4 / 6 digit display

[xygax]

LCD/module name

PCF85134

Controller

Other

Module details

Using a PCF85134 i have the following code i wrote myself but would benefit from inclusion into a suitable library its currently used as a clock via an esp8266 the code is below for the display driver. its a bit "raw" but functional

//----------------------------------------------------------------------------------------------------------------
//------------------------------------------Setup PCF 85134-------------------------------------------------------

void SetupPCF_Driver(byte _add){

byte _CMD = 0x80; // control the next byte is a command
byte _DTA = 0x40; // control the next byte is data
byte _LCMD = 0x00; // control the next byte is last command
byte _CFG1 = 0xC9; // configure as single static drive
byte _CFG2 = 0xF0; //
byte _CFG3 = 0xF8;

              Serial.print("\tWire Status: ");
//Wire.flush();
Wire.beginTransmission(_add);                   // I2C call the device
              Serial.print(Wire.status());                    // should return 0

    Wire.write(_CMD);
    Wire.write(_CFG1);
    Wire.write(_CMD);
    Wire.write(_CFG2);
    Wire.write(_LCMD);
    Wire.write(_CFG3);

Wire.endTransmission();
Serial.print(Wire.status());
LCD_connected = true;

Wire.beginTransmission(_add); // I2C
Wire.write(0x80); // command
Wire.write(0b11001101); // address (0) mode set
//Wire.write(0x80); // command
//Wire.write(0b11100000); // address (0) device select
Wire.write(0x80); // command
Wire.write(0b00000000); // address (0) data pointer
Wire.write(_DTA);
Wire.write(sevenSegCode(0x31));
Wire.write(sevenSegCode(0x32));
Wire.write(sevenSegCode(0x33));
Wire.write(sevenSegCode(0x34));
Wire.write(sevenSegCode(0x35));
Wire.write(sevenSegCode(0x36));
Wire.endTransmission();
Serial.print(Wire.status());

}

//----------------------------------------------------------------------------------------------------------------
void showIPByOctet(IPAddress ip, unsigned long waitMs ) {
char buf[5]; // 4 chars + null terminator

for (int i = 0; i < 4; i++) {
if (i < 3) {
snprintf(buf, sizeof(buf), "%03u-", ip[i]); // e.g. 192-
} else {
snprintf(buf, sizeof(buf), "%03u ", ip[i]); // e.g. 042
}
LCD_Segments(buf, segmentBuf);
segmentBuf[7] = 0xF0; // this is the loose leds top 4 bits
segmentBuf[8] = 0x00;
LCD_Output(segmentBuf); // and display
delay(waitMs);
}
}

void showIPScrolling(IPAddress ip, unsigned long waitMs) {
char ipStr[20]; // enough for "255-255-255-255 "
char window[5]; // 4 chars + null terminator

if (WiFi.localIP() == IPAddress(0,0,0,0)){
ip[0] = 192;
ip[1] = 168;
ip[2] = 004;
ip[3] = 001;

}

window[0] = '-';
if (WiFi.localIP() == IPAddress(0,0,0,0)){
window[1] = 'A';
} else{
  window[1] = 'I';
}
window[2] = 'P';
window[3] = '-';
window[4] = 0;
LCD_Segments(window, segmentBuf); 
segmentBuf[7] = 0xF0;                                   // this is the loose leds top 4 bits
segmentBuf[8] = 0x00;
LCD_Output(segmentBuf);                                 // and display
delay(1800);

// Build full IP string (zero-padded like your original)
snprintf(ipStr, sizeof(ipStr), "%03u-%03u-%03u-%03u ",
ip[0], ip[1], ip[2], ip[3]);

int len = strlen(ipStr);

// Repeat scroll 5 times
for (int repeat = 0; repeat < 3; repeat++) {

// Scroll across string
for (int pos = 0; pos < len; pos++) {

  // Build 4-character window
  for (int i = 0; i < 4; i++) {
    int idx = pos + i;

    if (idx < len) {
      window[i] = ipStr[idx];
    } else {
      window[i] = ' ';  // pad with spaces at end
    }
  }
  window[4] = '\0';

