From 76ced85569acd3f460559120ac9c029d90e81f1f Mon Sep 17 00:00:00 2001
From: Eggert Jung <eggert.s.jung@wischhof13.de>
Date: Thu, 20 May 2021 20:56:22 +0200
Subject: [PATCH] rewrite with minimal hd444780/modbus example

---
 i2c.c    |  61 +++++++++++++++++++++
 i2c.h    |  26 +++++++++
 lcd.c    | 187 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 lcd.h    |  46 ++++++++++++++++
 main.c   | 149 +++++++++++---------------------------------------
 makefile |   2 +-
 6 files changed, 354 insertions(+), 117 deletions(-)
 create mode 100644 i2c.c
 create mode 100644 i2c.h
 create mode 100644 lcd.c
 create mode 100644 lcd.h

diff --git a/i2c.c b/i2c.c
new file mode 100644
index 0000000..b484b73
--- /dev/null
+++ b/i2c.c
@@ -0,0 +1,61 @@
+/*
+ * i2c.c
+ *
+ * Created: 20.01.2018 12:50:54
+ *  Author: Ulrich
+ */ 
+
+#include "i2c.h"
+
+void i2c_init(void){
+	I2C_PORT |= (1 << SDA_PIN | 1 << SCL_PIN);			//Port Pullup
+	TWCR = 0;
+	TWSR = 0;
+	TWBR = ((F_CPU/SCL_CLOCK)-16)/2;
+	_delay_ms(50);
+}
+
+//***************************************************************************************
+uint8_t i2c_start (uint8_t addr){
+	uint16_t timeout = 0;
+
+    TWCR = (1 << TWINT | 1 << TWSTA | 1 << TWEN);
+    while(!(TWCR & (1<<TWINT))){
+	    if((timeout++) > 1000) return 1;
+	}
+    TWDR = addr;
+    TWCR = (1 << TWINT | 1 << TWEN);
+	timeout = 0;
+    while(!(TWCR & (1<<TWINT))){
+	    if((timeout++) > 1000) return 1;
+    }
+	return 0;
+}
+
+//***************************************************************************************
+uint8_t i2c_byte (uint8_t byte){  
+	uint16_t timeout = 0;
+    TWDR = byte;
+    TWCR = (1 << TWINT | 1 << TWEN);
+    while(!(TWCR & (1<<TWINT))){
+		if((timeout++) > 1000) return 1;
+	}
+	return 0;
+}
+
+//***************************************************************************************
+uint8_t i2c_readNak(void)
+{
+	uint16_t timeout = 0;
+	TWCR = (1<<TWINT) | (1<<TWEN);
+	while(!(TWCR & (1<<TWINT))){
+		if((timeout++) > 1000) return 0;
+	}
+    return TWDR;
+}
+
+//***************************************************************************************
+void i2c_stop (void){
+    TWCR = (1 << TWINT | 1 << TWSTO | 1 << TWEN);
+	TWCR = 0;
+}
diff --git a/i2c.h b/i2c.h
new file mode 100644
index 0000000..5ee4a34
--- /dev/null
+++ b/i2c.h
@@ -0,0 +1,26 @@
+/*
+ * i2c.h
+ *
+ * Created: 20.01.2018 12:51:11
+ *  Author: Ulrich
+ */ 
+
+#ifndef I2C_H_
+	#define I2C_H_
+
+	#include <avr/io.h>
+	#include <util/delay.h>
+	
+	//I2C
+	#define SDA_PIN			PC4 //PIN am Atmel
+	#define SCL_PIN			PC5 //PIN am Atmel
+	#define I2C_PORT		PORTC //PORT am Atmel
+	#define SCL_CLOCK		100000UL
+
+	void i2c_init(void);
+	uint8_t i2c_start (uint8_t);
+	uint8_t i2c_byte (uint8_t);  
+	uint8_t i2c_readNak(void);
+	void i2c_stop (void);
+
+#endif /* I2C_H_ */
\ No newline at end of file
diff --git a/lcd.c b/lcd.c
new file mode 100644
index 0000000..15d2f49
--- /dev/null
+++ b/lcd.c
@@ -0,0 +1,187 @@
+/*
+ * lcd.c
+ *
+ * Created: 20.01.2018 12:51:11
+ *  Author: Ulrich
+ */ 
+
+#include "lcd.h"
+
+volatile unsigned char char_counter = 0;
+
+// output data to lcd
+void lcd_out (unsigned char c) {
+	i2c_start(LCD_I2C_ADDR);
+	i2c_byte(c | LCD_BACKLIGHT);
+	i2c_stop();
+}
+
+//***************************************************************************************
+// CD = Command or Data
+void lcd_nibble_out(unsigned char c, unsigned char cd) {
+	unsigned char out = 0;
+	unsigned char rs = 0;
+	
+	if(cd) rs=LCD_RS;
+
+	//4 upper bits
+	if(c & (1<<4)) out |= LCD_D4;
+	if(c & (1<<5)) out |= LCD_D5;
+	if(c & (1<<6)) out |= LCD_D6;
+	if(c & (1<<7)) out |= LCD_D7;
+	lcd_out(out | rs | LCD_E);
+	_delay_ms(5);
+	lcd_out(out | rs);
+
+	//4 lower bits
+	out=0;
+	if(c & (1<<0)) out |= LCD_D4;
+	if(c & (1<<1)) out |= LCD_D5;
+	if(c & (1<<2)) out |= LCD_D6;
+	if(c & (1<<3)) out |= LCD_D7;
+	lcd_out(out | rs | LCD_E);
+	_delay_ms(5);
+	lcd_out(out | rs );
+}
+
+//***************************************************************************************
+// clear LCD
+void lcd_clear() {
+	lcd_nibble_out(0x01, 0); // clear display
+	lcd_nibble_out(0x80, 0);
+	char_counter = 0;
+}
+
+
+//***************************************************************************************
+// LCD home
+void lcd_home() {
+	lcd_nibble_out(0x80, 0);
+	char_counter = 0;
+}
+
