Random number -> Corresponding LED lit (n00besque content contained)

[AvionicsMaster1]

I've tried to randomize 20 LEDs hooked up as shown in the attachment with the following code:
(Sorry, I've had to retype it. Long story.)

clear
define osc4
ansel=0
comcon0=7
adcon0=0
 
delay var word
myword var word
mybyte var byte
previous_random var byte
gpiostate var byte
tristate var byte
 
delay = 250
 
main:
random myword
mybyte = (myword//20)
if previous_random = mybyte then goto main
gosub high_led
pause delay
gpio = %000000
pause delay
previous_random= mybyte
goto main
 
high led:
lookup mybyte,[%000001, etc for 20 LEDs], gpiostate
gpio = gpiostate
lookup mybyte,[%111100, etc for 20 LEDs], tristate
trisio = tristate
return

The problem I'm having is two fold.

First, LED0 never lights. I've watched it for a about 3 minutes several times and that first LED never lights. Any ideas why?

Secondly, although I implement the previous_random scheme shown previously in the thread, I often get an LED that will light repeatedly before moving on. Any ideas why?

As always, most of your thoughts are appreciated.

[Archangel]

We really need to see the entire code esp. the lookup tables.

[HankMcSpank]

It worked perfectly for me ....any reason you have not copied the code verbatim?

Re LED1 never lighting, what happens if you comment out the random aspect & simple make mybyte = 1 (where 1 is the LED you're not seeing lighting up etc)...this should light the suspect LED up all the time & proves both the wiring/LED at least.

Re the same LED lighting in succession, I'd approach this by getting some debug/hserout info of 'mybyte' onscreen....else you're grasping in the dark. (no pun intended!)

[AvionicsMaster1]

I did run another program to ensure all the LEDs are hooked up and working. They all work using the cut and pasted look up tables provided.

Hank, when you say it worked perfectly did you use the schematic I provided? The last time I chased a problem with these LEDs, it turned out to be the circuit not the code. If you look here http://www.picbasic.co.uk/forum/show...ght=wood+chuck you'll see what I mean.

Here are the look up tables.

lookup mybyte,[%000001, %000010, %000001, %000100, %000001, %010000, %000001, %100000, %000010, %000100, %000010, %010000, %000010, %100000, %000100, %010000, %000100, %100000, %010000, %100000], gpiostate
gpio= gpiostate
lookup mybyte,[%111110, %111100, %111010, %111010, %101110, %101110, %011110, %011110, %111001, %111001, %101101, %101101, %011101, %011101, %101011, %101011, %011011, %011011, %001111, %001111],tristate
trisio= tristate

I don't currently have the knowledge to display my number on screen but if the LED is lit by another program, proving it does work, then looking at a number will only tell me that the LEDs number never comes up.

[boroko]

I wonder if someone could explain the
"MyByte=(MyWord//6)+1" part? // = Remainder (Modulus)? It isn't clear to me what this is doing and how it is extracting the 6 variables.

I need to randomize 8 LEDs and would like to understand it better.

Thanks
Bo

[AvionicsMaster1]

If you do the math with a calculator you'll, in my opinion, never understand modulus. Use paper and pencil for some small numbers and you'll see how modulus works.

I believe to randomize 8 LEDs all you need to do is change the 6 to an 8. Like
Random myword
mybyte=(myword//8)

Depending on how you use mybyte depends on whether or not you need to +1 after myword//8.

I'm sure someone will chime in and say I've messed up but there you have it.