# #############################################################################
#
# Copyright (c) 1999-2001 by Wayne C. Gramlich.
# All rights reserved.
#
# Permission to use, copy, modify, distribute, and sell this software
# for any purpose is hereby granted without fee provided that the above
# copyright notice and this permission are retained.  The author makes
# no representations about the suitability of this software for any purpose.
# It is provided "as is" without express or implied warranty.
#
# This is a test harness for testing the LED10 RoboBrick.  See:
#
#   http://web.gramlich.net/projects/robobricks/led10/index.html
#
# for more details.
#
# #############################################################################

processor pic16f84 cp=off dp=off pwrte=disabled wdte=disabled fosc=xt
constant clock_rate 4000000
constant instruction_rate clock_rate / 4
constant baud_rate 2400
constant instructions_per_bit instruction_rate / baud_rate
constant delays_per_bit 3
constant instructions_per_delay instructions_per_bit / delays_per_bit

# The null pulse that comes back from a clock pulse command is supposed to be
# 9 bits long.  At 4Mhz = 1 instruction per microsecond, 9 bits is 9/2400 =
# 3.75ms.  The count loop below is 7 instruction long.  3.75/.007 = 536 = 0x217.
# So we want our timer loop to get as close to 0x217 as possible.
constant clock_fudge 4
constant clock_target 0x17 + clock_fudge

constant sp 32
constant cr 13
constant lf 10

# Some bit definitions:
constant rx_slave_bit 0
constant tx_slave_bit 1
constant tx_master_bit 2
constant rx_master_bit 3
constant rx_slave_mask 1 << rx_slave_bit
constant tx_slave_mask 1 << tx_slave_bit
constant rx_master_mask 1 << rx_master_bit
constant tx_master_mask 1 << tx_master_bit

register status 3
bind c status@0
bind z status@2

port porta a bits_only read_write_static
pin tx_master_pin porta tx_master_bit write_only
pin rx_master_pin porta rx_master_bit read_only
pin tx_slave_pin porta tx_slave_bit write_only
pin rx_slave_pin porta rx_slave_bit read_only
pin heart porta 4 write_only

constant space 0xff

constant buffer_size 5

string_constants {
    bit_string = 0s'Bit'
    blink_string = 0s'Blink'
    clock_string = 0s'Clk'
    common_string = 0s'Common'
    done_string = 0s'Done'
    fail_string = 0s'Fail'
    hello_string = 0s'LED4_Test'
    ramps = 0, 1, 0x10, 0x80, 0xff
    read_string = 0s'Read'
    register_string = 0s'Reg'
}

procedure main {
    arguments_none
    returns_nothing

    # Read a byte.

    variable buffer[buffer_size] byte
    variable char byte
    variable count byte
    variable index byte
    variable number byte

    # Print out a welcome message:
    call master_crlf()
    call master_string(hello_string)
    call master_crlf()

    # Main loop
    number := 0
    loop_forever {
	# Get a character:
	tx_slave_pin := 1
	char := master_get()

	# Delay 2/3's of bit make sure that get_byte is done.
	call delay()
	call delay()

	if (0c'0' <= char && char < (0c'9' + 1)) {
	    # Do a multiply by 8 then add in digit:
	    call master_send(char)	    
	    number := (number << 3) + char - 0c'0'
	} else_if (char = 0c's') {
	    # Send byte to brick, no wait:

	    # Echo command and send CRLF:
	    call master_send(char)
	    call master_crlf()

	    # Ship the byte down to the brick:
	    call slave_send(number)
	    number := 0

	} else_if (char = 0c'w') {
	    # Send byte to brick, wait for results:

	    # Echo command and send CRLF:
	    call master_send(char)
	    call master_crlf()

	    # Ship the byte down to the brick ...
	    call slave_send(number)

	    number := 0
	    #call delay()

	    # ...and wait for a response:
	    index := 0
	    while (index < buffer_size) {
		buffer[index] := slave_get()
		index := index + 1
	    }

	    index := 0
	    while (index < buffer_size) {
		call master_octal(buffer[index])
		index := index + 1
	    }

	    # Terminate the output list
	    call master_crlf()
	} else_if (char = 0c'i') {
	    # Interrogate the slave RoboBrick:

	    call master_send(char)
	    call master_crlf()