+//***************************************************************************************
+// Init LCD
+void lcd_init() {
+	unsigned char loop=3;
+
+	while(loop--){
+		lcd_out(LCD_D4 | LCD_D5 | LCD_E);
+		_delay_ms(10);
+		lcd_out(LCD_D4 | LCD_D5);
+		_delay_ms(100);
+	}
+
+	// 4 bit mode
+	lcd_out(LCD_D5 | LCD_E);
+	_delay_ms(10);
+	lcd_out(LCD_D5);
+	_delay_ms(10);
+
+	lcd_nibble_out(0x28, 0);
+	lcd_nibble_out(0x0C, 0);
+
+	lcd_clear();
+}
+
+//***************************************************************************************
+void lcd_write_char (char c) {
+	if(char_counter == LCD_WIDTH) lcd_nibble_out(LCD_ADDR_LINE2,0);
+	if(char_counter == (LCD_WIDTH*2)){
+		lcd_nibble_out(LCD_ADDR_LINE1,0);
+		char_counter = 0;
+	}
+	char_counter++;
+	lcd_nibble_out(c, 1);
+}
+
+//***************************************************************************************
+void lcd_print_str(char *str) {
+	while (*str != 0){
+		if(char_counter == LCD_WIDTH) lcd_nibble_out(LCD_ADDR_LINE2,0);
+		if(char_counter == (LCD_WIDTH*2)){
+			lcd_nibble_out(LCD_ADDR_LINE1,0);
+			char_counter = 0;
+		}
+		char_counter++;
+		lcd_nibble_out(*str++, 1);
+	}
+}
+
+//***************************************************************************************
+void lcd_write_P (const char *Buffer,...)
+{
+	va_list ap;
+	va_start (ap, Buffer);	
+	
+	int format_flag;
+	char str_buffer[10];
+	char str_null_buffer[10];
+	char move = 0;
+	char Base = 0;
+	int tmp = 0;
+	char by;
+	char *ptr;
+		
+	//Ausgabe der Zeichen
+    for(;;){
+		by = pgm_read_byte(Buffer++);
+		if(by==0) break; // end of format string
+            
+		if (by == '%'){
+            by = pgm_read_byte(Buffer++);
+			if (isdigit(by)>0){                   
+ 				str_null_buffer[0] = by;
+				str_null_buffer[1] = '\0';
+				move = atoi(str_null_buffer);
+                by = pgm_read_byte(Buffer++);
+				}
+
+			switch (by){
+                case 's':
+                    ptr = va_arg(ap,char *);
+                    while(*ptr) { lcd_write_char(*ptr++); }
+                    break;
+				case 'b':
+					Base = 2;
+					goto ConversionLoop;
+				case 'c':
+					//Int to char
+					format_flag = va_arg(ap,int);
+					lcd_write_char (format_flag++);
+					break;
+				case 'i':
+					Base = 10;
+					goto ConversionLoop;
+				case 'o':
+					Base = 8;
+					goto ConversionLoop;
+				case 'x':
+					Base = 16;
+					//****************************
+					ConversionLoop:
+					//****************************
+					itoa(va_arg(ap,int),str_buffer,Base);
+					int b=0;
+					while (str_buffer[b++] != 0){};
+					b--;
+					if (b<move){
+						move -=b;
+						for (tmp = 0;tmp<move;tmp++){
+							str_null_buffer[tmp] = '0';
+							}
+						//tmp ++;
+						str_null_buffer[tmp] = '\0';
+						strcat(str_null_buffer,str_buffer);
+						strcpy(str_buffer,str_null_buffer);
+						}
+					lcd_print_str (str_buffer);
+					move =0;
+					break;
+				}
+		}else{
+			lcd_write_char (by);	
+		}
+	}
+	va_end(ap);
+}
\ No newline at end of file
diff --git a/lcd.h b/lcd.h
new file mode 100644
index 0000000..59ec513
--- /dev/null
+++ b/lcd.h
@@ -0,0 +1,46 @@
+/*
+ * lcd.h
+ *
+ * Created: 20.01.2018 12:51:11
+ *  Author: Ulrich
+ */ 
+
+#ifndef __LCD_H__
+	#define __LCD_H__
+
+	#include <inttypes.h>
+	#include <avr/io.h>
+	#include <avr/pgmspace.h>
+	#include <stdlib.h>
+	#include <stdarg.h>
+	#include <ctype.h>
+	#include <string.h>
+	#include <util/delay.h>
+	#include "i2c.h"
+
+	#define LCD_I2C_ADDR	0x4E
+
+	//Port Belegung am PCF8574 (1<<PORT)
+	#define LCD_RS			(1<<0)
+	#define LCD_RW			(1<<1)
+	#define LCD_E			(1<<2)
+	#define LCD_BACKLIGHT	(1<<3)
+
+	#define LCD_D4			(1<<4)
+	#define LCD_D5			(1<<5)
+	#define LCD_D6			(1<<6)
+	#define LCD_D7			(1<<7)
+
+	#define LCD_WIDTH 16
+	#define LCD_ADDR_LINE1	(0x80)
+	#define LCD_ADDR_LINE2	(0xC0)
+
+	void lcd_init(void);
+	void lcd_clear(void);
+	void lcd_home(void);
+	void lcd_print_str (char *str);
+	void lcd_write_P (const char *Buffer,...);
+
+	#define lcd_write(format, args...)   lcd_write_P(PSTR(format) , ## args)
+
+#endif
diff --git a/main.c b/main.c
index 86c6b93..92bd32f 100644
--- a/main.c
+++ b/main.c
@@ -1,140 +1,57 @@
+/*
+ * LCD_HD44780.c
+ *
+ * Created: 20.01.2018 12:51:11
+ *  Author: Ulrich
+ */ 
+
 #include <avr/io.h>
-#include <util/delay.h>
 #include <avr/interrupt.h>
+#include <util/delay.h>
 
