I2C – LCD interface – Type 1

A range of inexpensive serial to Hitachi style LCD interfaces are becoming available.

This article describes the settings for one sold by NYplatform on eBay (about $25 for 5 inc post at the time of writing – but they are getting cheaper). It uses the Philips PCF8574T I2C expander chip which is supported by the user developed Arduino LCD Library V1.2.


Above is one of these modules soldered to a 16×2 LCD module.

The settings for this module are different to the defaults used in the library, a consequence of the way the board is wired. The only change required so that the library example code worked was the statement that creates an instance of the LiquidCrystal_I2C object:

LiquidCrystal_I2C lcd(0x20,4,5,6,0,1,2,3,7,POSITIVE);  // Set the LCD I2C address

The board has 10k pullup resistors on SDA and SCL, backlight switching and a contrast pot. The board is configurable to one of 8 addresses, 0x20-0x27 using solder shunts.

Recommended, works a treat and being I2C can share the SCL and SDA pins with other I2C devices.

See also I2C – LCD interface – Type 2.