	    # Initialize the id index:
	    call slave_send(0xfd)

	    # Get the first 8 bytes:
	    call common_test_id_bytes8()

	    # Get the next 8 bytes of random numbers:
	    call common_test_id_bytes8()

	    # Get the next 8 bytes of random numbers:
	    call common_test_id_bytes8()

	    # Get the slave brick name:
	    call common_test_id_string()

	    # Get the vendor name:
	    call common_test_id_string()
	} else_if (char = 0c't') {
	    # Do testing:
	    call master_send(char)
	    call master_crlf()
	    call test()
	} else_if (char = 0c'c') {
	    call master_send(char)
	    call master_crlf()

	    call clock_adjust()
	} else_if (char != 0xfc) {
	    # Just echo back the current number:

	    call master_send(0c'<')
	    call master_octal(char)
	    call master_send(0c'>')

	    # Send a carriage-return line-feed:
	    call master_crlf()
	
	    # Output the character in octal:
	    call master_octal(number)
	
	    # Send a carriage-return line-feed:
	    call master_crlf()

	    # Reset number
	    number := 0
	}
    }
}

procedure clock_adjust {
    arguments_none
    returns_nothing

    # This procedure will adjust the clock to the slave.

    variable command byte
    variable count byte
    variable error byte
    variable error_minimum byte
    variable high byte
    variable low byte

    call master_string(clock_string)
    call master_crlf()
    count := 4
    error := 0xff
    error_minimum := 0xf0
    loop_forever {
	# Print out the clock value:
	call master_send(0c'C')
	call slave_send(0xfa)
	call master_octal(slave_get())

	# Ask for a timing byte:
	call slave_send(0xfb)

	low := 0
 	high := 0
	while (rx_slave_pin) {
	    # Do nothing:
	}
	while (!rx_slave_pin) {
	    low := low + 1
	    if (z) {
		high := high + 1
	    } 
	}

	# Print out high and low:
	call master_send(0c'H')
	call master_octal(high)
	call master_send(0c'L')
	call master_octal(low)

	# If high is less than 2, things are probably pretty broken.
	# We'll try a little fix here, but we are probably pretty
	# screwed up.
	if (high < 2) {
	    low := 0
	}

	# Now think about adjusting clock.
	if (low > clock_target) {
	    #call master_send(0c'+')
	    # Slave clock is too slow (i.e. pulse too long.)
	    error := low - clock_target
	    # Increment clock:
	    command := 0xf9
	    #call slave_send(0xf9)
	} else_if (low < clock_target) {
	    #call master_send(0c'-')
	    # Slave clock is too fast (i.e. pulse too short.)
	    error := clock_target - low
	    # Decrement clock:
	    command := 0xf8
	    #call slave_send(0xf8)
	} else {
	    #call master_send(0c'x')
	    command := 0
	    error := 0
	    error_minimum := 0
	}

	# Print out the error and error minimum:
	call master_send(0c'E')
	call master_octal(error)
	call master_send(0c'M')
	call master_octal(error_minimum)

	if (error = error_minimum) {
	    call master_crlf()
	    return
	} else_if (error < error_minimum) {
	    error_minimum := error
	    error := error + 1
	} else {
	    count := count - 1
	    if (z) {
		error_minimum := error_minimum + 1
		count := 4
	    }
	}

	# Now adjust the clock:
	call slave_send(command)

	call master_crlf()
    }
}

procedure test {
    arguments_none
    returns_nothing

    # This procedure will test the LED10 RoboBrick:

    variable bit byte
    variable leds byte 
    variable temp byte
    variable pattern byte

    # Adjust the clock:
    call clock_adjust()

    # Verify that the common commands are working:
    call common_test()

    # Clear the LEDS:
    call slave_send(0)
    call test_prompt(0)

    # Let's do some simple testing first:
    leds := 1
    while (!(leds@4)) {
	# Set the bits:
	call slave_send(leds)
	call test_prompt(leds)
	call test_verify(leds)
	leds := leds << 1
    }

    # Clear the leds:
    call slave_send(0)

    # Let's test out the bit twiddle commands:
    call master_string(bit_string)
    call master_crlf()
    bit := 0
    leds := 1
    while (bit < 4) {
	# Bit set:
	call slave_send(0x14 | bit)
	call test_verify(leds)

	# Read the bit:
	call slave_send(0x1c | bit)
	temp := slave_get()
	if (temp != 1) {
	    call master_octal(bit)
	    call master_octal(temp)
	    call master_fail(bit_string, 0x30)
	}
	
