{"id":1099,"date":"2015-04-06T18:00:55","date_gmt":"2015-04-06T22:00:55","guid":{"rendered":"https:\/\/ve2cuy.wordpress.com\/?page_id=1099"},"modified":"2015-04-06T18:00:55","modified_gmt":"2015-04-06T22:00:55","slug":"18f4620-2-x-i2c-lcd-with-pcf8574","status":"publish","type":"page","link":"https:\/\/ve2cuy.com\/blog\/index.php\/18f4620-2-x-i2c-lcd-with-pcf8574\/","title":{"rendered":"18F4620 – 2 x I2C LCD with PCF8574"},"content":{"rendered":"

To\u00a0my English language readers<\/h1>\n

The following article is in French.<\/p>\n

Here is a\u00a0summary:<\/p>\n

How to\u00a0display on a I2C LCD using a PCF8574 and a PIC 18F4620.<\/p>\n

The Proteus project is available here<\/a>.<\/p>\n

Note<\/strong>: source code is commented in English.<\/p>\n

\"18F4620<\/p>\n

\n

Mise en situation<\/h1>\n

Contrairement \u00e0 nos amis Arduiniens, quand vient le moment d\u2019interconnecter des p\u00e9riph\u00e9riques \u00e0 une puce PIC, c\u2019est souvent la recherche sans fin dans Internet.<\/p>\n

Pour Pic, moins de librairies sp\u00e9cialis\u00e9es comme : LiquidCrystal , Wire, Ethernet,\u00a0Firmata,\u00a0Servo,\u00a0WiFi,\u00a0TFT, EEPROM.<\/p>\n

Arduino supportant un nombre limit\u00e9 de puces, cela rend la normalisation des librairies plus simple.<\/p>\n

De plus, un grand nombre de contributeurs aident \u00e0 enrichir les outils de d\u00e9veloppement.<\/p>\n

De retour chez PIC<\/h1>\n

Parfois, interfacer une puce PIC \u00e0 un p\u00e9riph\u00e9rique est assez facile, LCD sous PIC<\/a>, d\u2019autres fois, pas vraiment.<\/p>\n

Tentez de trouver une solution pour connecter un \u00e9cran LCD en utilisant le protocole I2C via une puce PCF8574.<\/p>\n

Le genre de circuit\u00a0mille fois disponible sur eBay<\/a>.<\/p>\n

\"i2c<\/a><\/p>\n

Vrai, il existe des solutions \u00e0 gauche ou droite, mais quelle mis\u00e8re\u2026<\/p>\n

Pour en arriver \u00e0 une solution fonctionnelle, il faut ramer!<\/p>\n

Sc\u00e9nario 1<\/strong><\/p>\n

Le module PCF8574 n’est pas document\u00e9:<\/p>\n

ou est RS, CS, E?<\/p>\n

et pour le data?<\/p><\/blockquote>\n

Dans mon cas, j’ai du passer \u00e0 l’ohmm\u00e8tre les broches RS, RW,E et D4 \u00e0 D7 de mon afficheur I2C LCD made in China,<\/p>\n

R\u00e9sultat:<\/p>\n

Data PCA8574: P7,P6,P5,P4
\nControl: P3: Back Light, P2: E-Enable, P1:RW, P0: RS<\/p><\/blockquote>\n

Sc\u00e9nario 2<\/strong><\/p>\n

Vous avez trouvez un bout de code mais mis\u00e8re, pas le bon compilateur, la bonne famille ou le bon langage…<\/p>\n

Sc\u00e9nario 3<\/strong><\/p>\n

Vous avez la documentation en main et tout va bien, chanceux!<\/p>\n

Sc\u00e9nario 4<\/strong><\/p>\n

On vous fournit une solution – Proteus – \u00a0cl\u00e9 en main, possible? \u00a0Voir le lien de t\u00e9l\u00e9chargement au bas de l’article.<\/p>\n

