- Mon Jul 27, 2015 4:34 am
#24362
Does ESP8266 support internal pull-up resistors so that one need not connect external pull-up resistors when using i2c devices?
- Mon Jul 27, 2015 8:14 am
#24378
Apparently yes. See section 3.1.1 of this document.
http://bbs.espressif.com/download/file.php?id=520
http://bbs.espressif.com/download/file.php?id=520
Free ESP8266 book available for download here.
- Mon Jul 27, 2015 8:21 am
#24379
The specs don't mentioned what are the values of those internal pull-ups.
In other products, they are often "weak" pullups, something between 47K to 100K, enough for normal GPIOs, but for an I2C bus, this is not enough. So, it is better to have external ones around 4K7.
In other products, they are often "weak" pullups, something between 47K to 100K, enough for normal GPIOs, but for an I2C bus, this is not enough. So, it is better to have external ones around 4K7.
