# #############################################################################
#
# 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 pic16f628 cp=off cpd=off lvp=off bowden=off mclre=on pwrte=off wdte=off fosc=xt
constant clock_rate 10000000
constant clock_ticks_per_instruction 4
constant instructions_per_second clock_rate / clock_ticks_per_instruction
constant baud_rate 2400
constant instructions_per_bit clock_rate / (clock_ticks_per_instruction * baud_rate)
constant delays_per_bit 3
constant instructions_per_delay instructions_per_bit / delays_per_bit
constant extra_instructions_per_bit 12

constant extra_instructions_per_delay extra_instructions_per_bit / delays_per_bit
constant delay_instructions instructions_per_delay - extra_instructions_per_delay

# The null pulse that comes back from a clock pulse command is supposed to be
# exactly 9 bits long.  9 bits at 2400 baud is 9/2400 = 3.75mS.  The number
# iterations through the loop is 3.75mS / (number of instructions per iteration.)
constant nine_bits_instructions (clock_rate * 9) / (clock_ticks_per_instruction * baud_rate)
constant instructions_per_iteration 7
constant iterations_for_nine_bits nine_bits_instructions / instructions_per_iteration
constant iterations_high iterations_for_nine_bits / 256
constant iterations_low iterations_for_nine_bits - (iterations_high * 256)

# Some character constants:
constant sp 32
constant cr 13
constant lf 10

# Some bit definitions:
constant rx_slave_bit 5
constant tx_slave_bit 4
constant rx_master_bit 1
constant tx_master_bit 2
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

# Some register definitions:
register status 3
bind c status@0
bind z status@2

# Some port and pin definitions:
#port porta a unused none
port portb b bits_only read_write_static
pin tx_master_pin portb tx_master_bit write_only
pin rx_master_pin portb rx_master_bit read_only
pin tx_slave_pin portb tx_slave_bit write_only
pin rx_slave_pin portb rx_slave_bit read_only

# Miscellaneous constants:
constant space 0xff
constant buffer_size 3

string_constants {
    bit_string = 0s'Bit'
    clock_string = 0s'Clk'
    common_string = 0s'Common'
    done_string = 0s'Done'
    fail_string = 0s'Fail'
    hello_string = 0s'Shaft2_Test'
    interrupt_string = 0s'Interrupt'
    patterns = 0, 1, 2, 4, 8, 0x10, 0x20, 0x40, 0x80, 0xff, 0
    register_string = 0s'Reg'
    shaft_string = 0s'Shaft'
    test_string = 0s'Test'
}

global temp byte

procedure main {
    arguments_none
    returns_nothing

    # Read a byte.

    variable buffer[buffer_size] byte
    variable char 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(number)
	    number := 0
	} 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 {
    argument adjust byte
    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
    variable target byte

    target := iterations_low - adjust
    count := 2
    error := 0xff
    error_minimum := 0xf0

    # Print out the target:
    call master_send(0c'T')
    call master_octal(iterations_high)
    call master_octal(target)
    call master_crlf()

    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)

	# Now think about adjusting clock.
	if (high > iterations_high) {
	    # Clock pulse is too long; slave clock is too slow:
	    command := 0xf9
	    error := 0xff - target
        } else_if (high < iterations_high) {
	    # Clock pulse is too short; slave clock is too fast:
	    command := 0xf8
	    error := target
	} else {
	    # The high 8-bits are equal:
	    if (low > target) {
		# Clock pulse is too long; slave clock is too slow:
		command := 0xf9
		error := low - target
	    } else_if (low < target) {
		# Clock pulse is too short; slave clock is too fast:
		command := 0xf8
		error := target - low
	    } else {
		# Exact match; we are done:
		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 := 2
	    }
	}

	# Now adjust the clock:
	call slave_send(command)

	call master_crlf()
    }
}

procedure test {
    arguments_none
    returns_nothing

    # This procedure will test the Shaft2 RoboBrick:

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

    # Verify that we can interrupt:
    #call test_interrupt_setup(0)
    #call test_interrupt_setup(1)
    #call interrupt_test()

