© MCS Electronics, 1995-2007
X The hexadecimal string that must be converted.
In VB you can use the VAL() function to convert hexadecimal strings.
But since that would require an extra test for the leading &H signs that are required in VB, a separate function was designed.
See also
HEX , VAL , STR , BIN , BINVAL
Example
$regfile = "m48def.dat" |
' specify the used |
micro |
' used crystal |
$crystal = 8000000 |
frequency |
' use baud rate |
$baud = 19200 |
$hwstack = 32 |
' default use 32 |
for the hardware stack |
' default use 10 |
$swstack = 10 |
for the SW stack |
' default use 40 |
$framesize = 40 |
for the frame space |
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Config Com1 = Dummy , Synchrone = 0 , Parity = None , Stopbits = 1 , Databits = 8 , Clockpol = 0
Dim L As Long
Dim S As String * 8
Do
Input "Hex value " , S
L = Hexval(s)
Print L ; Spc(3) ; Hex(l)
Loop
HIGH
Action
Retrieves the most significant byte of a variable.
Syntax
var = HIGH( s )
Remarks
Var |
The variable that is assigned with the MSB of var S. |
S |
The source variable to get the MSB from. |
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See also
LOW , HIGHW
© MCS Electronics, 1995-2007
Example
Dim I As Integer , Z As Byte
I = &H1001
Z = High(i) ' is 10 hex or 16 dec
End
HIGHW
Action
Retrieves the most significant word of a long variable.
Syntax
var = HIGHW( s )
Remarks
Var |
The variable that is assigned with the MS word of var S. |
S |
The source variable to get the MSB from. |
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There is no LowW() function. This because when you assign a Long to a word or nteger,i only the lower part is assigned. For this reason you do not need a Loww() function. W=L will do the same.
See also
LOW , HIGH
Example
Dim X As Word , L As Long
L = &H12345678
X = Highw(l)
Print Hex(x)
HOME
Action
Place the cursor at the specified line at location 1.
Syntax
HOME UPPER | LOWER | THIRD | FOURTH
Remarks
If only HOME is used than the cursor will be set to the upper line.
You may also specify the first letter of the line like: HOME U
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© MCS Electronics, 1995-2007 |
See also |
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CLS , LOCATE |
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For a complete example see LCD |
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Partial Example |
'set cursor |
Locate 2 , 1 |
position |
'display this |
Lcd "*" |
Home Upper |
'select line 1 and |
return home |
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I2CINIT
Action
Initializes the SCL and SDA pins.
Syntax
I2CINIT
Remarks
By default the SCL and SDA pins are in the right state when you reset the chip. Both the PORT and the DDR bits are set to 0 in that case.
When you need to change the DDR and/or PORT bits you can use I2CINIT to bring the pins in the proper state again.
ASM
The I2C routines are located in i2c.lib. _i2c_init is called.
See also
I2CSEND , I2CSTART , I2CSTOP , I2CRBYTE , I2CWBYTE , I2C_TWI Library for using TWI
Example
Config Sda = Portb.5
Config Scl = Portb.7
I2cinit
Dim X As Byte , Slave As Byte |
'reset variable |
X = 0 |
Slave = &H40 |
'slave address of |
a PCF 8574 I/O IC |
'get the value |
I2creceive Slave , X |
Print X |
'print it |
© MCS Electronics, 1995-2007
I2CRECEIVE
Action
Receives data from an I2C serial slave device.
Syntax
I2CRECEIVE slave, var
I2CRECEIVE slave, var , b2W, b2R
Remarks
Slave |
A byte, Word/Integer variable or constant with the slave address |
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from the I2C-device. |
Var |
A byte or integer/word variable that will receive the information |
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from the I2C-device. |
b2W |
The number of bytes to write. |
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Be cautious not to specify too many bytes! |
b2R |
The number of bytes to receive. |
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Be cautious not to specify too many bytes! |
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You must specify the base address of the slave chip because the read/write bit is set/reset by the software.
When an error occurs, the internal ERR variable will return 1. Otherwise it wil be set to 0.
ASM
The I2C routines are located in the i2c.lib/i2c.lbx files.
See also
I2CSEND, I2CSTART , I2CSTOP, I2CRBYTE , I2CWBYTE
Example
Config Sda = Portb.5 |
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Config Scl = Portb.7 |
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Dim X As Byte , Slave As Byte |
'reset variable |
X = 0 |
Slave = &H40 |
'slave address of |
a PCF 8574 I/O IC |
'get the value |
I2creceive Slave , X |
Print X |
'print it |
Dim Buf(10)as Byte |
|
Buf(1) = 1 : Buf(2) = 2 |
'send two bytes |
I2creceive Slave , Buf(1) , 2 , 1 |
and receive one byte |
'print the |
Print Buf(1) |
received byte |
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End |
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© MCS Electronics, 1995-2007
I2CSEND
Action
Send data to an I2C-device.
Syntax
I2CSEND slave, var
I2CSEND slave, var , bytes
Remarks
Slave |
The slave address off the I2C-device. |
Var |
A byte, integer/word or numbers that holds the value, which will be, |
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send to the I2C-device. |
Bytes |
The number of bytes to send. |
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When an error occurs, the internal ERR variable will return 1. Otherwise it wil be set to 0.
ASM
The I2C routines are located in the i2c.lib/i2c.lbx files.
See also
I2CRECEIVE , I2CSTART, I2CSTOP , I2CRBYTE , I2CWBYTE
Example
Config Sda = Portb.5 |
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Config Scl = Portb.7 |
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Dim X As Byte , A As Byte , Bytes As Byte |
'assign variable |
X = 5 |
to 5 |
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Dim Ax(10)as Byte |
'slave address of |
Const Slave = &H40 |
a PCF 8574 I/O IC |
'send the value or |
I2csend Slave , X |
For A = 1 To 10 |
'Fill dataspace |
Ax(a) = A |
Next |
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Bytes = 10 |
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I2csend Slave , Ax(1) , Bytes |
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End |
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I2START,I2CSTOP, I2CRBYTE, I2CWBYTE
Action