<\/h1>\n

Fonctionnement de la plaquette I2C vers LCD<\/h1>\n

Les plaquettes de conversion des \u00e9crans LCD de I2C vers BUS LCD 4 bits utilisent, g\u00e9n\u00e9ralement, la puce PCF8574 ou la PCF8574A.<\/p>\n

Ce circuit a pour fonction de d\u00e9s\u00e9rialiser les donn\u00e9es du BUS I2C vers un octet donc, de pr\u00e9senter l’information en parall\u00e8le sur 8 bits.<\/p>\n

\"PCF8574\"<\/p>\n

Les \u00e9crans LCD HD44780 1602 pouvant \u00eatre op\u00e9r\u00e9s en mode 4 bits, il sera alors possible d\u2019utiliser une partie de l\u2019octet (nibble du bas) pour les signaux de contr\u00f4le : RS, RW, E, retro \u00e9clairage et l\u2019autre partie (nibble du haut) pour les donn\u00e9es.<\/p>\n

La difficult\u00e9 sera de combiner correctement les signaux de contr\u00f4le et les donn\u00e9es dans un m\u00eame octet.<\/p>\n

L’extraction des nibbles d’un octet de donn\u00e9es est habituellement obtenu ainsi:<\/p>\n

#define HI_NIBBLE(b) (((b) >> 4) & 0x0F)
\n#define LO_NIBBLE(b) ((b) & 0x0F)<\/p><\/blockquote>\n

\u00c9tant donn\u00e9 que les signaux de contr\u00f4le du LCD sont connect\u00e9s sur les broches P0 \u00e0 P3 du PCF8574 et les donn\u00e9es sur P4 \u00e0 P7, nous utiliseront plut\u00f4t l’approche suivante:<\/p>\n

#define LO_NIBBLE(b) (((b) << 4) & 0xF0)
\n#define HI_NIBBLE(b) ((b) & 0xF0)<\/p><\/blockquote>\n

Pour l’ajout des signaux de contr\u00f4le \u00e0 un des deux nibbles nous utiliseront des op\u00e9rations bit \u00e0 bit (Bitwise operation).<\/p>\n

Par example,<\/p>\n

lcddata = HI_NIBBLE(data) | LCD_BL | LCD_RS;<\/p><\/blockquote>\n

<\/h1>\n

Adresse I2C de PCF8574<\/h1>\n

L\u2019adresse I2C de PCF8574 est situ\u00e9e dans la plage 20H \u00e0 27H et de 38H \u00e0 3Fh pour PCF8574A.<\/p>\n

En utilisant ces deux puces dans un m\u00eame circuit, il serait possible de connecter 16 \u00e9crans LCD.<\/p>\n

Voici les tableaux d’adressage:<\/p>\n

\"PCF8574<\/a> \"PCF8574A<\/a><\/p>\n

Dans la cas des plaquettes que j\u2019utilise, les broches d\u2019adressage de PCF8674 (A0..A2) sont connect\u00e9es \u00e0 VCC via une r\u00e9sistance de tirage (pull-up resistor). \u00a0L\u2019adresse maximale de 27H est donc obtenue par d\u00e9faut.<\/p>\n

Il suffit de souder un cavalier sur les bornes A0..A2 pour ramener les broches \u00e0 0 et faire ainsi varier l\u2019adresse I2C du circuit.<\/p>\n

\"i2c<\/a><\/p>\n

<\/h1>\n

\u00c0 bien y regarder, pas si simple<\/h1>\n

M\u00eame si vous avez bien saisie l’arithm\u00e9tique des nibbles et les op\u00e9rations bit \u00e0 bit, ce n’est encore pas suffisant pour afficher sur l’\u00e9cran LCD. Pour ce faire, il faudra aussi comprendre la m\u00e9canique de programmation et la synchronisation des signaux de la puce contr\u00f4lant l’affichage: HD44780.
\nDans le code source du projet, il y a la s\u00e9quence suivante :<\/p>\n

void LCD_init(unsigned char addr)
\n{
\n__delay_ms(20); \/\/ Wait > 15 ms after power ON<\/p>\n

