' ****************************************************************
' * File:  uk_k51ppi.pbas  -  Ver. 1.1                           *
' * Compiler:  mikroBasic for PIC by mikroElektronica            *
' * IDE: mikroBasic for PIC by mikroElektronica                  *
' * Compiler Version: 1.1.5.0                                    *
' * Boards: GMM 4620 + GMB HR168 + K51-AVR                       *
' *   GRIFO(R)   via Dell'Artigiano 8/6                          *
' *   40016 S. Giorgio di Piano (BO)                             *
' *   Tel. +39 051 892052                   Fax. +39 051 893661  *
' *   http://www.grifo.com                  http://www.grifo.it  *
' * by Graziano Gaiba                              25.02.05      *
' ****************************************************************
'
' This demo allows to drive an I2C BUS peripheral on board of K51-AVR, PCF8574,
' through mini-BLOCK module GMB HR168 and grifo(r) mini module.
' PCF 8574 is an I/O expander that allows to drive 8 TTL digital lines, both as
' input and as output, all the operations of read and write are performed
' through synchronous serial interface I2C BUS.
' This demo acquire the status of eight TTL digital lines, and shows it on the
' 7 segments display of K51-AVR, near the characters 'in'.
'
'
' Rel 1.1 - by Graziano Gaiba
' Demo program to use PCF 8574 on board of K51-AVR using a GMB HR168
' driven by Mini Module GMM 4620
'
'
' ******************** Compiler definitions **********************
'
program uk_k51ppi
'
' ******************* Constants declaration **********************
'
const Saa1064 = $38                 ' Slave address SAA1064
const Wsaa1064 = $70                ' Slave address SAA1064 in Write
const Rsaa1064 = $71                ' Slave address SAA1064 in Read
'****************** Addresses list for Saa1064 *************************
const Ctb = 0                       ' Address Control byte
const Dig1 = 1                      ' Address Digit 1
const Dig2 = 2                      ' Address Digit 2
const Dig3 = 3                      ' Address Digit 3
const Dig4 = 4                      ' Address Digit 4
'
' **********************************************************************
'
'const Pcf8574 = $3C                 ' Slave address PCF8574A
'const Wpcf8574 = $78                ' Slave address PCF8574A in Write
'const Rpcf8574 = $79                ' Slave address PCF8574A in Read

const Pcf8574 = $24                 ' Slave address PCF8574P
const Wpcf8574 = $48                ' Slave address PCF8574P in Write
const Rpcf8574 = $49                ' Slave address PCF8574P in Read
'
'
' ******************** Variables declaration *********************
'
' Generic variables
dim d_in as byte
'
' Used by I2C BUS hardware management
dim i2c_buffer as byte[10]
'
'
' **************** Procedures definition ******************
'
'
' CPU and signals directions initialization
sub procedure Init_cpu
    '
    ADCON1=$0f        ' Imposta come I/O digitale i pin AN0..12
    CMCON=$07         ' Imposta come I/O digitale RA0..4
' Optocoupled Inputs of CN1 are:
' IN1-1 <-> RA0
' IN2-1 <-> RA1
' IN3-1 <-> RB0
' IN4-1 <-> RB1
' IN5-1 <-> RA4
' IN6-1 <-> RC0
' IN7-1 <-> RC1
' IN8-1 <-> RC5
    trisa.0=1
    trisa.1=1
    trisa.4=1
    trisb.0=1
    trisb.1=1
    trisc.0=1
    trisc.1=1
    trisc.5=1
' Optocoupled Inputs of CN2 are:
' IN1-2 <-> RD0
' IN2-2 <-> RD1
' IN3-2 <-> RD2
' IN4-2 <-> RD3
' IN5-2 <-> RD4
' IN6-2 <-> RD5
' IN7-2 <-> RD6
' IN8-2 <-> RD7
    trisd=$ff
' Relay outputs of CN3 are:
' OUT A1 <-> RB4
' OUT A2 <-> RB5
' OUT B1 <-> RB6
' OUT B2 <-> RB7
' OUT C1 <-> RB3
' OUT C2 <-> RB2
    trisb=trisb and $03
' Relay outputs of CN4 are:
' OUT D1 <-> RA3
' OUT D2 <-> RC2 (J10 in position 3-4)
    trisa.3=0
    trisc.2=0
    ' Initialize module USART (8 bit, 19200 baud rate,
    ' no parity)
    Usart_init(19200)
end sub
'
'
' Send a string of characters to the serial port
sub procedure print_USART(dim byref txt as char[255])
    dim i as byte
    dim l as byte

