I used 2N2222A's with 1.2K base resistors.Transistors are 2N3904 NPN. Most people see that they're sourcing drivers and assume they're PNP (because the drawing is so fuzzy).
I've got 330's on the rows. Too much, but they were there and I wanted to start out safe.and 20 ohm current limiting resistors on the rows
Nag, nag, nag!I don't see a bypass cap' across VDD and VSS pins in that photo'.
Hi Gayan,Nice design Sir ...I like it very much....
May I hack your hardware design? but not the code
Also can you show the underneath of your board Sir if you don't mind?
A YouTube video of the test code at work.
No it doesn't. I slowed the clock down to a crawl and still get the same LEDs lit, but flickering now, as the update rate is too slow. Some of them are brighter than others and some aren't on at all. Is it supposed to animate (move)? I haven't really deciphered that ISR yet. Anyway, nothing moves.Looks very nice. Did you say my program doesn't work?
No it doesn't. I slowed the clock down to a crawl and still get the same LEDs lit, but flickering now, as the update rate is too slow. Some of them are brighter than others and some aren't on at all. Is it supposed to animate (move)? I haven't really deciphered that ISR yet. Anyway, nothing moves.
Maybe what I'll do is draw up a schematic of what I've done and let you have a look. Maybe I did something different than you. Your schematic seemed just a tiny bit unclear to me. What program is that?
led[0] = led[19] = 31; // 100% brightness
led[1] = led[18] = 23; // 90% brightness
led[2] = led[17] = 18; // 80% brightness
led[3] = led[16] = 14; // 70% brightness
led[4] = led[15] = 11; // 60% brightness
led[5] = led[14] = 9; // 50% brightness
led[6] = led[13] = 7; // 40% brightness
led[7] = led[12] = 5; // 30% brightness
led[8] = led[11] = 3; // 20% brightness
led[9] = led[10] = 2; // 10% brightness
Ah. Yes it is. The brightness setting code I had looked like this:The program is working then. My program doesn't animate the LEDs.
led[0] = led[19] = 1; //
led[1] = led[18] = 1; //
led[2] = led[17] = 4; //
led[3] = led[16] = 0; //
led[4] = led[15] = 0; //
led[5] = led[14] = 1; //
led[6] = led[13] = 1; //
led[7] = led[12] = 0; //
led[8] = led[11] = 1; //
led[9] = led[10] = 1; //
led[0] = led[19] = 31; // 100% brightness
led[1] = led[18] = 23; // 90% brightness
led[2] = led[17] = 18; // 80% brightness
led[3] = led[16] = 14; // 70% brightness
led[4] = led[15] = 11; // 60% brightness
led[5] = led[14] = 9; // 50% brightness
led[6] = led[13] = 7; // 40% brightness
led[7] = led[12] = 5; // 30% brightness
led[8] = led[11] = 3; // 20% brightness
led[9] = led[10] = 2; // 10% brightness
The schematic isn't so bad I guess. I was just generally confused, but I'm starting to get my head around it now. Mostly I'm relieved that it was working all along and I didn't do some weird random screwup.What's confusing about the schematic? Is it the dark blue diagonal "floating" row line?
I'll see if I can do something while I'm "grinding" anyway.Can someone help me come up with a Cylon night-rider routine for that demo program? Something like a night rider but with trailing LEDs that fade? I would try to throw something together quickly but Helen's sister's wedding is tomorrow and we have to do rehersal and dinner and stuff so I'm a little short of time today.
Hi Eric,
No practical plans. This board was originally the prototype for a Serial Addressable Bar/Dot Display Controller which I used in a power management system to display Battery Capacity and Battery Load conditions.
Now the board is just a test bed, though it's been programmed a couple times to display staggered night rider patterns for a visiting niece or nephew (grin).
Regards, Mike
Couldn't be much simpler. If I'm screwing this up I'll sure be embarrassed.Send me your code so I can double check you?
