Lesson20- how to use PCF8574 IIC extend GPIO for ESP32 input ports

[admin]

Arduino IDE source code: 
  PCF8574-DI.zip (Size: 806 bytes / Downloads: 651)

[lonejan]

Dear admin, how did u set 26 and 29 as i2c pins? I'm stuck on settings these pins as SDA & SCL((( I found in soc_caps.h this code:

// 0~39 valid except 24, 28~31
#define SOC_GPIO_VALID_GPIO_MASK (0xFFFFFFFFFFULL & ~(0ULL | BIT24 | BIT28 | BIT29 | BIT30 | BIT31))
// GPIO >= 34 are input only
#define SOC_GPIO_VALID_OUTPUT_GPIO_MASK (SOC_GPIO_VALID_GPIO_MASK & ~(0ULL | BIT34 | BIT35 | BIT36 | BIT37 | BIT38 | BIT39))

29 pin is denied to use



pls help)

[admin]

these are i2c bus pin define for KC868-A8:
IIC SDA:4
IIC SCL:5