    l = txt[0]
    for i = 1 to l
        USART_Write(txt[i])
    next i
end sub
'
'
' Send CR + LF
sub procedure print_CRLF
    USART_Write(10)
    USART_Write(13)
end sub
'
'
' Clear screen, sending 25 times CR + LF.
sub procedure clrscr

    dim i as byte

    for i = 0 to 24
        print_CRLF
    next i
end sub
'
'
' Asks for a key press
sub procedure wait_key
    dim c as byte

    print_usart("Press a key...")
    do
        nop
    loop until USART_Data_Ready = 1
    c = USART_Read
end sub
'
'
' Procedure to set the status of the relays on connectors CN3 and CN4.
' According to the bits of port_val, each relay is turned ON
' (contact closed) or OFF (contact open).
' Bits of port_val have this meanging:
' -- CN3
' port_val.0 drives relay OUT A1
' port_val.1 drives relay OUT A2
' port_val.2 drives relay OUT B1
' port_val.3 drives relay OUT B2
' port_val.4 drives relay OUT C1
' port_val.5 drives relay OUT C2
' -- CN4
' port_val.6 drives relay OUT D1
' port_val.7 drives relay OUT D2
'
' Each bit has the following meaning:
'   bit              Meaning
'    0    Relay turned OFF (contact open)
'    1    Relay turned ON (contact closed)
sub procedure set_relays(dim port_val as byte)
' Relays are driven in complemented logic, so port_val must be
' complemented too
    port_val=port_val xor $ff
    portb.4=port_val.0
    portb.5=port_val.1
    portb.6=port_val.2
    portb.7=port_val.3
    portb.3=port_val.4
    portb.2=port_val.5

    porta.3=port_val.6

    portc.2=port_val.7
end sub
'
'
' Initialize I2C BUS hardware
sub procedure I2CBUSInit
'
' Initialize  I2C BUS
' Configure RC3 and RC4 as inputs
    trisc.3=1
    trisc.4=1
' Enable SSP module in master I2C BUS mode, clock 50 kHz
    sspstat.6=0
    sspadd=$32
    sspcon1=$28
end sub
'
'
' Generate I2C BUS start
sub procedure I2CBUSStart
    sspcon2.0=1
    while sspcon2.0=1
    wend
    pir1.3=0
end sub
'
'
' Generate I2C BUS repeated start
sub procedure I2CBUSRepStart
    sspcon2.1=1
    while sspcon2.1=1
    wend
    pir1.3=0
end sub
'
'
' Generate I2C BUS stop
sub procedure I2CBUSStop
    sspcon2.2=1
    while sspcon2.2=1
    wend
    pir1.3=0
end sub
'
'
' Send content of variable i2c_data to I2C BUS
sub procedure I2CBUSSend(dim i2c_data as byte)
    sspbuf=i2c_data
' Wait for last operation of hardware I2C interface to complete
    while pir1.3=0
    wend
    pir1.3=0
end sub
'
'
' Read a data from I2C BUS and end subs it
sub function I2CBUSGet as byte
    sspcon2.3=1
    while sspcon2.3=1
    wend
    result=sspbuf
' Wait for last operation of hardware I2C interface to complete
    while pir1.3=0
    wend
    pir1.3=0
end sub
'
'
' Send NOT acknowledge
sub procedure I2CBUSNACK
' Send NOT acknowledge...
    sspcon2.5=1
    sspcon2.4=1
' Wait for last operation of hardware I2C interface to complete
    while pir1.3=0
    wend
    pir1.3=0
end sub
'
'
' Send acknowledge
sub procedure I2CBUSACK
' Send acknowledge...
    sspcon2.5=0
    sspcon2.4=1
' Wait for last operation of hardware I2C interface to complete
    while pir1.3=0
    wend
    pir1.3=0
end sub
'
'
' Indicates that an expected acknowledge has not been received.
sub procedure I2CBUSNotAck
    print_USART("Acknowledge not received.")
    print_crlf
' Disables I2CBUS
    sspcon1.5=0
end sub

