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Hi!
I am trying to read inputs of PCF8575 with ESP32. I had problems reading it with Arduino IDE but I found a “solution”. If I define ALL pins as outputs, then I set them to 1 and then define them as inputs. I can read correctly the voltage changes on the inputs.
Now I load the same code with platform io and it doesnt work.
I use the same version of your library 1.1.1
Could please help me?This is my code:
#include “PCF8575.h”
PCF8575 pcf(0x20);
bool estado=0,value=0,machine_state=0;
void set_pcf();
void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
set_pcf();
machine_state=0;
// pcf.digitalWrite(10, LOW);//En cuanto cambio el estado de la salida digital el resto se quedan a 0 también.
}void loop() {
// put your main code here, to run repeatedly:
switch (machine_state)
{
case (0):
Serial.println(“CASE WAITING”);
value=pcf.digitalRead(P1);
Serial.println(value);
delay(50);
break;
}}
void set_pcf(){
pcf.pinMode(0, OUTPUT);
pcf.pinMode(1, OUTPUT);
pcf.pinMode(2, OUTPUT);
pcf.pinMode(3, OUTPUT);
pcf.pinMode(4, OUTPUT);
pcf.pinMode(5, OUTPUT);
pcf.pinMode(6, OUTPUT);
pcf.pinMode(7, OUTPUT);
pcf.pinMode(8, OUTPUT);
pcf.pinMode(9, OUTPUT);
pcf.pinMode(10, OUTPUT);
pcf.begin();
Serial.println(“RELÉ OFF”);
pcf.digitalWrite(0,HIGH);
pcf.digitalWrite(1,HIGH);
pcf.digitalWrite(2,HIGH);
pcf.digitalWrite(3,HIGH);
pcf.digitalWrite(4,HIGH);
pcf.digitalWrite(5,HIGH);
pcf.digitalWrite(6,HIGH);
pcf.digitalWrite(7,HIGH);
pcf.digitalWrite(8,HIGH);
pcf.digitalWrite(9,HIGH);
pcf.digitalWrite(10, HIGH);
pcf.pinMode(0, INPUT);
pcf.pinMode(1, INPUT);
pcf.pinMode(2, INPUT);
pcf.pinMode(3, INPUT);
pcf.pinMode(4, INPUT);
pcf.pinMode(5, INPUT);
pcf.pinMode(6, INPUT);
pcf.pinMode(7, INPUT);
pcf.pinMode(8, INPUT);
pcf.pinMode(9, INPUT);
pcf.pinMode(10, OUTPUT);
} -
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Thank you for your prompt response.
Usual code was my first code. But it doesn’t work, all entries seem to be LOW when they should be HIGH.
I have read that I am not the only one who has seen this strange behavior. In fact one user discussed with you and came to the conclusion that the solution was to declare everything as HIGH OUTPUTs and then as INPUTs. -
Hi,
I tested now this sketch/* KeyPressed on PIN1 by Mischianti Renzo <http://www.mischianti.org> https://www.mischianti.org/2019/01/02/pcf8575-i2c-digital-i-o-expander-fast-easy-usage/ */ #include "Arduino.h" #include "PCF8575.h" // Set i2c address PCF8575 pcf8575(0x20); unsigned long timeElapsed; void setup() { Serial.begin(115200); // pcf8575.pinMode(P0, OUTPUT); pcf8575.pinMode(P1, INPUT); pcf8575.begin(); timeElapsed = millis(); } void loop() { // if (millis() - timeElapsed > 2000) { // if (pcf8575.digitalRead(P0) == HIGH) { // pcf8575.digitalWrite(P0, LOW); // } else { // pcf8575.digitalWrite(P0, HIGH); // } // timeElapsed = millis(); // } uint8_t val = pcf8575.digitalRead(P1); if (val == HIGH) { Serial.println("KEY PRESSED"); } delay(100); }And this sketch
/* KeyPressed on PIN1 by Mischianti Renzo <http://www.mischianti.org> https://www.mischianti.org/2019/01/02/pcf8575-i2c-digital-i-o-expander-fast-easy-usage/ */ #include "Arduino.h" #include "PCF8575.h" // Set i2c address PCF8575 pcf8575(0x20); unsigned long timeElapsed; void setup() { Serial.begin(115200); pcf8575.pinMode(P0, OUTPUT); pcf8575.pinMode(P1, INPUT); pcf8575.begin(); timeElapsed = millis(); } void loop() { if (millis() - timeElapsed > 2000) { if (pcf8575.digitalRead(P0) == HIGH) { pcf8575.digitalWrite(P0, LOW); } else { pcf8575.digitalWrite(P0, HIGH); } timeElapsed = millis(); } uint8_t val = pcf8575.digitalRead(P1); if (val == HIGH) { Serial.println("KEY PRESSED"); } delay(100); }and work properly.
Can you also insert the wiring diagram?
Bye Renzo
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