    # Test some shaft inputs:
    call master_string(shaft_string)
    call master_string(test_string)
    call master_crlf()
    call test_shaft(0, 0x10, 0)
    call test_shaft(0, 0x10, 1)

    # Now test interrupt ranges:
    call master_string(interrupt_string)
    call master_string(test_string)
    call master_crlf()
    call test_interrupt(0)
    call test_interrupt(1)

    # Let's go test some registers:
    call master_string(register_string)
    call master_string(test_string)
    call master_crlf()
    # Shaft low:
    call test_byte_register(6, 2, 0x30)
    call test_byte_register(7, 3, 0x31)
    # Shaft:
    call test_word_register(4, 0, 0x34)
    call test_word_register(5, 1, 0x36)
    # High threshold:
    call test_word_register(0x10, 0x14, 0x38)
    call test_word_register(0x11, 0x15, 0x39)
    # Low threshold:
    call test_word_register(0x12, 0x16, 0x3a)
    call test_word_register(0x13, 0x17, 0x3b)

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

procedure test_interrupt_setup {
    argument shaft byte
    returns_nothing

    # This procedure will set up the registers for shaft to be interrupt safe.

    # Set low threshold:
    call slave_send(0x12 | shaft)
    call slave_send(0)
    call slave_send(0x10)

    # Set high threshold:
    call slave_send(0x10 | shaft)
    call slave_send(0)
    call slave_send(0x30)

    # Set the shaft to the middle:
    call slave_send(4 | shaft)
    call slave_send(0)
    call slave_send(0x20)
}

procedure test_interrupt {
    argument shaft byte
    returns_nothing

    # This procedure will test interrupts shaft.

    call test_interrupt_setup(0)
    call test_interrupt_setup(1)

    # Now enable interrupts:
    call slave_send(0xf2)

    # Let people know what is going on:
    call master_octal(shaft)
    call master_send(0c':')
    call master_octal(0x10)
    call master_send(0c'?')
    call master_octal(0x30)

    # Now wait for interrupt:
    while (rx_slave_pin) {
	call delay()
    }
    call master_crlf()
}

procedure test_shaft {
    argument high byte
    argument low byte
    argument shaft byte
    returns_nothing

    # This procedure will verify that the shaft can be
    # positioned to {high} and {low}.

    variable current_high byte
    variable current_low byte

    # Let the user know what we are shooting for:
    call master_octal(high)
    call master_octal(low)
    call master_send(0c':')
    call master_crlf()

    current_high := high + 1
    current_low := low + 1

    while (high != current_high || low != current_low) {
	call slave_send(shaft)
	current_high := slave_get()
	current_low := slave_get()
	call master_octal(current_high)
	call master_octal(current_low)
	call master_send(cr)
    }
    call master_crlf()
}

procedure test_byte_register {
    argument set_command byte
    argument read_command byte
    argument error byte
    returns_nothing

    # This procedure will test the ability to set and read back
    # a byte register:

    variable index byte
    variable pattern byte

    index := 0
    while (index < patterns.size) {
	pattern := patterns[index]
	call slave_send(set_command)
	call slave_send(pattern)

	call slave_send(read_command)
	temp := slave_get()
	if (temp != pattern) {
	    call master_octal(pattern)
	    call master_octal(temp)
	    call master_fail(register_string, error)
	}
	index := index + 1
    }
}

procedure test_word_register {
    argument set_command byte
    argument read_command byte
    argument error byte
    returns_nothing

    # This procedure will test the ability to set and read
    # back a word register:

    variable low byte
    variable low_index byte
    variable high byte
    variable high_index byte

    high_index := 0
    while (high_index < patterns.size) {
	high := patterns[high_index]
	low_index := 0
	while (low_index < patterns.size) {
	    low := patterns[low_index]
	    # Set the register:
	    call slave_send(set_command)
	    call slave_send(high)
	    call slave_send(low)

