    M5.Lcd.printf("ledcRead:%d\n", ledcRead(1));  // print the actual duty cycle
}

void loop() {
    delay(100);
}

ledcReadFreq

Function:

Return the frequency of the current channel.

Syntax:

double ledcReadFreq(uint8_t channel)

Return Value:

Channel frequency

Example:

#include <M5Stack.h>

uint8_t pin = 25;  // Set output pin number

void setup() {
    M5.begin();
    M5.Power.begin();
    double f = ledcSetup(1, 1000, 10);  // Use ledc channel 1, set the frequency to 1kHz and the resolution to 10 bits
    Serial.printf("F=%.0f\n",f);  // print the actual setting frequency
    ledcAttach Pin(pin,1);  // Bind the pin to ledc channel 1
    ledcWrite(1, 511);  // Set the duty cycle of ledc channel to 512/1024=50%
    M5.Lcd.printf("ledcRead:%d\n", ledcRead(1));  // print the actual duty cycle
}

void loop() {
    delay(1000);
    M5.Lcd.printf("ledcReadFreq:%.3f\n",ledcRead

Freq(1));  // print the actual duty cycle
}

adcAttachPin

Function:

In non-blocking mode, connect the designated pin to ADC.

Syntax:

bool adcAttachPin(uint8_t pin)

Example:

#include <M5Stack.h>

uint8_t pin = 25;  // Set output pin number

void setup() {
    M5.begin();
    M5.Power.begin();
    if (adcAttachPin(pin)) {  // Attach the pin to ADC
        M5.Lcd.printf("Pin %d attached to ADC", pin);
    };
}

void loop() {}

adcStart

Function:

In non-blocking mode, start ADC conversion.

Syntax:

bool adcStart(uint8_t pin)

Return Value:

Returns 1 if start successfully, otherwise returns 0.

adcBusy

Function:

In non-blocking mode, check if ADC conversion is in progress.

Syntax:

bool adcBusy(uint8_t pin)

adcEnd

Function:

In non-blocking mode, return the conversion result, if not converted wait until completion.

Syntax:

uint16_t adcEnd(uint8_t pin)

Return Value:

Returns the conversion result.

analogReadResolution

Function:

Set the resolution of analog data reading, values 1~16, default is 12. If between 9 and 12, it equals the set hardware resolution, otherwise, the value will be shifted.

Syntax:

void analogReadResolution(uint8_t bits)

analogSetAttenuation

Function:

Set global input attenuation for ADC, values ADC_0db, ADC_2_5db, ADC_6db, ADC_11db, default is 11db.

Syntax:

void analogSetAttenuation(adc_attenuation_t attenuation)

analogSetCycles

Function:

Set sampling cycles 1-255, default is 8.

Syntax:

void analogSetCycles(uint8_t cycles)

analogSetPinAttenuation

Function:

Set attenuation for an individual pin.

Syntax:

void analogSetPinAttenuation(uint8_t pin, adc_attenuation_t attenuation)

analogSetSamples

Function:

Set the actual sampling multiplier for a single sample, values 1-255, default is 1, the actual effect is to improve the ADC sensitivity, the sampling number is expanded by N times.

Syntax:

void analogSetSamples(uint8_t samples)

analogSetWidth

Function:

Set ADC sampling resolution 9-12, default is 12.

Syntax:

void analogSetWidth(uint8_t bits)

attachInterrupt

Function:

Set pin interrupt.

Syntax:

void attachInterrupt(pin, ISR(callback function), interrupt type/mode)

detachInterrupt

Function:

Disable specified pin interrupt.

Syntax:

void detachInterrupt(pin)

hallRead

**Function

:**

Read the Hall sensor.

Syntax:

int hallRead(void));