/***********************************************************************
* HT1624.pde - Arduino demo program for Holtek HT1632 LED driver chip,
* As implemented on the Sure Electronics DE-DP016 display board
* (16*24 dot matrix LED module.)
* Nov, 2008 by Bill Westfield ("WestfW")
* Copyrighted and distributed under the terms of the Berkely license
* (copy freely, but include this notice of original author.)
*
* Adapted for 8x32 display by FlorinC.
***********************************************************************/
// comment out this line for the 8x32 display;
//#define _16x24_
#include
#include "ht1632.h"
#include
#include "font3.h"
#ifdef _16x24_
#define X_MAX 23
#define Y_MAX 15
#else
#define X_MAX 31
#define Y_MAX 7
#endif
//(fc) switched to a different set of pins than the original, to accomodate the SD shield;
#define HT1632_DATA 6 // Data pin (pin 7)
#define HT1632_WRCLK 7 // Write clock pin (pin 5)
#define HT1632_CS 8 // Chip Select (1, 2, 3, or 4)
#define plot(x,y,v) ht1632_plot(x,y,v)
#define cls ht1632_clear
#define DISPDELAY 0
char* msg = " Hello world";
int crtPos = 0;
/***********************************************************************
* ht1632_chipselect / ht1632_chipfree
* Select or de-select a particular ht1632 chip.
* De-selecting a chip ends the commands being sent to a chip.
* CD pins are active-low; writing 0 to the pin selects the chip.
***********************************************************************/
void ht1632_chipselect(byte chipno)
{
DEBUGPRINT("\nHT1632(%d) ", chipno);
digitalWrite(chipno, 0);
}
void ht1632_chipfree(byte chipno)
{
DEBUGPRINT(" [done %d]", chipno);
digitalWrite(chipno, 1);
}
/*
* we keep a copy of the display controller contents so that we can
* know which bits are on without having to (slowly) read the device.
* Note that we only use the low four bits of the shadow ram, since
* we're shadowing 4-bit memory. This makes things faster, and we
* use the other half for a "snapshot" when we want to plot new data
* based on older data...
*/
// (fc) covers the case for 32x8 as well (64 bytes, 4 bits)
byte ht1632_shadowram[96]; // our copy of the display's RAM
/*
* ht1632_writebits
* Write bits (up to 
to h1632 on pins HT1632_DATA, HT1632_WRCLK
* Chip is assumed to already be chip-selected
* Bits are shifted out from MSB to LSB, with the first bit sent
* being (bits & firstbit), shifted till firsbit is zero.
*/
void ht1632_writebits (byte bits, byte firstbit)
{
DEBUGPRINT(" ");
while (firstbit) {
DEBUGPRINT((bits&firstbit ? "1" : "0"));
digitalWrite(HT1632_WRCLK, LOW);
if (bits & firstbit) {
digitalWrite(HT1632_DATA, HIGH);
}
else {
digitalWrite(HT1632_DATA, LOW);
}
digitalWrite(HT1632_WRCLK, HIGH);
firstbit >>= 1;
}
}
/*
* ht1632_sendcmd
* Send a command to the ht1632 chip.
* A command consists of a 3-bit "CMD" ID, an 8bit command, and
* one "don't care bit".
* Select 1 0 0 c7 c6 c5 c4 c3 c2 c1 c0 xx Free
*/
static void ht1632_sendcmd (byte command)
{
ht1632_chipselect(HT1632_CS); // Select chip
ht1632_writebits(HT1632_ID_CMD, 1<<2); // send 3 bits of id: COMMMAND
ht1632_writebits(command, 1<<7); // send the actual command
ht1632_writebits(0, 1); /* one extra dont-care bit in commands. */
ht1632_chipfree(HT1632_CS); //done
}
/*
* ht1632_clear
* clear the display, and the shadow memory, and the snapshot
* memory. This uses the "write multiple words" capability of
* the chipset by writing all 96 words of memory without raising
* the chipselect signal.
*/
void ht1632_clear()
{
char i;
ht1632_chipselect(HT1632_CS); // Select chip
ht1632_writebits(HT1632_ID_WR, 1<<2); // send ID: WRITE to RAM
ht1632_writebits(0, 1<<6); // Send address
for (i = 0; i < 96/2; i++) // Clear entire display
ht1632_writebits(0, 1<<7); // send 8 bits of data
ht1632_chipfree(HT1632_CS); // done
for (i=0; i < 96; i++)
ht1632_shadowram[i] = 0;
}
/*
* ht1632_senddata
* send a nibble (4 bits) of data to a particular memory location of the
* ht1632. The command has 3 bit ID, 7 bits of address, and 4 bits of data.
* Select 1 0 1 A6 A5 A4 A3 A2 A1 A0 D0 D1 D2 D3 Free
* Note that the address is sent MSB first, while the data is sent LSB first!
* This means that somewhere a bit reversal will have to be done to get
* zero-based addressing of words and dots within words.
*/
static void ht1632_senddata (byte address, byte data)
{
ht1632_chipselect(HT1632_CS); // Select chip
ht1632_writebits(HT1632_ID_WR, 1<<2); // send ID: WRITE to RAM
ht1632_writebits(address, 1<<6); // Send address
ht1632_writebits(data, 1<<3); // send 4 bits of data
ht1632_chipfree(HT1632_CS); // done
}
void ht1632_setup()
{
pinMode(HT1632_CS, OUTPUT);
digitalWrite(HT1632_CS, HIGH); // unselect (active low)
pinMode(HT1632_WRCLK, OUTPUT);
pinMode(HT1632_DATA, OUTPUT);
ht1632_sendcmd(HT1632_CMD_SYSDIS); // Disable system
#ifdef _16x24_
ht1632_sendcmd(HT1632_CMD_COMS11); // 16*32, PMOS drivers
#else
// (fc)
ht1632_sendcmd(HT1632_CMD_COMS10); // 32x8, PMOS drivers
#endif
ht1632_sendcmd(HT1632_CMD_MSTMD); // Master Mode
ht1632_sendcmd(HT1632_CMD_SYSON); // System on
ht1632_sendcmd(HT1632_CMD_LEDON); // LEDs on
for (byte i=0; i<64; i++)
ht1632_senddata(i, 0); // clear the display!
delay(100); // ?
