1. 328eForth Workshop
C. H. Ting
February 16, 2012
SVFIG

2. Summary Optimized FORTH for Arduino Uno ATmega328P Demonstrations
BLINK a LED
TONE Generator
SERVO Motors
TRAFFIC Controller

3. Optimized Forth for Arduino
Subroutine Thread Model
Fully optimized
Uniform byte addressing
Case insensitive
Interpreter is in Bootloader section
Optimized flash programming
Visible words are reduced to 140 for ease of learning

4. ATmega328P 8 Bit microcontroller, 131 instructions 20 MIPS at 20 MHz
32KB Flash, 2 KB RAM, 1 KB EEPROM
3 Counter/Timers
6 Channels 10-bit ADC
USART, SPI, I2C, ISP
23 Programmable I/O lines V

5. BLINK a LED Toggle LED HEX 20 24 C! \ make Line 13 an output pin
C! \ toggle Line 13 LED
BLINK program
: MS ( n -- ) FOR AFT $1CB FOR NEXT THEN NEXT ;
: BLINK C! BEGIN C! 400 MS AGAIN ;
FLUSH
BLINK

6. TONE Generator Timer/Counter1 Setup HEX 2 24 C! \ set Line 9 as output
40 80 C! \ set CTC mode
!\ init compare reg
9 81 C! \ prescaler=1, start

7. TONE Generator : /SO A000 88 ! ; : DO 77B1 88 ! ; : RE 6AAA 88 ! ;
: ME 5F07 88 ! ;
: FA 59DB 88 ! ;
: SO ! ;
: LA ! ;
: MS ( n -- ) FOR AFT $1CB FOR NEXT THEN NEXT ;
: 1/4 100 MS ;
: 1/2 200 MS ;
: 1/8 400 MS ;

8. TONE Generator : PHRASE1 DO 1/4 RE 1/4 ME 1/4 DO 1/4 ;
: PHRASE2 ME 1/4 FA 1/4 ME 1/4 SO 1/2 ;
: PHRASE3 SO 1/8 LA 1/8 SO 1/8 FA 1/8 ME 1/4 ME 1/4 DO 1/4 ;
: PHRASE1 DO 1/4 /SO ¼ ME 1/4 DO 1/2 ;
: SONG
2 24 C! C! C!
PHRASE1 PHRASE1
PHRASE2 PHRASE2
PHRASE3 PHRASE3
PHRASE4 PHRASE4
0 81 C! ;

9. SERVO Motors Assembling by AVR Assembler 2
Simulating by AVR Simulator 2
In System Programming with AVRISP mkll
Running 328eForth from HyperTerminal

10. SERVO Motors HEX : INIT-PORTS E 24 C! 68 2A C! \ OUTPUT PORTS
A3 44 C! C! \ TCCR0A, TCCR0B
18 47 C! C! \ OCR0A, OCR0B
A1 80 C! D 81 C! \ TCCR1A, TCCR1B
18 88 C! 18 8A C! \ OCR1A, OCR1B
A3 B0 C! 7 B1 C! \ TCCR2A, TCCR2B
18 B3 C! 18 B4 C! \ OCR2A, OCR2B ;

11. SERVO Motors : S1 ( N -- ) 88 C! ; : S2 ( N -- ) 8A C! ;
: S3 ( N -- ) B3 C! ;
: S4 ( N -- ) B4 C! ;
: S5 ( N -- ) 47 C! ;
: S6 ( N -- ) 48 C! ;
FLUSH

12. TRAFFIC Controller : init-ports fc 2a c! 3 24 c! \ output ports
3f 28 c! c 25 c! ; \ input ports, pullup
: seconds
for aft 100 for 400 for next next then next ;
: lights ( n -- )
dup 2b c! \ PD outputs
100 / C or 25 c! ; \ PB outputs, maintain pullups
: switches ( -- n )
* \ PB inputs
26 or \ PC inputs
dup cr . ;

13. TRAFFIC Controller : N-S begin 104 lights 5 seconds switches c3a and
if 108 lights 2 seconds then
switches a and if 130 lights 3 seconds then
switches c30 and until ;
: E-W begin 50 lights 5 seconds
switches 82f and
if 90 lights 2 seconds then
switches 820 and
if 310 lights 3 seconds then
switches f and until ;
: go init-ports begin N-S E-W ?key until drop ;
flush

14. Turn Key Application Application Turn Key Burn Fuses
: go init-ports
begin N-S E-W ?key until drop ;
Turn Key
‘ go 100 !
100 erase
write
Burn Fuses
Lfuse=F2, Hfuse=D8, Efuse=FD

15. Tao of Arduino No external crystal No external reset
No current limiting resistors to drive LED’s
No external pull up resistors to read sensors
2 AA batteries are sufficient for power

16. Conclusion Arduino is the best platform to teach FORTH.
ATmega328 is the simplest microcontroller for embedded applications.
328eForth is the easiest way to build applications on Arduino Uno.

17. 為學日益,為道日損. 損之又損,以至於無. 為無為而無不為.
Ardunio之道
為學日益,為道日損.
損之又損,以至於無.
為無為而無不為.