\ Traffic Light, By Michael Jeffery Copyright 2019, licensed under the GPL.
\ For use with Mecrisp-Stellaris by Matthias Koch. https://sourceforge.net/projects/mecrisp/
\ The original shell of this was taken from the Matthias Koch 'Blinky' and reworked.
\ Thanks also to Terry Porter.
\ Traffic Light, uses PB13, PB14, PB15 on a Blue Pill Module running Forth - Mecrisp Stellaris.
\ This will run a Traffic Light sequence, around 12 sec for each of the Green and Red LEDs.
\ You can change the Timing sequence in the Loop, 25000000 0 or 4200000 0 for a different result.
\ In Terminal you should see the word 'STOP' then 'AMBER' then 'GO' printed with four or so spaces
\ after each word on every new step.
\ As the delay loops are Long, 'key? until' only works at the end of each cycle, so you may have 
\ to wait a little for press 'any key' to end the program. An interrupt would work better here.
\ Copy and paste this text into your Terminal, hit enter, then type Traffic when it's done.
\ If you get errors, set the EOL (End Of Line) delay to 200ms in your Terminal.
\ Type Traffic to Start the sequence.


$40010C00 constant GPIOB

GPIOB $00 + constant GPIOB_CRL \ Reset value: $44444444 PB0-PB7 are configured in CRL, PB8-PB15 in CRH.
GPIOB $04 + constant GPIOB_CRH \ Reset value: $44444444 1: Push-Pull output, 4: Floating input.
GPIOB $08 + constant GPIOB_IDR
GPIOB $0C + constant GPIOB_ODR         \ Configuration Settings for GPIO Port B
GPIOB $10 + constant GPIOB_BSRR        \ on the Blue Pill Module.
GPIOB $14 + constant GPIOB_BRR
GPIOB $18 + constant GPIOB_LCKR

: Traffic ( -- )          \ Start of Traffic 'Word'.
$11144444 GPIOB_CRH !     \ PB15: PB14: PB13: sets Push-Pull Output.
begin                     \ Start Begin - Until loop.
1 13 lshift GPIOB_ODR !   \ GREEN, GO ON, Set Pin13 ON. 
." GO    "                \ Prints GO on the Terminal.
25000000 0 do loop        \ Delay Loop, XXX to 0.
1 14 lshift GPIOB_ODR !   \ AMBER, Wait ON, Set Pin14 ON.
." AMBER    "             \ Prints AMBER on the Terminal.
4200000 0 do loop         \ Delay Loop, XXX to 0.
1 15 lshift GPIOB_ODR !   \ RED, STOP ON, Set Pin15 ON.
." STOP    "              \ Prints STOP on the Terminal.
25000000 0 do loop        \ Delay Loop, XXX to 0.
1 14 lshift GPIOB_ODR !   \ AMBER, Wait ON, Set Pin14 ON.  
." AMBER    "             \ Prints AMBER on the Terminal.     
4200000 0 do loop         \ Delay Loop, XXX to 0.   
key? until                \ Ends if any Key pressed, or Loops forever.
;                         \ End of traffic 'Word'.



\ So here we created a single new Word called Traffic, that's basically how Forth works.
\ Every time you type this Word the Code will now run (as long as you save it, see below).
\ You will need to include the Header first to configure GPIOB as well, if not previously saved.
 
 
\ If you are in the UK you may want to leave everything 'as is'.
\ If you are in the USA you may want to remove the last AMBER set, so Green goes directly to
\ Red. There is no Red and Amber at once before Green though, that's the advanced version ~ :o)
\ If you want this Word 'Traffic' to remain after a reset you could include 'compiletoflash'
\ above the Header, without the quotation marks of course and it will then be included 
\ in your dictionary, along with the Header config for GPIOB.

 
\ Wiring, any LED Resistor value from around 120 Ohms to 2K2 Ohms should work, LED Pos+ to the 
\ Blue Pill pin PB13, PB14 and PB15. Blue Pill output 'high' is 3.3V.
\ If in doubt use an online LED / Resistor Calculator, there's hundreds out there.
\ Other than that you probably won't get any further support on this part of the project.
\
\ Good Luck!




\ Swap Red for Green order, starts on RED vs Green, easy just swap each LED part.
\ Use the same Header as above also.
 
\ : Traffic ( -- ) 
\ $11144444 GPIOB_CRH !     \ PB15: PB14: PB13: Push-Pull Output.
\ begin                     \ Start Begin - Until loop.
\ 1 15 lshift GPIOB_ODR !   \ RED, STOP ON, Set Pin15 ON.
\ ." STOP    "              \ Prints STOP on the Terminal.
\ 25000000 0 do loop        \ Delay Loop, XXX to 0.
\ 1 14 lshift GPIOB_ODR !   \ AMBER, Wait ON, Set Pin14 ON. 
\ ." AMBER    "             \ Prints AMBER on the Terminal.
\ 4200000 0 do loop         \ Delay Loop, XXX to 0.
\ 1 13 lshift GPIOB_ODR !   \ GREEN, GO ON, Set Pin13 ON. 
\ ." GO    "                \ Prints GO on the Terminal.
\ 25000000 0 do loop        \ Delay Loop, XXX to 0.
\ 1 14 lshift GPIOB_ODR !   \ AMBER, Wait ON, Set Pin14 ON.  
\ ." AMBER    "             \ Prints AMBER on the Terminal.                
\ 4200000 0 do loop         \ Delay Loop, XXX to 0.   
\ key? until                \ Ends if any Key pressed, or Loops forever.
\ ;
\
\ Remove the First AMBER Set in this instance to sequence RED-to-GREEN, without AMBER.
\ TEST IT !
\
\ You can actually make the Red-Amber both briefly ON, before Green, it involves addressing
\ the GPIOB_ODR directly and with two bits set and you also adjust a couple of delay tmings.
\ If there's enough interest you may see a Part II.
\
\ And you can have this Traffic word run from Boot-Up, Power ON, without a PC but it requires 
\ a little more information so you don't get into trouble first. The advanced lesson again.
\ You could try the Common Problems page here, (Search Index) pay attention to the warning 
\ or you may end up having to re-flash your Blue Pill with Mecrisp Stellaris all over again.
\ For now this should get you started using FORTH on this Traffic Light project.
\
\ Enjoy.