There are lots of chips available using the I2C-protocol. These examples use the I2C implementation as described here. All of them need a specific device driver. To name some: sensors, memory, clocks, I/O, etc. Here you can add any driver you like to share. Preferably written in Generic Forth. But as we embrace the differences, you may also add them in a new folder for your own dialect !

• 24C02, EEPROM memory, this driver works for EEPROM & FRAM chips from 1 kBit to 2 kBit datasheet & examples:
• 24CL64, EEPROM memory, this driver works for EEPROM & FRAM chips from 32 kBit to 512 kBit datasheet & examples:

      EDMP ( ea -- )       - Dump EEPROM memory from address ea
      SHOW ( -- )          - Show string stored in EEPROM

• APDS9300, Light sensor datasheet & examples:

      APDS ( -- )          - Show light and infrared light data 

• PCA9632, 4-bit LED driver datasheet & examples:

      PCA-ON ( -- )        - Activate PCA9632 LED power switch 
      >ON    ( b -- )      - (De)activate LED power output modes

• DS1307, Low power Real-Time Clock datasheet & examples:

      ALARM  ( -- )        - Give every 10 seconds text string alarm signal
      TIMER  ( s m -- )    - Give every s seconds and m minutes a text string
      CLOCK  ( -- )        - Show an RTC each second on a new line, first set the RTC!

• PCF8574, 8-bit I/O extender datasheet & examples:

      RUNNER1 ( -- )       - Running light on the output chip 
      RUNNER2 ( -- )       - Same running light with delay timing using the input chip
      SHOW    ( -- )       - Copy input chip data to output chip 

• PCF8591, 8-bit ADC/DAC (four inputs, one output) datasheet & examples:

      ANALOG  ( +n -- )    - Convert ADC input +n, output to a DAC and type on screen 

• LM75, Temperature sensor with 9-bit resolution and max. +-2 degree celcius accuracy datasheet & examples:

      TEMPERATURE2 ( -- )  - Read & show 9-bit temperature continuously

• TMP75, Temperature sensor with 12-bit resolution and max. +-1 degree celcius accuracy datasheet & examples:

      TMP75-DEMO   ( -- )  - Read & show temperature continuously

• More on OLEDs ; OLED drivers, character sets, etc.
• More on LCD's ; LCD drivers, character sets, etc.
• Scanner ; Scan your I2C network for connected devices

Using the I2C driver as presented I2C, The I2C protocol

Function: {AP-ADDR  ( reg +n -- )
  29  perform device! perform {i2c-write  or reg with 80 bus!

Function: APDS@     ( reg -- byte )
  1  perform {ap-addr perform i2c}
  perform {i2c-read  perform bus@  perform i2c}

Function: APDS!     ( byte reg -- )
  2  perform {ap-addr  perform bus!  perform i2c}

Function: APDS-ON   ( -- )     3 0   perform apds!
Function: APDS-ON   ( -- )     3 0   perform apds!
Function: LIGHT     ( -- u )   0C  do apds@  100 times  0D  do apds@  or
Function: IR        ( -- u )   0E  do apds@  100 times  0F  do apds@  or

hex
: {AP-ADDR  ( reg +n -- )   29 device!  {i2c-write  80 or bus! ;
: APDS@     ( reg -- b )    1 {ap-addr i2c}  1 {i2c-read  bus@ i2c} ;
: APDS!     ( b reg -- )    2 {ap-addr  bus! i2c} ;
: APDS-ON   ( -- )          3 0 apds! ;
: APDS-OFF  ( -- )          0 0 apds! ;
: LIGHT     ( -- u )        0C apds@  0D apds@  b+b ;
: IR        ( -- u )        0E apds@  0F apds@  b+b ;

Have a look in this directory for Generic Forth implementations. Or in the sub directories for implementations for different systems.