LCD_putcmd(addr, LCD_INIT_BYTE,0);__delay_ms(5); \/\/ Wait > 4.1 ms
\nLCD_putcmd(addr, LCD_INIT_BYTE,0);
\nLCD_putcmd(addr, LCD_INIT_BYTE,0);
\nLCD_putcmd(addr, LCD_BUS_WIDTH_4Bit,0);
\nLCD_putcmd(addr, LCD_4BITS_2LINES_5x8FONT,1);
\nLCD_putcmd(addr, LCD_DISPLAY_OFF_CURSOR_OFF_BLINK_OFF,1);
\nLCD_putcmd(addr, LCD_CLEAR,1);
\nLCD_putcmd(addr, LCD_INCREMENT_NO_SHIFT,1);
\nLCD_putcmd(addr, LCD_DISPLAY_ON_CURSOR_OFF,1);
\n} \/\/ LCD_init()<\/p><\/blockquote>\n

Ces instructions servent \u00e0 initialiser le LCD en mode 4 bits, \u00e0 allumer l’\u00e9cran, \u00e0 masquer le curseur, …<\/p>\n

Remarquez que des d\u00e9lais sont ins\u00e9r\u00e9s ici et l\u00e0. \u00a0Il y a des d\u00e9lais aussi dans la fonction LCD_putcmd.<\/p>\n

Ces d\u00e9lais sont importants pour assurer le bon fontionnement \u00a0de l’\u00e9cran.<\/p>\n

Pour conna\u00eetre les commandes de contr\u00f4les et les d\u00e9lais de programmation de la puce\u00a0HD44780, je vous revoie \u00e0 la documentation<\/a>.<\/p>\n

<\/h1>\n

Le projet<\/h1>\n

Apr\u00e8s deux jours de recherches et de prototypage, j’en suis arriv\u00e9 \u00e0 une solution de contr\u00f4le de deux (2) LCD via I2C\u00a0pilot\u00e9s par 2 puces PCF8574.<\/p>\n

Mes recherches, dans Internet, m’ont amen\u00e9 \u00e0 plusieurs endroits, mais la source d’information que j’ai retenue est situ\u00e9 \u00e0 l’adresse suivante: http:\/\/paulfjujo.free.fr\/_18FxxKxx\/Test_LCD_I2C_PIC18F26k22.htm<\/a>.<\/p>\n

Paul Freyer propose un\u00a0prototype\u00a0fonctionnel de l’utilisation d’une PCF8574.<\/p>\n

Je me suis inspir\u00e9 de son approche.<\/p>\n

Voici la solution:<\/p>\n

 <\/p>\n

\"18F4620<\/a>
\nT\u00e9l\u00e9charger<\/a>\u00a0le projet Proteus.<\/p>\n

\n

Les codes sources<\/h1>\n

main.c<\/h1>\n

[sourcecode language=\u00a0\u00bbc\u00a0\u00bb wraplines=\u00a0\u00bbfalse\u00a0\u00bb collapse=\u00a0\u00bbfalse\u00a0\u00bb]<\/p>\n

