Bstart
Positron8 · Revision 4.0.6.5 · PDF page 122
Syntax
Bstart
Overview
Send a Start condition to the I2C bus.
Notes
Because of the subtleties involved in interfacing to some I2C devices, the compiler's standard Busin, and Busout commands were found lacking somewhat. Therefore, individual pieces of the I2C protocol may be used in association with the new structure of Busin, and Busout. See relevant sections for more information.
Example
' Interface to a 24LC32 serial EEPROM
Device = 16F1829 ' Select the device to compile for
Declare Xtal = 16 ' Tell the compiler the device will be operating at 16MHz
Declare Hserial_Baud = 9600 ' Set the Baud rate for HRsoutLn
Dim MyLoop as Byte
Dim Array[10] as Byte
'
' Transmit bytes to the I2C bus
'
Bstart ' Send a Start condition
Busout 0b10100000 ' Target an EEPROM, and send a Write command
Busout 0 ' Send the High Byte of the address
Busout 0 ' Send the Low Byte of the address
For MyLoop = 48 to 57 ' Create a loop containing ASCII 0 to 9
Busout MyLoop ' Send the value of MyLoop to the EEPROM
Next ' Close the loop
Bstop ' Send a Stop condition
DelayMs 10 ' Wait for the data to be entered into EEPROM matrix
'
' Receive bytes from the I2C bus
'
Bstart ' Send a Start condition
Busout 0b10100000 ' Target an EEPROM, and send a Write command
Busout 0 ' Send the High Byte of the address
Busout 0 ' Send the Low Byte of the address
Brestart ' Send a Restart condition
Busout 0b10100001 ' Target an EEPROM, and send a Read command
For MyLoop = 0 to 9 ' Create a loop
Array[MyLoop] = Busin ' Load an array with bytes received
If MyLoop = 9 Then Bstop : Else : BusAck ' Ack or Stop ?
Next ' Close the loop
HRsoutLn Str Array ' Display the Array as a String
StopSee also: Bstop, Brestart, BusAck, Busin, Busout, HbStart, HbRestart, HbusAck,