k8lh(at)arrl.net
#include <system.h>
#include <boostc.h>
#pragma DATA _CONFIG, _MCLRE_ON&_WDT_OFF&_INTOSCIO
#pragma CLOCK_FREQ 8000000
unsigned char led[20]; // led matrix, pwm values 0..31
unsigned char shadow = 0; // isr, trisio shadow register
unsigned char colpos = 1; // isr, gpio column ring counter bit
unsigned char dcy = 15; // isr, duty cycle counter, 0..31
unsigned char dc0 = 0; // isr, row 0 (gp0) pwm value, 0..31
unsigned char dc1 = 0; // isr, row 1 (gp1) pwm value, 0..31
unsigned char dc2 = 0; // isr, row 2 (gp2) pwm value, 0..31
unsigned char dc3 = 0; // isr, row 3 (gp4) pwm value, 0..31
unsigned char addr = (unsigned char) &led;
#define end_of_period dcy.5 // isr, end of 32 pwm steps
#define end_of_cycle colpos.6 // isr, end of 5 column update cycle
void main()
{
unsigned char x,temp;
osccon = 0b01110001; // set 8 MHz INTOSC
cmcon0 = 7; // comparator off, digital I/O
ansel = 0; // a2d module off, digital I/O
trisio = 0b00111111; // set all pins to inputs
gpio = 0; // set all output latches to '0'
// setup 100 usec Timer 2 interrupts (8 MHz clock)
pir1 = 0; // clear peripheral interrupt flags
pie1 = 0; // clear peripheral interrupt enables
pie1.TMR2IE = 1; // set Timer 2 interrupt enable bit
tmr2 = 0; // clear Timer 2 register
t2con = 0b00000100; // '0-------' unimplemented bit
// '-0000---' TOUTPS<3:0>, postscale 1
// '-----1--' TMR2ON, turn Timer 2 on
// '------00' T2CKPS<1:0>, prescale 1
pr2 = 200-1; // 200 x 500-nsec 'ticks' = 100 usecs
intcon = 0b11000000; // '1-------' GIE, enable global ints
// '-1------' PEIE, enable peripheral ints
// '--0-----' T0IE, TMR0 ints disabled
// '---0----' INTE, off
// '----0---' GPIE, IOC disabled
// '-----000' T0IF/INTF/GPIF flags
// simple led interface to pwm driver, duty cycle values of 0..31
led[0] = led[19] = 0;
led[1] = led[18] = 0;
led[2] = led[17] = 0;
led[3] = led[16] = 0;
led[4] = led[15] = 0;
led[5] = led[14] = 0;
led[6] = led[13] = 0;
led[7] = led[12] = 0;
led[8] = led[11] = 0;
led[9] = led[10] = 0;
while(1){
led[0] = 2;
led[1] = 3;
led[2] = 5;
led[3] = 7;
led[4] = 9;
led[5] = 11;
led[6] = 14;
led[7] = 18;
led[8] = 23;
led[9] = 31;
delay_ms(200);
led[0] = 1;
led[1] = 1;
led[2] = 1;
led[3] = 1;
led[4] = 1;
led[5] = 1;
led[6] = 1;
led[7] = 1;
led[8] = 1;
led[9] = 1;
delay_ms(200);
}
}
/********************************************************************/
/* interrupt service routine */
/********************************************************************/
/* */
/* 100 usec Timer2 interrupts, 32 interrupts/column (3.2 msecs) */
/* for 32 pwm brightness levels. 160 interrupts (16 msecs) for a */
/* complete 5 column update cycle (62.5 Hz refresh rate). */
/* */
/* led array duty cycle parameter values of 0..31 produce actual */
/* duty cycles of 0% to 20% per LED in 0.625% (100 usec) steps. */
/* */
/* 57 to 84 cycles or approximately 42% "overhead" (8 MHz clock) */
/* */
/********************************************************************/
void interrupt()
{
if(dc0 == dcy) // if row 0 duty cycle match
shadow.0 = 0; // clear shadow bit (gp0)
if(dc1 == dcy) // if row 1 duty cycle match
shadow.1 = 0; // clear shadow bit (gp1)
if(dc2 == dcy) // if row 2 duty cycle match
shadow.2 = 0; // clear shadow bit (gp2)
if(dc3 == dcy) // if row 3 duty cycle match
shadow.4 = 0; // clear shadow bit (gp4)
dcy++; // increment duty cycle counter
asm{
movf _colpos,W
andwf _shadow,W // is the float bit required?
btfss _status,Z // no, skip, else
iorlw 0b00100000 // set the 'float' bit
iorwf _shadow,W // pick up led bits
iorwf _colpos,W // pick up column bit
xorlw 0b00111111 // invert all
movwf _trisio // update the column LEDs
}
if(end_of_period){ // if all 32 pwm steps complete
dcy = 0; // reset duty cycle counter
asm{
bcf _status,C // shift column bit mask
rlf _colpos,F
btfsc _colpos,3 // if gp3 bit position
rlf _colpos,F // shift to gp4 bit position
}
if(end_of_cycle){ // if all 5 columns have been updated
colpos = 1; // reset colpos bit to column 0
asm{ // reset led[] array address pointer
movlw _led
movwf _addr // addr = (unsigned char) &led
}
}
shadow = 0b00010111; // setup shadow (all row bits "on")
gpio = colpos; // setup output latch, only 1 bit high
fsr = addr; // setup new column pwm work variables
dc0 = indf; // row 0 (gp0) pwm value, 0..31
fsr++;
dc1 = indf; // row 1 (gp1) pwm value, 0..31
fsr++;
dc2 = indf; // row 2 (gp2) pwm value, 0..31
fsr++;
dc3 = indf; // row 3 (gp4) pwm value, 0..31
addr = fsr + 1; // save array address
}
}
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