\/*
\n * File: main.c
\n * By: Alain Boudreault (ve2cuy)
\n * Date: 2015.04.04
\n * Completed: 2015.04.05
\n * —————————————————————————-
\n * Description: Use a PCA8574 to control 2 LCD using I2C protocol.
\n *
\n * Version fonctionnelle termin\u00e9e le 2015.04.05.
\n * —————————————————————————-
\n * standard I2C LCD from eBay
\n * http:\/\/www.ebay.com\/sch\/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR4.TRC2.A0.H0.Xi2c+lcd.TRS0&_nkw=i2c+lcd&_sacat=0
\n * LCD Data PCA8574: P7,P6,P5,P4
\n * LCD Control: P3: Back Light, P2: E-Enable, P1:RW, P0: RS
\n * —————————————————————————–
\n * This program is free software: you can redistribute it and\/or modify
\n * it under the terms of the GNU General Public License as published by
\n * the Free Software Foundation, either version 3 of the License, or
\n * (at your option) any later version.
\n *
\n * This program is distributed in the hope that it will be useful,
\n * but WITHOUT ANY WARRANTY; without even the implied warranty of
\n * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
\n * GNU General Public License for more details.
\n *
\n * You should have received a copy of the GNU General Public License
\n * along with this program. If not, see <http:\/\/www.gnu.org\/licenses\/>.
\n*\/<\/p>\n

#include <xc.h>
\n#include <stdio.h> \/\/ for sprintf()
\n#include "lcd.h" <\/p>\n

\/\/ #define proteus_simulation 1<\/p>\n

#pragma config OSC = INTIO7 \/\/ Internal osc
\n#pragma config WDT = OFF \/\/ No watch dog<\/p>\n

#define _XTAL_FREQ 8000000
\n#define TEXT_BUFFER 80<\/p>\n

char text[TEXT_BUFFER]; <\/p>\n

#ifdef proteus_simulation
\n char LCD_01_ADDRESS = 0x40;
\n char LCD_02_ADDRESS = 0x42;
\n#else
\n char LCD_01_ADDRESS = 0b1001110; \/\/ default address
\n char LCD_02_ADDRESS = 0b1001100; \/\/ jumper on A0
\n#endif<\/p>\n

void longDelay(int time){
\n for (int i = 0 ; i < time; i++) __delay_ms(50);
\n}<\/p>\n

\/\/ Program entry point
\nvoid main() {<\/p>\n

\/\/ADCON1 = 0xF; ADCON2 = 0xF; \/\/ No analog, all digital i\/o
\n OSCCON = 0b01110010; \/\/ Fosc = 8MHz
\n SSPADD = 19; \/\/ SCL (i2c clock) speed: ((8 Mhz) \/ (4 * 100 khz)) – 1 = 19
\n \/\/TRISC = 0xFF; PORTC = 0x00; LATC = 0x00;<\/p>\n

OpenI2C(MASTER, SLEW_OFF);
\n LCD_init(LCD_01_ADDRESS);
\n LCD_init(LCD_02_ADDRESS);<\/p>\n

unsigned int counter = 0;<\/p>\n

while(1) {
\n LCD_putcmd(LCD_01_ADDRESS, LCD_CLEAR,1);
\n sprintf(text, "%d times", counter++);
\n LCD_puts(LCD_01_ADDRESS, "I2C print on LCD 1\0");
\n LCD_goto(LCD_01_ADDRESS,2,1);
\n LCD_puts(LCD_01_ADDRESS, text);
\n LCD_goto(LCD_01_ADDRESS,3,1);
\n LCD_puts(LCD_01_ADDRESS, "——————–\0");
\n LCD_goto(LCD_01_ADDRESS,4,1);
\n LCD_puts(LCD_01_ADDRESS, "18F4620, PCF6574+LCD\0");
\n longDelay(10); <\/p>\n

LCD_putcmd(LCD_02_ADDRESS, LCD_CLEAR,1);
\n sprintf(text, "%u times", ~counter);
\n LCD_puts(LCD_02_ADDRESS, "I2C print on LCD 2\0");
\n LCD_goto(LCD_02_ADDRESS,2,1);
\n LCD_puts(LCD_02_ADDRESS, text);
\n LCD_goto(LCD_02_ADDRESS,3,1);
\n LCD_puts(LCD_02_ADDRESS, "——(cl)2015——\0");
\n LCD_goto(LCD_02_ADDRESS,4,1);
\n LCD_puts(LCD_02_ADDRESS, "Project by VE2CUY\0");
\n longDelay(10); <\/p>\n

} \/\/ while(1)
\n} \/\/ main()<\/p>\n

[\/sourcecode]<\/p>\n

<\/h1>\n
\n

lcd.h<\/h1>\n

[sourcecode language=\u00a0\u00bbc\u00a0\u00bb wraplines=\u00a0\u00bbfalse\u00a0\u00bb collapse=\u00a0\u00bbfalse\u00a0\u00bb]
\n\/*
\n * File: lcd.h
\n * Author: Alain Boudreault – ve2cuy
\n *
\n * Created on 6 avril 2015, 15:57
\n *
\n * —————————————————————————–
\n * This program is free software: you can redistribute it and\/or modify
\n * it under the terms of the GNU General Public License as published by
\n * the Free Software Foundation, either version 3 of the License, or
\n * (at your option) any later version.
\n *
\n * This program is distributed in the hope that it will be useful,
\n * but WITHOUT ANY WARRANTY; without even the implied warranty of
\n * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
\n * GNU General Public License for more details.
\n *
\n * You should have received a copy of the GNU General Public License
\n * along with this program. If not, see <http:\/\/www.gnu.org\/licenses\/>.
\n *\/<\/p>\n

#ifndef LCD_H
\n#define LCD_H<\/p>\n

#ifdef __cplusplus
\nextern "C" {
\n#endif<\/p>\n

#ifdef __cplusplus
\n}
\n#endif<\/p>\n

\/\/\/ ###### I2C LCD defines ######
\n#define LCD_WAIT_DELAY 2
\n#define LCD_BL 0x08
\n#define LCD_EN 0x04
\n#define LCD_RW 0x02
\n#define LCD_RS 0x01<\/p>\n

\/\/ LCD Command
\n#define LCD_INIT_BYTE 0x30
\n#define LCD_BUS_WIDTH_4Bit 0x20
\n#define LCD_BUS_WIDTH_8Bit 0x30
\n#define LCD_CLEAR 0x01
\n#define LCD_HOME 0x02
\n#define LCD_ON 0x0C
\n#define LCD_OFF 0x08
\n#define LCD_LINE1 0x80
\n#define LCD_LINE2 0xC0
\n#define LCD_LINE3 0x94
\n#define LCD_LINE4 0xD4
\n#define LCD_CURSOR_OFF 0x0C
\n#define LCD_UNDERLINE_ON 0x0E
\n#define LCD_BLINK_CURSOR_ON 0x0F
\n#define LCD_MOVE_CURSOR_LEFT 0x10
\n#define LCD_MOVE_CURSOR_RIGHT 0x14
\n#define LCD_SHIFT_LEFT 0x18
\n#define LCD_SHIFT_RIGHT 0x1E <\/p>\n

#define LCD_DISPLAY_ON_CURSOR_OFF 0x0c
\n#define LCD_DISPLAY_OFF_CURSOR_OFF_BLINK_OFF 0x08
\n#define LCD_4BITS_2LINES_5x8FONT 0x28
\n#define LCD_INCREMENT_NO_SHIFT 0x06
\n#define Byte unsigned char<\/p>\n

#define LO_NIBBLE(b) (((b) << 4) & 0xF0)
\n#define HI_NIBBLE(b) ((b) & 0xF0)<\/p>\n

\/\/ function prototypes
\nunsigned char I2C_PCF8574_Write(Byte Adr,Byte value);
\nvoid LCD_init(unsigned char addr);
\nvoid LCD_putcmd(unsigned char addr, unsigned char data,unsigned char cmdtype);
\nvoid LCD_putch(unsigned char addr, unsigned char data);
\nvoid LCD_puts(unsigned char addr, char *s);
\nvoid LCD_goto(unsigned char addr, char row, char column);<\/p>\n

#endif \/* LCD_H *\/<\/p>\n

[\/sourcecode]<\/p>\n

<\/h1>\n
\n

i2c_lcd.c<\/h1>\n

[sourcecode language=\u00a0\u00bbc\u00a0\u00bb wraplines=\u00a0\u00bbfalse\u00a0\u00bb collapse=\u00a0\u00bbfalse\u00a0\u00bb]
\n\/*
\n * File: i2c_lcd.c
\n * Author: Alain Boudreault – ve2cuy
\n *
\n * Created on 6 avril 2015, 15:57
\n * Note: Certains morceaux de code inspir\u00e9s de http:\/\/paulfjujo.free.fr\/_18FxxKxx\/datas\/18F26k22_LCD_PCF8574_I2C_Hardw_master_10Mhz.c
\n * —————————————————————————–
\n * This program is free software: you can redistribute it and\/or modify
\n * it under the terms of the GNU General Public License as published by
\n * the Free Software Foundation, either version 3 of the License, or
\n * (at your option) any later version.
\n *
\n * This program is distributed in the hope that it will be useful,
\n * but WITHOUT ANY WARRANTY; without even the implied warranty of
\n * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
\n * GNU General Public License for more details.
\n *
\n * You should have received a copy of the GNU General Public License
\n * along with this program. If not, see <http:\/\/www.gnu.org\/licenses\/>.
\n *\/<\/p>\n

#include <xc.h>
\n#include "lcd.h"<\/p>\n

#ifndef _XTAL_FREQ
\n#define _XTAL_FREQ 8000000
\n#endif
\n\/\/\/ ##############################################################################################
\n\/\/\/ Custom LCD_I2C functions<\/p>\n

unsigned char I2C_PCF8574_Write(Byte addr,Byte value)
\n{
\n unsigned char S,dummy;
\n StartI2C();
\n S = WriteI2C( addr );
\n if(S == -1) \/\/bus collision ?
\n {
\n dummy = SSPBUF; \/\/ clear the buffer,
\n SSPCON1bits.WCOL=0; \/\/ clear collision status bit
\n }
\n S = WriteI2C(value);
\n StopI2C();
\n \/\/ __delay_us(LCD_WAIT_DELAY); \/\/ No impact on my project!
\n return(S);
\n} \/\/ I2C_PCF8574_Write()<\/p>\n

void LCD_putcmd(unsigned char addr, unsigned char data,unsigned char cmdtype)
\n{
\n unsigned char lcddata; <\/p>\n

\/\/ Write high nibble
\n lcddata = HI_NIBBLE(data) |LCD_BL;
\n I2C_PCF8574_Write(addr,lcddata | LCD_EN);
\n I2C_PCF8574_Write(addr,lcddata & ~LCD_EN); \/\/ Reset LCD bus<\/p>\n

\/\/ cmdtype = 0; One cycle write, cmdtype = 1; Two cycle writes
\n if (cmdtype) {
\n \/\/ Write low nibble
\n lcddata = LO_NIBBLE(data) |LCD_BL;
\n I2C_PCF8574_Write(addr,lcddata | LCD_EN);
\n I2C_PCF8574_Write(addr,lcddata & ~LCD_EN); \/\/ Reset LCD bus
\n }
\n __delay_ms(2); \/\/ For most command, Wait > 100 us is ok.
\n} \/\/ LCD_putcmd())<\/p>\n

\/\/ Extract data high and low nible and send it to I2C LCD
\nvoid LCD_putch(unsigned char addr, unsigned char data)
\n{
\n unsigned char lcddata;
\n lcddata = HI_NIBBLE(data)|LCD_BL|LCD_RS; \/\/ Get high nibble
\n I2C_PCF8574_Write(addr,lcddata | LCD_EN); \/\/ Send it!
\n I2C_PCF8574_Write(addr,lcddata & ~LCD_EN); \/\/ Reset LCD bus
\n lcddata = LO_NIBBLE(data)|LCD_BL|LCD_RS; \/\/ Get low nibble
\n I2C_PCF8574_Write(addr,lcddata | LCD_EN); \/\/ Send it!
\n I2C_PCF8574_Write(addr,lcddata & ~LCD_EN); \/\/ Reset LCD bus
\n} \/\/ LCD_putch()<\/p>\n

