LF: I2C Routine Port...Anyone up to it?

[Prev][Next][Index][Thread]

LF: I2C Routine Port...Anyone up to it?

Does anyone want to try and port Per Finander's ZShell I2C routines to
68k/Fargo? I don't know Z80 asm, and my 68k asm is weak, so I really
don't know where to start. There are many cool things for I2C, such a
temperate sensor (oh wow, now I have a $200 thermometer!), EEPROMs, IR
devices, etc... I would like to design hardware, but I need software
too! <g> Well, thanks!


-Tim


BTW, here's the code, it's not too long.




       ; ------------------------------------------ 
       ;          2
       ;         I C routines for ZShell 4.0
       ;
       ;             Per Finander, 1996  
       ;        e-mail: pfimdt93@tufvan.hv.se
       ;
       ;                   +--------
       ;        /-- --- ---| 
       ;       <           | To TI85
       ;        \-- --- ---|
       ;         |   |   | +--------
       ;         |   |   |
       ;        SDA SCL Gnd
       ;
       ; ------------------------------------------


       ; (updated 31 May 1996)
        
                ;
                ; Send I2C Start pulse
                ;


I2CStart:       ld    a,$C0    ; SDA 1 ""\
                CALL_(I2CDT)   ;     0    \_____
                ld    a,$C4
                CALL_(I2CDT)   ; SCL 1 """""\
                jr   I2CDT     ;     0       \__


                ;
                ; Send I2C Stop pulse
                ;


I2CStop:        ld    a,$CC    ; SDA 1       /""
                CALL_(I2CDT)   ;     0 _____/
                CALL_(I2CDT)
                ld    a,$C0    ; SCL 1    /"""""
                jr    I2CDT    ;     0 __/




                ; Send A to I2C bus
                ;
                ; In : A   - Byte to send
                ; Out: CF  - =1 if no acknowledge was returned (error)




I2CSend:        push  bc
                ld    b,$08
I2CNextB:       rlca
                push  af
                ld    a,$CC
                jr    nc,I2CNotS
                xor   $04
I2CNotS:        CALL_(I2CPulse)
                pop   af
                djnz  I2CNextB
                ld    a,$C8
                CALL_(I2CPulse)
                rr    c
                pop   bc
                ret




                ; Read byte from I2C bus, Send an acknowledge
                ;
                ; Out: A  = byte




I2CReadA:       ld    a,$CC
                jr    I2CRead1


                ; Read byte from I2C bus, Don't send an acknowledge
                ;
                ; Out: A  = byte


I2CRead:        ld    a,$C8
I2CRead1:       push  bc
                push  af
                ld    b,$08
                xor   a
I2CGetB:        push  af
                ld    a,$C8
                CALL_(I2CPulse)
                pop   af
                rr    c
                rla
                djnz  I2CGetB
                ld    b,a
                pop   af
                CALL_(I2CPulse)
                ld    a,b
                pop   bc
                ret


I2CPulse:       CALL_(I2CDT)
                CALL_(I2CDT)
                ld    c,$07
                in    c,(c)
I2CDT:          out  ($07),a
                xor   $08
                ret




<pre>
--
Tim Gerla    |   timg@climax.polaristel.net
Tyball@irc   |   www.geocities.com/SiliconValley/Park/1691
Tyball Dragon|   -==<UDIC>==-
Fargo Program Archive: www.geocities.com/SiliconValley/Park/1691/ti.html
</pre>