  // Display on LCD
  LCD_Segments(window, segmentBuf);
  segmentBuf[7] = 0xF0;
  segmentBuf[8] = 0x00;
  LCD_Output(segmentBuf);

  delay(waitMs);
}

}
}
//------------------------------------------set up the data for the LCD and send----------------------------------

uint8_t initBytes[32];

void LCD_Segments(const char *displayStr, uint8_t segmentByte[8]){

int i;                                            // counter
int digit;                                        // digit counter
int len;                                          // Input string length
uint8_t code;                                     // Seven segment code



for(i=0; i < 8; i++){                           // all good here 8 x 00
  segmentByte[i] = 0;                             // clear the output bytes
}

//Serial.print("\nD");
len = strlen(displayStr);                         // Length of input string

digit = 0;
for(i=0; i < len ; i++){                          // i is the digit counter
  
    if(displayStr[i] == '.')                      // Is this a period, and does this position have a period?
    { 
      if (state != CLOCK){
        segmentByte[digit-1] |= ( 1 << 0 );             // Set the period for the previous digit bit 7
      }

      
      if(state == CLOCK &&(Digits == 6||(Digits == 4 && digit == 2))){ 
        if (tm.tm_sec %2 != 0) {                        // flash the DP
        segmentByte[digit-1] |= ( 1 << 0 );             // Set the period for the previous digit bit 7 
        } 
      }                      
    }else{
    
      code = sevenSegCode(displayStr[i]);                      
      segmentByte[digit] |= code;                       // Set the segments to display this digit
      
      //Serial.print("   0x");
      //if (segmentByte[digit] < 16){Serial.print("0");}
      //Serial.print(segmentByte[digit],HEX);
      
      digit ++;
    }
}
return ;

}

void LCD_Output(uint8_t segmentByte[8]){
int j; // counter
//Serial.print("\tWire Status ");
Wire.flush();

  #ifdef  First
  Wire.beginTransmission(0x38);             // I2C

  #else
  Wire.beginTransmission(0x39);             // I2C

  #endif
  //Serial.print(Wire.status());
  
  Wire.write(0x80);           // command
  Wire.write(0b11001101);     // address (0) mode set
  //Wire.write(0x80);           // command
  //Wire.write(0b11100000);     // address (0) device select
  Wire.write(0x80);           // command
  Wire.write(0b00000000);     // address (0) data pointer
  //Wire.write(0x80);           // command
  //Wire.write(0b11111000);     // address (0) bank select
  //Wire.write(0x80);           // command
  //Wire.write(0b11110000);     // address (0) blink pointer
  Wire.write(0x40);           // data
  
  //Serial.print("\nI");
  for(j=0; j<8; j++){                       // j is the digit counter
    Wire.write(segmentByte[j]);
    delay(2);
  //Serial.print("   0x");
  //if (segmentByte[j] < 16){Serial.print("0");}
  //Serial.print(segmentByte[j],HEX);
        
  }
  Wire.endTransmission(); 
  //Serial.print("\tWire Status ");
  //Serial.print(Wire.status());

}

// sevenSegCode
//
// Given a hexadecimal digit, return the segment code that will
// display that digit on our LCD. Returns 0xff if digit is not valid.
//
uint8_t sevenSegCode(char c)
{
uint8_t code = 0;