\/\/ Init the LCD: DATA bus 4 bits, cursor off, auto increment, no shift.
\nvoid LCD_init(unsigned char addr)
\n{
\n __delay_ms(20); \/\/ Wait > 15 ms after power ON<\/p>\n

LCD_putcmd(addr, LCD_INIT_BYTE,0);__delay_ms(5); \/\/ Wait > 4.1 ms
\n LCD_putcmd(addr, LCD_INIT_BYTE,0);
\n LCD_putcmd(addr, LCD_INIT_BYTE,0);
\n LCD_putcmd(addr, LCD_BUS_WIDTH_4Bit,0);
\n LCD_putcmd(addr, LCD_4BITS_2LINES_5x8FONT,1);
\n LCD_putcmd(addr, LCD_DISPLAY_OFF_CURSOR_OFF_BLINK_OFF,1);
\n LCD_putcmd(addr, LCD_CLEAR,1);
\n LCD_putcmd(addr, LCD_INCREMENT_NO_SHIFT,1);
\n LCD_putcmd(addr, LCD_DISPLAY_ON_CURSOR_OFF,1);
\n} \/\/ LCD_init() <\/p>\n

\/\/ Goto line number. On line err, goto line 1.
\nvoid LCD_goto(unsigned char addr, unsigned char row, unsigned char column){
\n switch(row){
\n case 1: LCD_putcmd(addr,LCD_LINE1 + (column – 1), 1); break;
\n case 2: LCD_putcmd(addr,LCD_LINE2 + (column – 1), 1); break;
\n case 3: LCD_putcmd(addr,LCD_LINE3 + (column – 1), 1); break;
\n case 4: LCD_putcmd(addr,LCD_LINE4 + (column – 1), 1); break;
\n default: LCD_putcmd(addr,LCD_LINE1 + (column – 1), 1); break;
\n }
\n } \/\/ LCD_GOTO()<\/p>\n

\/\/ Note: The string must be zero terminated!
\n\/\/ Example: char callSign[] = "ve2cuy\0";
\nvoid LCD_puts(unsigned char addr, char *s)
\n{
\n int i=0;
\n while(*s != 0) LCD_putch(addr, *s++);
\n}<\/p>\n

[\/sourcecode]<\/p>\n

\n

Article r\u00e9dig\u00e9 par Alain Boudreault (ve2cuy) – Avril 2015 – Lien court<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

To\u00a0my English language readers The following article is in French. Here is a\u00a0summary: How to\u00a0display on a I2C LCD using a PCF8574 and a PIC 18F4620. The Proteus project is available here. Note: source code is commented in English. Mise en situation Contrairement \u00e0 nos amis Arduiniens, quand vient le moment d\u2019interconnecter des p\u00e9riph\u00e9riques \u00e0 […]<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"open","ping_status":"open","template":"","meta":{"footnotes":""},"class_list":["post-1099","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/ve2cuy.com\/blog\/index.php\/wp-json\/wp\/v2\/pages\/1099","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ve2cuy.com\/blog\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/ve2cuy.com\/blog\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/ve2cuy.com\/blog\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/ve2cuy.com\/blog\/index.php\/wp-json\/wp\/v2\/comments?post=1099"}],"version-history":[{"count":0,"href":"https:\/\/ve2cuy.com\/blog\/index.php\/wp-json\/wp\/v2\/pages\/1099\/revisions"}],"wp:attachment":[{"href":"https:\/\/ve2cuy.com\/blog\/index.php\/wp-json\/wp\/v2\/media?parent=1099"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}