BASCOM, Atmega32 und ein 240*128 EA DIP240-7 Display

**RobNet** · 20.11.2011, 16:23

Hi,

um also einen Atemga8 zum Portexpander als TWI Slave zu machen, könnte ich doch die Beispielrotine aus der Bascom Hilfe nutzen:

Code:

 $regfile="meinemega8konfiguration"' specify the  used micro
 $crystal= 8000000                                          ' used  crystal frequency
 $baud= 19200                                                ' use  baud rate
 $hwstack= 32                                                ' default  use 32 for the hardware stack
 $swstack= 10                                                ' default  use 10 for the SW stack
 $framesize= 40                                              ' default use  40 for the frame space
 
 
 ' Not all AVR chips  have TWI (hardware I2C)
 ' IMPORTANT : this  example ONLY works when you have the TWI slave library
 ' which is a  commercial add on library, not part of Bascom
 
 Print"MCS Electronics TWI-slave demo"
 
 Config Twislave =&H70 , Btr = 1 , Bitrate = 100000
 
 
 'as you might need  other interrupts as well, you need to enable them manual
 
 EnableInterrupts
 
 'this is just an  empty loop but you could perform other tasks there
 Do
 nop
 Loop
 End
 
 'A master can send  or receive bytes.
 'A master protocol  can also send some bytes, then receive some bytes
 'The master and  slave must  match.
 
 'the following  labels are called from the library
 Twi_stop_rstart_received:
 Print"Master sent stop or repeated  start"
 Return
 
 
 Twi_addressed_goread:
 Print"We were addressed and master  will send data"
 Return
 
 
 Twi_addressed_gowrite:
 Print"We were addressed and master  will read data"
 Return
 
 
 'this label is  called when the master sends data and the slave has received the  byte
 'the variable TWI  holds the received value
 Twi_gotdata:
 Print"received : "; Twi
 Return
 
 'this label is  called when the master receives data and needs a byte
 'the variable  twi_btr is a byte variable that holds the index of the needed byte
 'so when sending  multiple bytes from an array, twi_btr can be used for the index
 Twi_master_needs_byte:
 Print"Master needs byte :  "; Twi_btr
  Twi = 65                                                  ' twi must  be filled with a value
 Return
 
 
 'when the mast has  all bytes received this label will be called
 Twi_master_need_nomore_byte:
 Print"Master does not need anymore  bytes"
 Return

Damit wäre dann mein Mega8 als Slave konfiguriert wenn ich das richtgi verstehe. Und in der Variable TWI ist mein Empfengener Wert.

Die Bascom-Hilfe schreibt:

' IMPORTANT : this example ONLY works when you have the TWI slave library
' which is a commercial add on library, not part of Bascom

Weiß jemand was es damit auf sich hat?

Meinem Mega32 als Sender und Master würde dann so folgenden COde bekommen (ebenfalls aus der Hilfe):

Code:

Config Sda = Portb.5
 Config Scl = Portb.7
 Dim X AsByte, A AsByte, Bytes AsByte
 X = 5                                                        'assign variable to  5
 Dim Ax(10)asByte
 Const Slave =&H40                                          'slave address  of a PCF 8574 I/O IC
 I2csend Slave , X                                            'send the value  or
 
 
 For A = 1 To 10
  Ax(a)= A                                                  'Fill  dataspace
 Next
 Bytes = 10

 I2csend Slave , Ax(1), Bytes
 End

Habe ich das richtig verstanden, dass das schon meine Antwort auf die Portexpanderung wäre? Meinem Salve würde ich natürlich dann noch in ner Schleife sagen was er mit den empfangenen Daten machen soll also z.B.

Code: