Parallax 27911 Manual page 6

GOSUB I2C_Start
I2C_DATA = WRITE_DATA
GOSUB I2C_Write
I2C_DATA = I2C_REG
GOSUB I2C_Write
GOSUB I2C_Stop
GOSUB I2C_Start
I2C_DATA = READ_DATA
GOSUB I2C_Write
GOSUB I2C_Read
GOSUB I2C_NACK
GOSUB I2C_Stop
RETURN
I2C_Start:
LOW SDA
LOW SCL
RETURN
I2C_Stop:
LOW SDA
INPUT SCL
INPUT SDA
RETURN
I2C_ACK:
LOW SDA
INPUT SCL
LOW SCL
INPUT SDA
RETURN
I2C_NACK:
INPUT SDA
INPUT SCL
LOW SCL
RETURN
I2C_Read:
SHIFTIN SDA, SCL, MSBPRE, [I2C_DATA]
RETURN
I2C_Write:
I2C_LSB = I2C_DATA.BIT0
I2C_DATA = I2C_DATA / 2
SHIFTOUT SDA, SCL, MSBFIRST, [I2C_DATA\7]
IF I2C_LSB THEN INPUT SDA ELSE LOW SDA
INPUT SCL
LOW SCL
INPUT SDA
INPUT SCL
LOW SCL
RETURN
Note: When this program is run the BASIC Stamp Debug Terminal will automatically open.
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