Action

This verifies if an ID is available on the 1wire bus.

 

 

Syntax

1WVERIFY ar(1)

1WVERIFY ar(1) , port, pin

 

 

Remarks

 

Returns ERR set to 0 when the ID is found on the bus otherwise it will be 1.

 

 

ASM

The following asm routines are called from mcs.lib.

_1wire_Search_Next : (calls _1WIRE, _ADJUST_PIN , _ADJUST_BIT_ADDRESS)

 

 

See also

1WWRITE , 1WRESET , 1WREAD , 1WSEARCHFIRST, 1WIRECOUNT

 

 

Example

'--------------------------------------------------------------------------------

'name                     : 1wireSearch.bas

'copyright                : (c) 1995-2021, MCS Electronics

'purpose                  : demonstrates 1wsearch

'micro                    : Mega48

'suited for demo          : yes

'commercial addon needed  : no

'--------------------------------------------------------------------------------

 

$regfile = "m48def.dat"

$crystal = 4000000

 

$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

 

Config 1wire = Portb.0                   'use this pin

'On the STK200 jumper B.0 must be inserted

 

'The following internal bytes are used by the scan routines

'___1w_bitstorage , Byte used for bit storage :

'      lastdeviceflag bit 0

'      id_bit         bit 1

'      cmp_id_bit     bit 2

'      search_dir     bit 3

'___1wid_bit_number, Byte

'___1wlast_zero,  Byte

'___1wlast_discrepancy , Byte

'___1wire_data , string * 7 (8 bytes)

 

'[DIM variables used]

'we need some space from at least 8 bytes to store the ID

Dim Reg_no(8) As Byte

 

'we need a loop counter and a word/integer for counting the ID's on the bus

Dim I As Byte , W As Word

 

'Now search for the first device on the bus

Reg_no(1) = 1wsearchfirst()

 

For I = 1 To 8                                             'print the number

  Print Hex(reg_no(i));

Next

Print

 

Do

'Now search for other devices

Reg_no(1) = 1wsearchnext()

For I = 1 To 8

  Print Hex(reg_no(i));

Next

Print

Loop Until Err = 1

 

 

 

'When ERR = 1 is returned it means that no device is found anymore

'You could also count the number of devices

W = 1wirecount()

'It is IMPORTANT that the 1wirecount function returns a word/integer

'So the result variable must be of the type word or integer

'But you may assign it to a byte or long too of course

Print W

 

 

'as a bonus the next routine :

' first fill the array with an existing number

Reg_no(1) = 1wsearchfirst()

' unremark next line to chance a byte to test the ERR flag

'Reg_no(1) = 2

'now verify if the number exists

1wverify Reg_no(1)

Print Err

'err =1 when the ID passed n reg_no() does NOT exist

' optional call it with pinnumber line  1wverify reg_no(1),pinb,1

 

'As for the other 1wire statements/functions, you can provide the port and pin number as anoption

'W = 1wirecount(pinb , 1)                                    'for example look at pin PINB.1

End