Use a rs485 communication module

i do not put it online, for share (i'm lazy guy), i give it here...
the code is a bit confuse... it show all the alphabet char...
but draws a transition between chars (line by line with 20ms between each frame)...
but sure the code is working and draws chars on flipdot :)

[#include](https://forum.espruino.com/search/?q=%23include) <SoftwareSerial.h>

int compteurG = 0;
int compteur = 0;
int a = 0;
int ncar = 27;
boolean drapo = false;
byte lettreA[7], lettreB[7];

// assemble message
byte msg [11] = {
  0x80,    // start byte
  0x87,    // send byte and refresh
  0xFF,    // to all display adress
  0x01,    // first data thingy to display, is non printable ASCII
  0x01,
  0x01,
  0x01,
  0x01,
  0x01,
  0x01,
  0x8F     // end byte
};

byte charSet[][7] = {
  {0x0, 0x0, 0x18, 0x14, 0x14, 0x2e, 0x0},
{0x8, 0x14, 0x14, 0xc, 0x34, 0xa, 0x0},
{0x0, 0x0, 0x18, 0x4, 0x4, 0x3a, 0x0},
{0x8, 0x8, 0x8, 0xc, 0xa, 0x1c, 0x0},
{0x0, 0x0, 0x18, 0x1c, 0x4, 0x1a, 0x0},
{0x10, 0x28, 0x18, 0x8, 0xc, 0xa, 0x4},
{0x18, 0x1c, 0x10, 0x38, 0x14, 0x14, 0x8},
{0x8, 0x14, 0x14, 0xc, 0x14, 0x32, 0x0},
{0x8, 0x0, 0x8, 0x8, 0xc, 0x32, 0x0},
{0x8, 0x0, 0xc, 0x8, 0x18, 0xc, 0xc},
{0x0, 0x24, 0x14, 0xc, 0x14, 0x22, 0x0},
{0x8, 0x14, 0x14, 0x14, 0x8, 0x34, 0x0},
{0x0, 0x0, 0x0, 0x34, 0x2a, 0x2a, 0x0},
{0x0, 0x0, 0x0, 0x18, 0x14, 0x36, 0x0},
{0x0, 0x0, 0x58, 0x34, 0x24, 0x1a, 0x0},
{0x0, 0x0, 0x1c, 0x14, 0x1e, 0x24, 0x4},
{0x0, 0x0, 0x1c, 0x14, 0x3c, 0x12, 0x10},
{0x0, 0x0, 0x1c, 0xc, 0xc, 0x37, 0x0},
{0x0, 0x0, 0x8, 0x14, 0x12, 0x2c, 0x0},
{0x8, 0x3c, 0x8, 0x8, 0x8, 0x34, 0x0},
{0x0, 0x0, 0x0, 0x14, 0x14, 0x1e, 0x0},
{0x0, 0x0, 0x0, 0x34, 0x14, 0xa, 0x0},
{0x0, 0x0, 0x2a, 0x2a, 0x2a, 0x15, 0x0},
{0x0, 0x0, 0x14, 0x8, 0x14, 0x22, 0x0},
{0x0, 0xa, 0xa, 0xc, 0xc, 0xa, 0x4},
{0x0, 0x0, 0x3c, 0x10, 0x8, 0x3c, 0x0},
  {0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}
};

[#define](https://forum.espruino.com/search/?q=%23define) TX_ENABLE_PIN 3            // define the EIA-485 transmit driver pin
[#define](https://forum.espruino.com/search/?q=%23define) LED_PIN 13

// SoftwareSerial rs485(RO, DI);
SoftwareSerial rs485(4, 2); // pins on rs485 module ->

void setup() {
  pinMode(TX_ENABLE_PIN, OUTPUT);  // driver output enable
  rs485.begin (19200);              // vitesse com
  Serial.begin(9600);
  pinMode(LED_PIN, OUTPUT);
  // si pas de print softwareSerial ne fonctionne pas
  Serial.println("7x7 flipdots from Alfazeta");
}

void loop() {
  digitalWrite (TX_ENABLE_PIN, HIGH);     // enable transmit driver
  digitalWrite (LED_PIN, HIGH);
  
  // change les lettres tous les 7 tours
  // remplit les buffers de lettre pour anim de transition de caractère
  if (compteurG%7 == 0) {
    for (int i=0;i<7;i++){
      lettreA[i] = charSet[compteur%ncar][i];     // caractère avant
      lettreB[i] = charSet[(compteur+1)%ncar][i]; // caractère après
    }
    compteur++; // compteur du caractère à afficher dans charSet
  }
  
  for (int i = 3; i <= a%7+3; i++) { // nbr bits trame
    msg[i] = lettreB[i-3];
  }
  for (int i = a%7+4; i < 10; i++) { // nbr bits trame
    msg[i] = lettreA[i-3];
  }
  // envoie la séquence msg[] à l'afficheur
  for (int i = 0; i < 11; i++) {
    rs485.write(msg[i]);                // flip display print
    //Serial.print(msg[i],HEX);
    //Serial.print(" ");
  }
  //Serial.println();
  
  // gestion du buffer
  while (!(UCSR0A & (1 << UDRE0)))  // Wait for empty transmit buffer
    UCSR0A |= 1 << TXC0;  // mark transmission not complete
  while (!(UCSR0A & (1 << TXC0)));   // Wait for the transmission to complete

  digitalWrite(TX_ENABLE_PIN, LOW);       // disable transmit driver
  digitalWrite(LED_PIN, LOW);

  if (compteurG % 7 == 0) {
    // si lettre affichée au complet
    delay(700);
  } else {
    // si en cours de transition de lettre
    delay(20);
  }

  if (compteurG >= 7) { compteurG = 0; } else { compteurG ++;}
  if (a >= 7) { a = 0; } else { a ++;}
  if (compteur > ncar) { compteur = 0;}
}