switch(toupper(c))
{
    case ' ': code = 0x00; break;
    case '-': code = 0x40; break;
    case '0': code = 0x3F; break;
    case '1': code = 0x06; break;
    case '2': code = 0x5B; break;
    case '3': code = 0x4F; break;
    case '4': code = 0x66; break;
    case '5': code = 0x6D; break;
    case '6': code = 0x7D; break;
    case '7': code = 0x07; break;
    case '8': code = 0x7F; break;
    case '9': code = 0x6F; break;
    case 'A': code = 0x77; break;
    case 'B': code = 0x7C; break;
    case 'C': code = 0x39; break;
    case 'D': code = 0x5E; break;
    case 'E': code = 0x79; break;
    case 'F': code = 0x71; break;
    // "extended" chars
    case 'G': code = 0x6f; break;
    case 'H': code = 0x76; break;
    case 'I': code = 0x06; break;
    case 'J': code = 0x0e; break;
        //case 'K':
    case 'L': code = 0x38; break;
        //case 'M':
    case 'N': code = 0x54; break; // this one's a stretch
    case 'O': code = 0x3f; break;
    case 'P': code = 0x73; break;
        //case 'Q':
        //case 'R':
    case 'S': code = 0x6d; break;
    case 'T': code = 0x78; break; // eh? 
    case 'U': code = 0x3E; break;
        //case 'V':
        //case 'W':
        //case 'X':
    case 'Y': code = 0x6e; break;
        //case 'Z':

    default:
        code = 0xff; break;      // Invalid 
}

// if(code != 0xff) { // Was it a valid digit?
// code <<= 1; // Our segments are in upper 7 bits.
// }
// flip the byte
code = (code & 0xF0) >> 4 | (code & 0x0F) << 4;
code = (code & 0xCC) >> 2 | (code & 0x33) << 2;
code = (code & 0xAA) >> 1 | (code & 0x55) << 1;

return code;

}

Segment mapping progress

No response

Expected API

No response

Hardware access

I can test on real hardware

[petrkr]

So basically this is 'OneSeg' LCD, just with different controller?

[xygax]

Yes. The chip is a 60 segment single backplane i2c device so this implementation is 48 segments with single digit glass from Dongutech

https://www.dongutec.com/collections/segment-lcd/products/10pin-tn-positive-1-digit-segment-lcd-panel-static-drive-wide-temperature-segment-lcd-screen-3v-ht1621?data_from=collection_detail&spm=collection_detail.44918.collection_detail-2186833.34. and https://www.dongutec.com/collections/segment-lcd/products/28pin-tn-positive-large-1-digit-segment-lcd-panel-static-drive-wide-viewing-angle-wide-temperature-ht1621?data_from=collection_detail&spm=collection_detail.44918.collection_detail-2186833.54.

My module exposes the I2C on an RJ11 and has the option of an esp8266 on board. It has the ability to change the chip address so that two devices can be address on the same bus circuit is shown below :-

There is another available module that is smaller but features neopixel backlighting that also uses Dongutech glass

[petrkr]

I see.

Sad is it use deprecated esp8266. Much better will use esp32-s3 or maybe some Thread based h2, c6.

I guess this PCF could be compatible with PCF driverc which is already present here, so maybe it can be just derived class with few constants,. I'll check how it looks.

I see that board supports more type of one digits, but seems to be same setup like single drive.

Btw from scheme you have all address lines on ground, so you can not change it as you wrote. It would be nice have pcb jumper

I have 'break out board' for PCF

[xygax]

Yes it has an 8266 but it also has the i2c brought out so can be used with the 8266 either hi z or not mounted. If i was doing the same today i would have probably used a C6. the key thing i found is it needed a specific set of config commands to get the silicon in the right mode after that it was easy and there is a full alphabet generator (with a few gaps) that could be useful. circuit is a slightly older variant the I2c is link selectable on the rear of the pcb

[petrkr]

As long I do not have HW. I can not test implementation
https://github.com/petrkr/SegLCDLib/tree/pcf85134

here I did some refactor of PCF class and implemented 134 support, but only based on documentation and your code from this issue.

Implemented only RawLCD for it...

You can then be inspired by OneDigit LCD implementation in order to make SegLCD_Display_whateverrname.

I think about 2 possible ways

• do one class which will support all your LCDs on backlane, then name it generically
• do three classes for all cases and put name of variant to classname like MyBoard_Big4, MyBoard_Middle6, MyBoard_oneLCD (or what is that in middle)

[petrkr]

Implemented in develop branch for now. You can test it with example or with MenuControl