	# Bit clear:
	call slave_send(0x10 | bit)
	call test_verify(0)

	# Read the bit again:
	call slave_send(0x1c | bit)
	temp := slave_get()
	if (temp != 0) {
	    call master_octal(bit)
	    call master_octal(temp)
	    call master_fail(bit_string, 0x31)
	}

	# Bit toggle:
	call slave_send(0x18 | bit)
	call test_verify(leds)

	# Bit toggle again:
	call slave_send(0x18 | bit)
	call test_verify(0)

	leds := leds << 1
	bit := bit + 1
    }

    # Now do some blink rate tests:
    call master_string(blink_string)
    call master_crlf()
    # First turn the bits on:
    call slave_send(0xf)
    bit := 0
    while (bit < 4) {
	# Set the blink rate:
	call slave_send(0x30 | (bit << 2) | bit)

	# Read the blink rate back:
	call slave_send(0x1c | bit)
	temp := slave_get()
	pattern := (bit << 1) | 9
	if (temp != pattern) {
	    call master_octal(temp)
	    call master_octal(pattern)
	    call master_fail(blink_string, 0x32)
	}
	bit := bit + 1
    }
    # Now turn the bits on and let them blink:
    call test_prompt(0xf)

    # Now clear the blink rates:
    bit := 0
    while (bit < 4) {
	# Clear the blink rate:
	call slave_send(0x20 | bit)
	bit := bit + 1
    }
    call slave_send(0)

    # Now test increment:
    leds := 0
    while (leds < 0x10) {
	call test_verify(leds)

	# Now increment the LED's:
	call slave_send(0x44)
	leds := leds + 1
    }

    # Now test decrement:
    leds := 0x10
    while (leds != 0) {
	leds := leds - 1

	# Now decrement the LED's:
	call slave_send(0x48)

	# Now verify:
	call test_verify(leds)
    }

    # Let's clear the LED's:
    call slave_send(0)

    # Announce that we are done:
    call master_string(done_string)
    call master_crlf()
}

procedure test_verify {
    argument leds byte
    returns_nothing

    # This procedure will verify that the registers contain high and low.

    variable temp byte

    # Read leds register:
    call slave_send(0x40)
    temp := slave_get()
    if (temp != leds) {
	call master_octal(temp)
	call master_octal(leds)
	call master_fail(read_string, 0x50)
    }
}

procedure test_prompt {
    argument leds byte
    returns_nothing

    # This procedure will prompt the user to input a paticular pattern:

    variable count byte
    variable char byte

    # Print high order pattern:
    count_down count 4 {
	char := 0c'.'
	if (leds@3) {
	    char := 0c'*'
	}
	call master_send(char)
	leds := leds << 1
    }
    
    call master_send(0c':')
    while (master_get() = 0xfc) {
	# Do nothing:
    }
    call master_crlf()
}

# The procedures below are used to test the common shared commands:

procedure common_test {
    arguments_none
    returns_nothing

    # This procedure will verify that the common shared commands work.

    variable actual byte

    # Print the ID information:
    # ID reset:
    call slave_send(0xfd)
    # Read the fixed bytes:
    call common_test_id_match(1, 0xc0)
    call common_test_id_match(0, 0xc1)
    call common_test_id_match(8, 0xc2)
    call common_test_id_match(0, 0xc3)
    call common_test_id_match(0, 0xc4)
    call common_test_id_match(0, 0xc5)
    call common_test_id_match(0, 0xc6)
    call common_test_id_match(0, 0xc7)
    call master_crlf()
    call common_test_id_bytes8()
    call common_test_id_bytes8()
    # Read the brick name:
    call common_test_id_string()
    # Read the vendor name:
    call common_test_id_string()
    # Verfify that we don't read off the end of the id and crash:
    call common_test_id_next()
    # Reset id:
    call slave_send(0xfd)
    # Verify that we are still alive:
    call common_test_id_match(1, 0xc8)

    # Read glitch:
    # Clear glitch register:
    call slave_send(0xfe)
    actual := slave_get()
    # Send a couple of glitches:
    call slave_send(0xff)
    call slave_send(0xff)
    # Read the glitch register:
    call slave_send(0xfe)
    if (slave_get() != 2) {
	call master_fail(common_string, 0xc9)
    }