'
'
' Read one byte from device whose slave address is indicated in variable
' i2c_slave and whose address is specified in variable i2c_addr.
' Data read is returned.
sub function I2CBUSReadByte(dim i2c_slave as byte, dim i2c_addr as byte) as byte
'
' Generates I2CBUS Start.
    i2cbusstart
' Send Slave Address
    i2cbussend(i2c_slave)
' If acknowledge not received, signal an error
    if sspcon2.6=1 then I2CBUSNotAck
    end if
' Send address
    i2cbussend(i2c_addr)
' If acknowledge not received, signal an error
    if sspcon2.6=1 then I2CBUSNotAck
    end if
' Generates repeated I2CBUS Start.
    i2cbusrepstart
' Send Slave Address for reading
    i2cbussend(i2c_slave or $01)
' If acknowledge not received, signal an error
    if sspcon2.6=1 then I2CBUSNotAck
    end if
' Get data
    result = i2cbusget
' Send NOT acknowledge.
    I2CBUSNACK
' Generate stop
    i2cbusstop
end sub
'
'
' Write one byte to device whose slave address is indicated in variable
' i2c_slave and whose address is specified in variable i2c_addr.
' Data to write must be in variable i2c_data.
sub procedure I2CBUSWriteByte(dim i2c_slave as byte, dim i2c_addr as byte,
                              dim i2c_data as byte)
'
' Generates I2CBUS Start.
    i2cbusstart
' Send Slave Address for writing
    i2cbussend(i2c_slave)
' If acknowledge not received, signal an error
    if sspcon2.6=1 then I2CBUSNotAck
    end if
' Send address
    i2cbussend(i2c_addr)
' If acknowledge not received, signal an error
    if sspcon2.6=1 then I2CBUSNotAck
    end if
' Send data
    i2cbussend(i2c_data)
' If acknowledge not received, signal an error
    if sspcon2.6=1 then I2CBUSNotAck
    end if
' Generates stop
    i2cbusstop
end sub
'
'
' Send a sequence of bytes to I2C BUS device.
' Slave address must be in variable i2c_slave.
' Data to send must be in array i2c_buffer. User may change its size by
' changing the definition of array i2c_buffer.
' Number of bytes to send must be in variable i2c_to_send. User must check
' for overflows.
sub procedure I2CBUSWrite(dim i2c_slave as byte,
                          dim byref i2c_buffer as byte[10],
                          dim i2c_to_send as byte)

    dim i2c_cnt as byte
'
' Generates I2CBUS Start.
    i2cbusstart
' Send Slave Address for writing
    i2cbussend(i2c_slave)
' If acknowledge not received, signal an error
    if sspcon2.6=1 then I2CBUSNotAck
    end if
    for i2c_cnt=0 to i2c_to_send - 1
' Send data
        i2cbussend(i2c_buffer[i2c_cnt])
' If acknowledge not received, signal an error
        if sspcon2.6=1 then I2CBUSNotAck
        end if
    next i2c_cnt
' Generate stop
    i2cbusstop
end sub
'
'
' Send a sequence of bytes then read a sequence of byte from I2C BUS device.
' Slave address must be in variable i2c_slave.
' Data to send must be in array i2c_buffer. User may change its size by
' changing the definition of array i2c_buffer.
' Data will be received in the abovce mentioned array.
' Number of bytes to send must be in variable i2c_to_send. User must check
' for overflows.
' Number of bytes to receive must be in variable i2c_to_receive. User must
' check for overflows.
sub procedure I2CBUSRead(dim i2c_slave as byte,
                         dim byref i2c_buffer as byte[10],
                         dim i2c_to_send as byte,
                         dim i2c_to_receive as byte)
    dim i2c_cnt as byte
'
' Generates I2CBUS Start.
    i2cbusstart
' Send Slave Address for writing
    i2cbussend(i2c_slave)
' If acknowledge not received, signal an error
    if sspcon2.6=1 then I2CBUSNotAck
    end if
    for i2c_cnt=0 to i2c_to_send - 1
' Send data
        i2cbussend(i2c_buffer[i2c_cnt])
' If acknowledge not received, signal an error
        if sspcon2.6=1 then I2CBUSNotAck
        end if
    next i2c_cnt
' Generate repeated I2CBUS Start.
    i2cbusrepstart
' Send Slave Address for reading
    i2cbussend(i2c_slave or $01)
' If acknowledge not received, signal an error
    if sspcon2.6=1 then I2CBUSNotAck
    end if
    for i2c_cnt=0 to i2c_to_receive - 1
' Read data
        i2c_buffer[i2c_cnt] = i2cbusget
        if i2c_cnt = i2c_to_receive - 1 then
' Send NOT acknowledge.
            I2CBUSNACK
        else
' Send acknowledge.
            I2CBUSaCK
        end if
    next i2c_cnt
' Invia lo stop
    i2cbusstop
end sub
'
'
' Initialization of K51-AVR peripherals
sub procedure K51_init

