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Микроконтроллеры ЭВМ

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BASCOM AVR, help reference (2007).PDF

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Returns the tangent of a float

Syntax

var = TAN( source )

Remarks

Var	A numeric variable that is assigned with tangent of variable source.
Source	The single or double variable to get the tangent of.

All trig functions work with radians. Use deg2rad and rad2deg to convert between radians and angles.

TCPCHECKSUM

Action

Return a TCP/IP checksum

Syntax

res= TCPCHECKSUM(buffer , bytes)

Remarks

Res	A word variable that is assigned with the TCP/IP checksumof the buffer
	page -687-
	page -687-

	© MCS Electronics, 1995-2007

Buffer	A variable or array to get the checksum of.
Bytes	The number of bytes that must be examined.

Checksum's are used a lot in communication protocols. A checksum is a way to verify that received data is the same as it was sent. In the TCP/IP protocol a special checksum is used. You can use it for the PING sample.

See also

CRC8 , CRC16, CRC32 , CHECKSUM

ASM

NONE

Example

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

'name	: PING_TWI.bas	http://www.faqs.org/rfcs/rfc792.html
'copyright	: (c) 1995-2005, MCS Electronics
'purpose	: Simple PING program
'micro	:Mega88
'suited for demo	: yes
'commercial addon needed : no
'-----------------------------------------------------------------------------------------		' specify the used micro
$regfile= "m32def.dat"		' specify the used micro

$crystal= 8000000 $baud = 19200 $hwstack= 80 $swstack= 128 $framesize = 80

Const Debug = 1

Const Sock_stream = $01

Const Sock_dgram = $02

Const Sock_ipl_raw = $03

Const Sock_macl_raw = $04

Const Sel_control = 0

Const Sel_send = 1

Const Sel_recv = 2

'socket status

Const Sock_closed = $00 Const Sock_arp = $01 Const Sock_listen = $02 Const Sock_synsent = $03

Const Sock_synsent_ack = $04 Const Sock_synrecv = $05 Const Sock_established = $06 Const Sock_close_wait = $07 Const Sock_last_ack = $08 Const Sock_fin_wait1= $09 Const Sock_fin_wait2= $0a Const Sock_closing = $0b Const Sock_time_wait = $0c Const Sock_reset = $0d Const Sock_init = $0e

Const Sock_udp = $0f

'used crystal frequency

'use baud rate

'default use 32 for the hardware stack

'default use 10 for the SW stack

'default use 40 for the frame space

'Tcp

'Udp

'Ip Layer Raw Sock

'Mac Layer Raw Sock

'Confirm Socket Status

'Confirm Tx Free Buffer Size

'Confirm Rx Data Size

'Status Of Connection Closed

'Status Of Arp

'Status Of Waiting For Tcp Connection Setup

'Status Of Setting Up Tcp Connection ' Status Of Setting Up Tcp Connection

'Status Of Setting Up Tcp Connection

'Status Of Tcp Connection Established

'Status Of Closing Tcp Connection

'Status Of Socket Initialization

'Status Of Udp

page -688-

	© MCS Electronics, 1995-2007
Const Sock_raw = $10	' Status of IP RAW
'we do the usual	' display a message
Print"Init TCP"
EnableInterrupts	' before we use config tcpip , we need to enable the interrupts
Config Tcpip = Int0, Mac = 12.128.12.34.56.78 ,Ip= 192.168.0.8 , Submask = 255.255.255.0 , Gateway
= 192.168.0.1 ,Localport = 1000 ,Tx= $55 ,Rx = $55 ,Twi= &H80 ,Clock = 400000
Print"Init done"

Dim Peersize As Integer, Peeraddress As Long ,Peerport As Word

Dim IdxAs Byte,Result As Word ,JAs Byte, Res As Byte

Dim IpAs Long

Dim Dta(12)As Byte, Rec(12)As Byte

Dta(1)= 8	'type is echo
Dta(2)= 0	'code
Dta(3)= 0	' for checksum initialization
Dta(4)= 0	' checksum
Dta(5)= 0	' a signature can be any number
Dta(6)= 1	' signature
Dta(7)= 0	' sequence number - any number
Dta(8)= 1
Dta(9)= 65
Dim W As Word At Dta + 2Overlay	'same as dta(3) and dta(4)
W = Tcpchecksum(dta(1),9)	' calculate checksum and store in dta(3) and dta(4)
#ifDebug
For J= 1To 9
Print Dta(j)
Next
#endif
Ip= Maketcp(192.168.0.16)	'try to check this server

Print"Socket ";Idx;"";Idx

Setipprotocol Idx,1 'set protocol to 1 'the protocol value must be set BEFORE the socket is openend

Idx= Getsocket(idx,3, 5000 ,0)

Do	'writepingdata	'
Result= Udpwrite(ip,7,Idx,Dta(1),9)	'writepingdata	'
Print Result
Waitms 100	'check for data
Result= Socketstat(idx,Sel_recv)	'check for data
Print Result
IfResult >= 11 Then
Print"Ok"	'get data with TCPREAD !!!
Res= Tcpread(idx, Rec(1),Result)	'get data with TCPREAD !!!
#ifDebug	'
Print"DATA RETURNED :";Res	'
For J= 1To Result
Print Rec(j);"";
Next
Print

page -689-

	© MCS Electronics, 1995-2007
#endif	'there might be a problem
Else	'there might be a problem
Print"Network not available"
End If
Waitms 1000
Loop

TCPREAD

Action

Reads data from an open socket connection.

Syntax

Result = TCPREAD( socket , var, bytes)

Remarks

Result A byte variable that will be assigned with 0, when no errors occurred. When an error occurs, the value will be set to 1.

	When there are not enough bytes in the reception buffer, the routine willwait
	until there is enough data or the socket is closed.
socket	The socket number you want to read data from(0-3).
Var	The name of the variable that will be assigned with the data from the socket.
Bytes	The number of bytes to read. Only valid for non-string variables.

When you use TCPread with a string variable, the routine will wait for CR + LF and it will return the data without the CR + LF.

For strings, the function will not overwrite the string.

For example, your string is 10 bytes long and the line you receive is 80 bytes long, you wil receive only the first 10 bytes after CR + LF is encountered.

Also, for string variables, you do not need to specify the number of bytes to read since the routine will wait for CR + LF.

For other data types you need to specify the number of bytes.

There will be no check on the length so specifying to receive 2 bytes for a byte will overwrite the memory location after the memory location of the byte.

$regfile = "m48def.dat"	' specify the used
micro	' used crystal
$crystal = 8000000	' used crystal
frequency	' use baud rate
$baud = 19200	' use baud rate
$hwstack = 32	' default use 32
for the hardware stack	' default use 10
$swstack = 10	' default use 10
for the SW stack	' default use 40
$framesize = 40	' default use 40
for the frame space
Config Com1 = Dummy , Synchrone = 0 , Parity = None , Stopbits = 1 , Databits
= 8 , Clockpol = 0
Dim S As Single , X As Single	' prints
S = 0.5 : X = Tan(s) : Print X	' prints
0.546302195	' prints
S = 0.5 : X = Sin(s) : Print X	' prints
0.479419108	' prints
S = 0.5 : X = Cos(s) : Print X	' prints
0.877588389
End

Result = Socketstat(idx , Sel_recv)	' get number of bytes waiting
If Result > 0 Then
Result = Tcpread(idx , S)
End If