    # Do a clock pulse:
    call slave_send(0xfb)
    if (slave_get() != 0) {
	call master_fail(common_string, 0xca)
    }
    # Read clock:
    call slave_send(0xfa)
    actual := slave_get()
    # Increment:
    call slave_send(0xf9)
    # Decrement:
    call slave_send(0xf8)
    # Read clock again:
    call slave_send(0xfa)
    if (actual != slave_get()) {
	call master_fail(common_string, 0xcb)
    }
}

procedure common_test_id_match {
    argument desired byte
    argument test_number byte
    returns_nothing

    # This procedure will verify that the next byte in the id is {desired}.

    if (desired != common_test_id_next()) {
	call master_fail(common_string, test_number)
    }
}

procedure common_test_id_bytes8 {
    arguments_none
    returns_nothing

    # This procedure will print out the next 8 bytes of the id in octal.

    variable count byte

    count_down count 8 {
	call master_octal(common_test_id_next())
    }
    call master_crlf()
}

procedure common_test_id_string {
    arguments_none
    returns_nothing

    # This procedure will print out the next id string.

    variable count byte

    count_down count (common_test_id_next()) {
	call master_send(common_test_id_next())
    }
    call master_crlf()
}

procedure common_test_id_next {
    arguments_none
    returns byte

    # This procedure returns the next byte from the identification string.

    call slave_send(0xfc)
    return slave_get()
}

# The following procedures are used to communicate with the master:

procedure master_crlf {
    arguments_none
    returns_nothing

    # This procedure will output a carriage-return line-feed
    # to the master.

    call master_send(cr)
    call master_send(lf)
}

procedure master_fail {
    argument test_name string
    argument test_number byte
    returns_nothing

    # This procedure will output `fail' followed by a carriage return
    # and line feed.

    call master_string(fail_string)
    call master_string(test_name)
    call master_octal(test_number)
    call master_crlf()
}

procedure master_get {
    arguments_none
    returns byte

    # This procedure will get the next byte or return 0xfc if
    # no byte is forthcoming.

    return get_byte(rx_master_mask)
}

procedure master_octal {
    argument number byte
    returns_nothing

    # This procedure will output {number} in octal to the tx port.

    # Output the character in octal:
    call master_send((number>>6) + 0c'0')
    call master_send(((number>>3) & 7) + 0c'0')
    call master_send((number & 7) + 0c'0')
    call master_send(sp)
}

procedure slave_get {
    arguments_none
    returns byte

    # This procedure will get a byte from the slave or return 0xfc
    # if no byte is forthcoming.

    return get_byte(rx_slave_mask)
}

procedure slave_send {
    argument data byte
    returns_nothing

    # This procedure will send one byte of {data} to the slave.

    call send_byte(data, tx_slave_mask)
}

# The last procedures do character sending and receiving:

procedure get_byte {
    argument mask byte
    returns byte

    # Get an 8-bit byte from {mask} bit of {porta} and return it.
    # If no character shows up in a while 0xfc is returned.

    variable count byte
    variable char byte

    # Wait until a start bit arrives:
    count := 0
    while (porta & mask != 0) {
	count := count - 1
	if (count = 0) {
	    return 0xfc
	}
	call delay()
    }

    # Skip over the start bit:
    call delay()
    call delay()
    call delay()

    # Sample in the middle third of each data bit:
    char := 0
    count_down count 8 {
	call delay()
	char := char >> 1
	if (porta & mask != 0) {
	    char := char | 0x80
	}
	call delay()
	call delay()
    }

    # Skip over 1/3 of the stop bit:
    call delay()

    return char
}

procedure send_byte {
    argument char byte
    argument mask byte
    returns_nothing

    # Send {char} to {mask} bit of {porta}.

    variable count byte
    variable mark byte


    # Send the start bit:
    mark := mask ^ space
    porta := mark
    call delay()
    call delay()
    call delay()

    # Send the data:
    count_down count 8 {
	if (char@0) {
	    porta := space
	} else {
	    porta := mark
	}
	char := char >> 1
	call delay()
	call delay()
	call delay()
    }

    # Send the stop bit:
    porta := space
    call delay()
    call delay()
    call delay()
}

procedure master_send {
    argument character byte
    returns_nothing

    # This procedure will output {character} to the master.

    call send_byte(character, tx_master_mask)
}

procedure master_string {
    argument message string
    returns_nothing

    # This procedure will output {message} to the master.

    variable size byte
    variable index byte

    index := 0
    while (index < message.size) {
	call master_send(message[index])
	index := index + 1
    }
    call master_send(sp)
}

procedure delay {
    arguments_none
    returns_nothing
    uniform_delay instructions_per_delay

    # Delay 1 third of a bit:
}