'*****************************************************************
'*  Name    : xport_hello.pbp                                    *
'*  Author  : Patrick Dwyer                                      *
'*  Notice  : Copyright (c) 2006                                 *
'*          : Licensed under GPL                                 *
'*          : http://www.opensource.org/licenses/gpl-license.php *
'*  Date    : 2/14/2006                                          *
'*  Version : 1.0                                                *
'*  Notes   :                                                    *
'*          :                                                    *
'*****************************************************************

' We are using a 20Mhz oscillator
DEFINE OSC 20

DEFINE ADC_BITS 10
DEFINE ADC_CLOCK 3
DEFINE ADC_SAMPLEUS 50

potPin VAR PORTA.0
TRISA = 255
ADCON1 = %10000010

outByte VAR BYTE
outByte = 0
potVal VAR WORD
potVal = 0

' We communicate with the XPort using 9600 8N1 serial
true9600 con 84

' Our serial communication pins
tx var PORTC.6
rx var PORTC.7

' Our blinking pin for status messages
statusPin var PORTC.4
OUTPUT statusPin

' Used to read response from the XPort
inByte var byte

' Track whether or not we are connected to the remote server
connected var bit
connected = 0

' Turn on our LED so we know that the startup sequence is going
high statusPin

' Wait for the XPort to boot up
pause 5000

' Turn off the status LED while operating
LOW statusPin

' Just so we know that we're ready, we'll quickly blink the status LED
counter var byte
counter = 0
while counter < 4
    high statusPin
    pause 100
    low statusPin
    pause 100
    counter = counter + 1
wend

' In our main loop we need to accomplish the following:
'        1. Connect to the remote server
'        2. Send data to the remote server
'        3. Pause so we don't continually send data
' We use the xport_connect method to establish our connection,
' and the http_request method to send our data to a remote script
main:

    ADCIN potPin, potVal
    outByte = potVal / 4
    
    if connected = 1 then
        ' If we're already connected then we can send our message
        gosub http_request
        
        ' back off the server for a few seconds
        pause 1000    
    else
    
        ' try and connect
        gosub xport_connect
        
    endif
    
goto main

xport_connect:
    
    ' Send our connection string to the XPort. This string contains
    ' the remote IP and the remote port. In this case we're connecting
    ' to itp.nyu.edu on port 80 (HTTP)
    serout2 tx, true9600, ["C128.122.253.189/80", 10]
    
    ' now we're connected
    connected = 1
return

http_request:

    ' light LED to indicate HTTP GET request in progress:
    high statusPin

    ' To send data to the server we need to create a valid HTTP request
    ' header. All of the data we transmit here will go to the remote
    ' server.
    ' The first line tells the server that we want to get a certain
    ' page, and includes the url parameters that we want to pass to
    ' our script.
    ' The second line tells the remote server what format the header
    ' we're sending is in.
    ' The third line tells the server that the domain we want to be
    ' talking too is digilutionary.com
    ' The next line identifies what type of device is requesting data.
    ' Finally we send two newline characters, which tells the server that
    ' our request header is finished, at which point it runs our remote script
    SEROUT2 TX, true9600, ["GET /~jh1725/cgi-bin/write.py?user=jeff&msg=",DEC outByte]
    serout2 tx, true9600, [" HTTP/1.1", 10]
    SEROUT2 tx, true9600, ["HOST: itp.nyu.edu", 10]
    SEROUT2 tx, true9600, ["User-Agent: Mozilla/4.0(compatible;MSIE 5.23;Mac_PowerPC)"]
    serout2 tx, true9600, [10, 10]
    
    ' wait for bytes from server:
    ' Our server sends a 0 to finish
    while inByte <> 0
        serin2 rx, true9600, [inByte]
    wend
    
    ' now we're disconnected:
    connected = 0
    
    ' turn off LED, since GET request is complete:
    low statusPin
    
return