    dim dummy as byte
    '
    ' Configuration of 7 segments display controller SAA 1064
    '
    do
        I2CBUSstart
        I2CBUSSend(rsaa1064)
        dummy = I2CBUSGet
        I2CBUSNACK
        I2CBUSStop
    loop until dummy = 0
    '
    i2c_buffer[0] = ctb               ' Point to control register
    i2c_buffer[1] =  %00100111        ' bit0 =1 dynamic mode
                                      ' bit1 =1 digit 1+3 not blanked
                                      ' bit2 =1 digit 2+4 not blanked
                                      ' bit3 =0 no test segment
                                      ' bit4 =0 no 3mA segment current
                                      ' bit5 =1 6mA segment current
                                      ' bit6 =0 no 12mA segment current
                                      ' bit7 =0 indifferent
        i2c_buffer[2] = 48
        i2c_buffer[3] = 84
        i2c_buffer[4] = 0
        i2c_buffer[5] = 0
        i2cbuswrite(wsaa1064, i2c_buffer, 6)
end sub
'
'
' Converts an hexadecimal figure to its 7-segments representation
sub function DecTo7Seg(dim value as byte) as byte

    dim temp as byte

    select case value
        case 0
            temp = $3F
        case 1
            temp = $06
        case 2
            temp = $5B
        case 3
            temp = $4F
        case 4
            temp = $66
        case 5
            temp = $6D
        case 6
            temp = $7D
        case 7
            temp = $07
        case 8
            temp = $7F
        case 9
            temp = $6F
        case 10
            temp = $77
        case 11
            temp = $7C
        case 12
            temp = $39
        case 13
            temp = $5E
        case 14
            temp = $79
        case 15
            temp = $71

    end select

    Result = temp
end sub
'
'
' Splits value of variable figure in two parts:
' Nibble_h (high nibble) and Nibble_l (low nibble)
sub procedure Cifre(dim figure as byte,
                    dim byref nibble_h as byte,
                    dim byref nibble_l as byte)

        nibble_h = figure div 16
        nibble_l = figure and $0F
end sub
'
'
' Visualization of two hexadecimal figures on 7 segments display
sub procedure Vis_num(dim figure as byte)

    dim nibble_h as byte
    dim nibble_l as byte

    cifre(figure, nibble_h, nibble_l)
    nibble_h = DecTo7Seg(nibble_h)
    nibble_l = DecTo7Seg(nibble_l)
    '
    ' Send the value converted in 7 segments
    ' encoding to the driver of the 7 segments display
    i2c_buffer[0] = dig3
    i2c_buffer[1] = nibble_h
    i2c_buffer[2] = nibble_l
    i2cbuswrite(Wsaa1064, i2c_buffer, 3)
end sub
'
'************************** Main Program *******************************
'
main:
    Init_cpu
    ' Turn OFF relays
    set_relays(0)
    ' Initialize hardware I2C BUS peripheral
    i2cbusinit
    ' Initialize K51-AVR on board I2C BUS peripheral
    k51_init
    ' Clear screen
    clrscr
    print_USART("Show on the 7 segments display the status of TTL inputs of PCF 8574 on CN1...")
for_ever:
'
' Reads status of PCF 8574 TTL inputs
'
    i2cbusstart
    i2cbussend(wpcf8574)
    i2cbusrepstart
    i2cbussend(rpcf8574)
    d_in = i2cbusget
    i2cbusnack
    i2cbusstop
    ' Shows its argument in hexadecimal on the 7 segments display
    vis_num(d_in)

    goto for_ever
end.