digitalRead returns wrong values ?

[chopperaddict]

I have just started using tis library, and it is great so far writing to the chip, BUT I want to be able to read its content as well, but the following code returns 1111010 1001

uint8_t input = 0; setStartupFrogs(); Serial.println("Startup setting setup"); delay(3000); //Serial.println(expander.digitalRead(3) ? "HIGH" : "LOW"); // Print button pin state input = Serial.println(expander.read(), BIN); // Read the whole pins input register Serial.println(input, BIN); setStrartupFrogs() actually sets pins 0, 2,and 7, so I am expecting to see

10000101

assuming it maintains MSB or LSB forread and write, but these values are not correct either way around ?

Is this a known issue ?

[FernandoGarcia]

I have reported this issue before.

https://github.com/skywodd/pcf8574_arduino_library/issues/3

[francescolavra]

Serial.println() returns the number of characters written to the serial port, so when you execute input = Serial.println(expander.read(), BIN) you are assigning to the input variable the number of characters written, which equals the size of the string "1111010" plus the "\r\n" sequence, i.e. 9 characters; that's why you see 1001.

[pierrot10]

@francescocolavra, Ok than could show use how we can display in a terminal or a LCD when the pin is HIGH?

[francescolavra]

Like that: Serial.println(expander.digitalRead(myPin) ? "HIGH" : "LOW");

[pierrot10]

Dera Francesco, thank for your reply