TPIC6595?

[zeke 693]

Is anyone using the TPIC6595for their LED projects?

 

I'm about to do a digikey run and I'm looking a decent drive circuit for my 7-segment LED displays.

 

Thoughts or ideas?

[RobG 1,892]

I am using TPIC6C595 here and in another project (up to 8 digits/7 segment) which I didn't post here, but I am including the code below. It pretty much functions like 595 so you can connect in series.

Not sure if you are aware, but TI makes several types of this chip: A (TPIC6A595) with 350-mA outputs, B with 150-mA, and C with 100-mA.

 

This is a simple up counter with reset, first chip is 74hc595, second TPIC6C595. As you can see, there's nothing special about it.

#include 

#define DATAPIN BIT4
#define CLOCKPIN BIT5
#define LATCHPIN BIT0
#define UPSWITCH BIT2
#define CLEARSWITCH BIT1
#define SWITCHPINS (UPSWITCH + CLEARSWITCH)
#define NUMOFDIGITS 8

unsigned long counter = 0;                   // Counter variable
unsigned int digitCounter = 0;            // Digit counter
unsigned char digit = 0;               // Single digit to be displayed
unsigned char bcd7digit[10] = {0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F}; // BCD to 7 digit map
unsigned char digitSelector[8] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80}; // Digit selector map
unsigned int displayData = 0;
unsigned char shiftCounter = 0;

void main(void) {
   WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT

   P1DIR &= ~SWITCHPINS;   // port P1.2 and P1.1 input
   P1IE |= SWITCHPINS;// P1.2 and P1.1 interrupt enabled
   P1IES &= ~SWITCHPINS;// P1.2 and P1.1  lo/high edge
   //P1IES |= SWITCHPINS;// P1.2 and P1.1  high/lo edge
   P1IFG &= ~SWITCHPINS;// P1.2 and P1.1 IFG cleared
   P1REN |= SWITCHPINS;// resistor enable
   P1OUT &= ~SWITCHPINS;// pull down, since the switch will be active high
   //P1OUT |= SWITCHPINS;// pull up, since the switch will be active high

   P1OUT &= ~(CLOCKPIN + DATAPIN);
   P1OUT |= LATCHPIN;
   P1DIR |= LATCHPIN + CLOCKPIN + DATAPIN;

   CCTL0 = CCIE;                             // CCR0 interrupt enabled
   CCR0 = 250;                        //
   TACTL = TASSEL_2 + MC_1 + ID_3;           // SMCLK, upmode

   _bis_SR_register(LPM0_bits + GIE);        // Enter LPM0 w/ interrupt
}

// Timer A0 interrupt service routine
#pragma vector = TIMERA0_VECTOR
__interrupt void Timer_A (void) {
   digitCounter++;                       // Increase digit counter
   if(digitCounter == NUMOFDIGITS)
       digitCounter = 0;                // Mask, counter range
   digit = counter>>(4 * digitCounter);       // Shift digits right
   digit &= 0x0F;                      // Mask, we need first digit only

   displayData = digitSelector[digitCounter];
   displayData <<= 8;
   displayData |= bcd7digit[digit];
   shiftCounter = 0;
   while(shiftCounter < 16) {
       (displayData & BITF) ? (P1OUT |= DATAPIN) : (P1OUT &= ~DATAPIN);
       displayData <<= 1;
       P1OUT |= CLOCKPIN;
       P1OUT &= ~CLOCKPIN;
       shiftCounter++;
   }

   P1OUT &= ~LATCHPIN;                     // Latch data
   P1OUT |= LATCHPIN;
}

// Port 1 interrupt service routine
#pragma vector=PORT1_VECTOR
__interrupt void Port_1(void) {
   P1IE &= ~SWITCHPINS;               // disable P1.2 and P1.1 interrupt

   WDTCTL = WDT_MDLY_32;
   IFG1 &= ~WDTIFG;
   IE1 |= WDTIE;

   if(P1IFG & UPSWITCH) {
       counter = _bcd_add_long(counter, 0x01);
   } else if(P1IFG & CLEARSWITCH) {
       counter = 0;
   }
}

#pragma vector=WDT_VECTOR
__interrupt void WDT_ISR(void) {
   IE1 &= ~WDTIE;
   IFG1 &= ~WDTIFG;
   WDTCTL = WDTPW + WDTHOLD;
   P1IFG &= ~SWITCHPINS;
   P1IE |= SWITCHPINS;                  // enable P1.2 and P1.1 interrupt
}

[Mac 67]

I use them too Zeke. Nice chip. Similar to other serial-to-parallel 8-bit sinking drivers like the Micrel MIC5821 (500-ma). There are also a number of very nice 8-bit and 16-bit serial-to-parallel "constant current" sinking drivers you might look at (no current limiting resistors needed).

 

Cheerful regards, Mike