' -----[ Title ]-----------------------------------------------------------

' File...... DIOJR.PBP for microEngineering Labs PicBasic Pro compiler v2.12+
' Purpose... DIO-Link clone module
' Author.... Michel Clavette
' E-mail.... Clavette.Michel@videotron.ca
' URL....... http://pages.infinit.net/clavette/hcs.html
' Started... 29 APR 1998
' Updated... 
' License... Copyright (C) 2001 Michel Clavette
'
'  			 This program is free software; you can redistribute it and/or
'  			 modify it under the terms of the GNU General Public License
'   		 as published by the Free Software Foundation; either version 2
'    		 of the License, or (at your option) any later version.
'
'		     This program is distributed in the hope that it will be useful,
'   		 but WITHOUT ANY WARRANTY; without even the implied warranty of
'			 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
'			 GNU General Public License for more details.
'
'			 You should have received a copy of the GNU General Public
' 			 License along with this program; If not, write to the Free Software
' 			 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
'  			 02111-1307, USA.
'
' -----[ Program Description ]---------------------------------------------

' This program will act as a DIO-Link designed to interface to the Circuit Cellar Inc HCS II
' home automation system using an RS-485 network.

' Connections:
'               PIC16C84
'             -----\_/-----
'  HEARTBEAT -| RA2   RA1 |- RS-485 SERIAL I/O (pin 1 and 4 of 75176 chip)
'     STROBE -| RA3   RA0 |- RS-485 TX ENABLE (pin 2 and 3 of 75176 chip)
' Mod. reset -| RA4  OSC1 |- CRYSTAL
'  +5V via R -| /MCL OSC2 |- CRYSTAL
'        GND -| Vss   Vdd |- +5V
' I/O bit 0  -| RB0   RB7 |- I/O bit 7
' I/O bit 1  -| RB1   RB6 |- I/O bit 6
' I/O bit 2  -| RB2   RB5 |- I/O bit 5
' I/O bit 3  -| RB3   RB4 |- I/O bit 4
'             -------------


' -----[ Revision History ]------------------------------------------------


' -----[ Includes ]--------------------------------------------------------


' -----[ Constants ]-------------------------------------------------------

SIO     CON     8	'PORTA.0: serial I/O
TX	CON	9	'PORTA.1: TX enable: sets pin 1 to 1 for transmit and 0 for receive
HrtBt	CON	10	'PORTA.2: Heartbeat LED
Strobe	CON	11	'PORTA.3: Strobe line used to signal new data available on PORTB
ModRes	CON	12	'PORTA.4: If high, restore module address in EEPROM to default value "0" 


' -----[ Variables ]-------------------------------------------------------

address		VAR	BYTE[5]	'Address of the DIO module (0-7) saved into byte 0 of the EEPROM
packet		VAR	BYTE[13]'Buffer used for command input
checksum 	VAR	BYTE	'Packet checksum 
i		VAR	BYTE	'Temporary value variables
j		VAR	BYTE

' -----[ EEPROM Data ]-----------------------------------------------------

Data @0,"DIO0"		'Default DIO module address stored in EEPROM location 0


' -----[ Initialization ]--------------------------------------------------

Reset:	'Module initialization routine, execute at startup and on reset

	Clear		'Clear all variables
	OPTION_REG = $7f
	For i = 0 TO 3
		Read i,address[i]	'Read module address (0-7) from EEPROM locations 0 to 3
	Next i
	Low TX
	High Strobe


' -----[ Main Code ]-------------------------------------------------------

ReceivePacket:	'Wait here for network packet starting with the module address (DIO0-DIO7)

	Low HrtBt
	SerIn2 SIO,84,[WAIT("#"),HEX 2 checksum,skip 1, STR packet/10/13]	'Input command line
	High HrtBt


ValidateNodeID:	'Check to see if incomming packet is for this node

	For i = 0 to 3
		IF packet[i] != address[i] Then ReceivePacket
	Next i

	
ValidateChecksum:	'Check if received packet is valid

	--------> add code here!

	
ProcessCommand:

	IF packet[5] = "A" Then DIOAddress
	IF packet[5] = "Q" Then DIOQuery
	IF packet[5] = "R" Then Reset
	IF packet[5] = "S" Then DIOSet

	GoTo ReceivePacket		' Go back to serial input


SendReply:	'Send reply packet

	High TX: Pause 50
	SerOut2 SIO,84,["$",HEX 2 checksum,address," ",i,13]
	Low TX
	GoTo ReceivePacket


	End

 
' -----[ Subroutines ]-----------------------------------------------------


' Command routines


DIOAddress:	'Action: Receive 4 hexadecimal characters node ID and save to EEPROM
		'Reply: Blink heartbeat LED

	For i = 0 TO 3
		Write i,packet[i + 8]	'Save received address in EEPROM byte 0 to 3
	Next i

	For i = 1 TO 10	'Blink heartbeat LED to confim the change
		Toggle Pulse
		Pause 250
	Next i

	GoTo Reset		'Reinitialize the module


DIOQuery:	'Action: Get I/O data as per configuration
		'Reply: Return as shown on AM manual page 14

	i = PORTB	'Read the pin states of PORTB
'	IF i = %00000001 THEN
'		LOW STROBE
'		PAUSE 1000
'		HIGH STROBE
'	ENDIF

	GoTo SendReply


DIOSet:		'Action: Receive 1 hex byte and set the digital outputs to requested value
		'Reply: None

	Toggle Pulse
	GoTo ReceivePacket



' Checksum routines


Checksum:	'Packet checksum routine

	h0 = 416 + b0 + b1 + Address	'Add-up all the ASCII values of the packet to be sent,
	h0 = -h0			'Then take the two's complement

Convert:	'HEX conversion routine


	H1 = (H0 & %00001111) + 48	'Mask off the last four bits of H0, add 48 to bring us
					'into the ASCII digits "0-9" range and save it to H1
	H0 = (H0 >> 4) + 48		'Shift the content of H0 four bits to the right
					'(incoming bits are 0), add 48 to bring us into
					'the ASCII digits "0-9" range and save back into H0
	IF H1 > 57 Then			'If value is greater than "9" (in ASCII)
		H1 = H1 + 7		'Then add 7 to bring us into the "A-F" range
	EndIF
	IF H0 > 57 Then			'Ditto for H0
		H0 = H0 + 7
	EndIF
	Return