5473

Mini PLC ideal for model trains and small hobby (automation) projects. Update now with 4 analog inputs

STM32F407VGT6 Discovery board

Easy to program

Ideal for model building or other hobby applications

Cheap

16 digital inputs
16 digital outputs

can be expanded to:
64 digital inputs
64 digital outputs

4 analog inputs
 possible comparisons
  AI = equal to
  AI > greater than
  AI < less than
  AI >< greater than and less than

4 PWM outputs (hardware PWMs do not take up processor time)
  frequency can be set per PWM

PWM outputs can be controlled by an analog input, for example to control a speed control by a potentiometer.
 Use the PWM_F command for this.

64 internal markers

64 internal counters
  counter_up input
  counter_down input
  counter_reset input

  counter_up output                     1 if count value reached
  counter_down output                1 if count value 0

64 internal timers
  timer input
  timer_reset input
  timer_output                                1 if set time reached
  adjustable between 0.1 second and 99:59:59:90

TMR56 to TMR63 continuous timers
  deliver square wave of set time if input 1

Due to the limited dimensions of the screen, programming can only be done using Arduino logic

&&     AND
||        OR
^        XOR
!         NOT
( 
)
/\       RISING EDGE
\/       FALLING EDGE
= 
SET
RST

Cycle time adjustable between 10 milliseconds and 100 milliseconds (hardware timer interrupt)

To keep the Timer seconds the same as real seconds set to:
 10 milliseconden
 20 milliseconden
 25 milliseconden
 50 milliseconden
 100 milliseconden

Program can be saved in the FLASH memory of the STM32F407.

16000 bytes of freely programmable memory

Maximum 1000 lines.

The number of lines and the cycle time are determined by the number of bytes per line.

Each program line can be a maximum of 20 bytes long (screen size and RAM storage capacity limitation)

with maximum usage of bytes in each line, the maximum number of lines is 800.

bytes per instruction :

1 byte
&& || ^ ! = SET RST ( ) /\ \/

2 bytes
INxx OUTxx Mxx TMRxx CTRUxx CTRDxx TMR_Rxx CTR_Rxx

3 bytes
AI = x %%% AI nummer instel percentage
AI > x %%% AI nummer instel percentage
AI < x %%% AI nummer instel percentage
PWM x %% % PWM nummer procent uitsturing
PWM_F x x PWM_F nummer nummer van analoge ingang die PWMx stuurt

4 bytes
AI >< x %%% %%% AI nummer instel percentage > instel percentage <

Required cycle time depends on the number of selected inputs/outputs and program length

time required for 16 inputs/outputs without program
331 microseconden

time required for 64 inputs/outputs without program
659 microseconden

average time per instruction
1.5 microseconden

For full use of the program space with 64 inputs/outputs, 50 milliseconds should be more than sufficient.

659 microseconden + (16000 instructies * 1.5 microseconden) = 24659 microseconden.

Analog and digital inputs are read at the beginning of the program

Digital outputs and PWMs are calculated during the runtime of the program but only written to the outputs at the end of the program.

Program line processing without brackets is done from left to right.

Program line processing with brackets, first all logic within the brackets from left to right until all brackets are processed and then the entire line from left to right.

Automatic restart of the program if saved in FLASH and prog/run switch set to run.

a program example

0000     IN 0 = OUT 0 
0001     IN 0 = TMR 56 
0002     TMR 56 = OUT 1 
0003      IN 0 && ! TMR 56 = OUT 2 
0004     TMR 56 = CTRU 0 
0005     CTRU 0 && TMR 56 = CTRU 1 
0006     CTRU 0 = OUT 3 
0007     CTRU 1 = OUT 4 
0008     /\ CTRU 1 = CTR_R 0 
0009     /\ CTRU 0 = CTR_R 1 
0010     AI >< 0 10 50 = OUT 5 
0011     IN 0 = PWM_F 0 0 
0012     AI > 0 25 = PWM 1 25 
0013     ! OUT 6 = OUT 6