	    # Verify its contents:
	    call slave_send(read_command)
	    temp := slave_get()
	    if (temp != high) {
		call master_octal(high)
		call master_octal(temp)
		call master_fail(register_string, error)
	    }
	    temp := slave_get()
	    if (temp != low) {
		call master_octal(low)
		call master_octal(temp)
		call master_fail(register_string, error | 1)
	    }
	    low_index := low_index + 1
	}
	high_index := high_index + 1
    }
}

# 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(16, 0xc2)
    call common_test_id_match(1, 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}.

    variable id byte

    id := common_test_id_next()
    call master_octal(id)
    if (desired != id) {
	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 procedures below are used to test the shared interrupt commands:

procedure interrupt_test {
    arguments_none
    returns_nothing

    # This procedure tests the common shared interrupt commands.

    variable counter byte

    # Clear interrupt bits:
    call slave_send(0xf0)
    call interrupt_read(0, 0xd0)

    # Set/clear interrupt pending bit only:
    call slave_send(0xf5)
    call interrupt_read(1, 0xd1)
    call slave_send(0xf4)
    call interrupt_read(0, 0xd2)
    call slave_send(0xf1)
    call interrupt_read(1, 0xd3)
    call slave_send(0xf0)
    call interrupt_read(0, 0xd4)

    # Set/clear interrupt enable bit only:
    call slave_send(0xf7)
    call interrupt_read(2, 0xd5)
    call slave_send(0xf6)
    call interrupt_read(0, 0xd6)
    call slave_send(0xf2)
    call interrupt_read(2, 0xd7)
    call slave_send(0xf0)
    call interrupt_read(0, 0xd8)

    # Now set both the interrupt enable and pending bit.
    # This must trigger an interrupt.

    call slave_send(0xf3)
    count_down counter 3 {
	call delay()
    }
    if (rx_slave_pin) {
	# No interrupt detected:
	call master_fail(interrupt_string, 0xd9)
    }
    # Read the interrupt enable bit is cleared as a side effect
    # of reading the bit.
    call interrupt_read(1, 0xda)

    # Clear the interrupt pending bit:
    call slave_send(0xf0)
    call interrupt_read(0, 0xdb)
}

procedure interrupt_read {
    argument desired byte
    argument test_number byte
    returns_nothing

    # This procedure will verify that the interrupt bits match {desired}.

    call slave_send(0xef)
    temp := slave_get()
    if (temp != desired) {
	call master_octal(temp)
	call master_fail(interrupt_string, test_number)
    }
}

# 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 {portb} 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 (portb & 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:
    # 1 cycle:
    char := 0
    # 2 cycles for loop setup:
    # 1+2 = 3
    nop extra_instructions_per_bit - 3
    count_down count 8 {
	call delay()
	# 2 cycles:
	char := char >> 1
	# 3 cycles:
	if (portb & mask != 0) {
	    char@7 := 1
	}
	call delay()
	call delay()
	# 3 cycles at end of loop:
	# 2+3+3 = 8
	nop extra_instructions_per_bit - 8
    }

    # 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 {portb}.

    variable count byte
    variable mark byte

    # Send the start bit:
    # 3 cycles:
    mark := mask ^ space
    # 1 cycle (mark is already in W):
    portb := mark
    call delay()
    call delay()
    call delay()
    # 2 cycles for loop setup:
    # 3+1+2 = 6
    nop extra_instructions_per_bit - 6

    # Send the data:
    count_down count 8 {
	# 5 cycles:
	if (char@0) {
	    portb := space
	} else {
	    portb := mark
	}
	# 2 cycles:
	char := char >> 1
	call delay()
	call delay()
	call delay()
	# 3 cycles at end of loop:
	# 5+2+3 = 10
	nop extra_instructions_per_bit - 10
    }

    # Send the stop bit:
    # 1 cycle to finish off previous loop:
    nop 1
    # 2 cycles:
    portb := space
    call delay()
    call delay()
    call delay()
    # 4 cycles for call/return:
    # 4 cycles for tw arguments:
    # 2+4+4 = 10
    nop extra_instructions_per_bit - 10
}

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 delay_instructions

    # Delay 1 third of a bit:
    watch_dog_reset
}