}
/*
* Copy a character glyph from the myfont data structure to
* display memory, with its upper left at the given coordinate
* This is unoptimized and simply uses plot() to draw each dot.
*/
void ht1632_putchar(int x, int y, char c)
{
// fonts defined for ascii 32 and beyond (index 0 in font array is ascii 32);
byte charIndex;
// replace undisplayable characters with blank;
if (c < 32 || c > 126)
{
charIndex = 0;
}
else
{
charIndex = c - 32;
}
// move character definition, pixel by pixel, onto the display;
// fonts are defined as one byte per row;
for (byte row=0; row<8; row++)
{
byte rowDots = pgm_read_byte_near(&myfont[charIndex][row]);
for (byte col=0; col<6; col++)
{
if (rowDots & (1<<(5-col)))
plot(x+col, y+row, 1);
else
plot(x+col, y+row, 0);
}
}
}
/*
* plot a point on the display, with the upper left hand corner
* being (0,0), and the lower right hand corner being (23, 15).
* Note that Y increases going "downward" in contrast with most
* mathematical coordiate systems, but in common with many displays
* No error checking; bad things may happen if arguments are out of
* bounds! (The ASSERTS compile to nothing by default
*/
void ht1632_plot (int x, int y, char val)
{
if (x<0 || x>X_MAX || y<0 || y>Y_MAX)
return;
char addr, bitval;
/*
* The 4 bits in a single memory word go DOWN, with the LSB
* (first transmitted) bit being on top. However, writebits()
* sends the MSB first, so we have to do a sort of bit-reversal
* somewhere. Here, this is done by shifting the single bit in
* the opposite direction from what you might expect.
*/
bitval = 8>>(y&3); // compute which bit will need set
#ifdef _16x24_
addr = (x<<2) + (y>>2); // compute which memory word this is in
#else
// (fc)
addr = (x<<1) + (y>>2); // compute which memory word this is in
#endif
if (val) { // Modify the shadow memory
ht1632_shadowram[addr] |= bitval;
}
else {
ht1632_shadowram[addr] &= ~bitval;
}
// Now copy the new memory value to the display
ht1632_senddata(addr, ht1632_shadowram[addr]);
}
/*
* get_shadowram
* return the value of a pixel from the shadow ram.
*/
byte get_shadowram(byte x, byte y)
{
byte addr, bitval;
bitval = 8>>(y&3); // compute which bit will need set
addr = (x<<2) + (y>>2); // compute which memory word this is in
return (0 != (ht1632_shadowram[addr] & bitval));
}
/*
* snapshot_shadowram
* Copy the shadow ram into the snapshot ram (the upper bits)
* This gives us a separate copy so we can plot new data while
* still having a copy of the old data. snapshotram is NOT
* updated by the plot functions (except "clear")
*/
void snapshot_shadowram()
{
for (char i=0; i< sizeof ht1632_shadowram; i++) {
ht1632_shadowram[i] = (ht1632_shadowram[i] & 0x0F) | ht1632_shadowram[i] << 4; // Use the upper bits
}
}
/*
* get_snapshotram
* get a pixel value from the snapshot ram (instead of
* the actual displayed (shadow) memory
*/
byte get_snapshotram(byte x, byte y)
{
byte addr, bitval;
bitval = 128>>(y&3); // user upper bits!
#ifdef _16x24_
addr = (x<<2) + (y>>2); // compute which memory word this is in
#else
// (fc)
addr = (x<<1) + (y>>2); // compute which memory word this is in
#endif
if (ht1632_shadowram[addr] & bitval)
return 1;
return 0;
}
/*
* This works equally well for both 16x24 and 8x32 matrices.
*/
void displayScrollingLine()
{
// shift the whole screen 6 times, one column at a time;
for (int x=0; x < 6; x++)
{
ht1632_putchar(-x, 0, msg[crtPos]);
ht1632_putchar(-x+6, 0, ((crtPos+1 < strlen(msg)) ? msg[crtPos+1] : ' '));
ht1632_putchar(-x+12, 0, ((crtPos+2 < strlen(msg)) ? msg[crtPos+2] : ' '));
ht1632_putchar(-x+18, 0, ((crtPos+3 < strlen(msg)) ? msg[crtPos+3] : ' '));
ht1632_putchar(-x+24, 0, ((crtPos+4 < strlen(msg)) ? msg[crtPos+4] : ' '));
ht1632_putchar(-x+30, 0, ((crtPos+5 < strlen(msg)) ? msg[crtPos+5] : ' '));
ht1632_putchar(-x+36, 0, ((crtPos+6 < strlen(msg)) ? msg[crtPos+6] : ' '));
delay(DISPDELAY);
}
crtPos++;
if (crtPos >= strlen(msg))
{
crtPos = 0;
}
}
/***********************************************************************
* traditional Arduino sketch functions: setup and loop.
***********************************************************************/
void setup ()
{
ht1632_setup();
Serial.begin(9600);
cls();
}
void loop ()
{
// display line;
displayScrollingLine();
}