+#include "lcd.h"
+#include "i2c.h"
 #include "modbus.h"
-#include "pid.h"
-#include "adc.h"
-#include "i2cmaster.h"
-
-void modbusGet(void);
-
-volatile uint16_t holdingRegisters[40];
-
-volatile float output;
-volatile struct pid controller;
-
-volatile float setpoint_1 = 130; 
-volatile float setpoint_2 = 150;
-volatile float setpoint_3 = 150;
-
-int main(){
-    DDRD |= (1 << 4); // LED
-    DDRD |= (1 << 3); // FU PWM
-    DDRD |= (1 << 2); // 485 DE
-
-    PORTD |= 1 << 4;
-
-    DDRB |= 0x0F; // out channels
-
-	PORTD|=(1<<0); // RX
-
-    // FU PWM on PD3
-    TCCR2A |= (1 << COM2B1) | (1 << COM2B0);
-    TCCR2A |= (1 << WGM21) | (1 << WGM20);
-    TCCR2B |= (1 << CS21);
-
-	modbusSetAddress(1);
-    modbusInit();
-
-    // Modbus Tick Timer
-    TCCR0B|=(1<<CS01); //prescaler 8
-	TIMSK0|=(1<<TOIE0);
-
-    initADC();
-    i2c_init();
-    sei();
-
-    _delay_ms(1000);
-    PORTD &= ~(1 << 4);
-    init_pid(&controller, 5, 0.2, 0);
 
-    // timer for regler
-    TCCR1B|=(1<<CS12) | (1<<CS10);
-	TIMSK1|=(1<<TOIE1)|(1<<OCIE1A);
-
-    while(1){
-	    modbusGet();
-    }
-}
+volatile uint16_t holdingRegisters[4];
 
 void modbusGet(void) {
 	if (modbusGetBusState() & (1<<ReceiveCompleted))
 	{
-		switch(rxbuffer[1]) {
+        switch(rxbuffer[1]) {
             case fcReadHoldingRegisters:
-				modbusExchangeRegisters(holdingRegisters,0,40);
-                break;
             case fcPresetSingleRegister:
-			case fcPresetMultipleRegisters: 
-				if(modbusRequestedAmount()==1) {
-                    modbusExchangeRegisters(holdingRegisters,0,40);
-                    if(modbusIsInRange(0))
-                        /* analog out for Motor VFD */
-                        OCR2B = holdingRegisters[0] & 0xFF;
-                    if(modbusIsInRange(1)){
-                        /* i2c scanner */
-                        for(int i = 0x0; i < 0xFF; i++){
-                            if(!i2c_start(i)){
-                                holdingRegisters[1] = i;
-                                i2c_stop();
-                                break;
-                            }
-                            i2c_stop();
-                        }
-                    }
-                } else {
-					modbusSendException(ecIllegalDataValue);
-				}
-                break;
-            case fcReadCoilStatus:
-            case fcForceSingleCoil:
-            case fcForceMultipleCoils:
-				modbusExchangeBits(&PORTB,0,4);
-                break;
-
-            case fcReadInputRegisters:
-                if(modbusRequestedAddress()<10)
-                    modbusExchangeRegisters((uint16_t *)&adc_avrg,0,8);
-                else
-                    modbusExchangeRegisters((uint16_t *)&output,10,4);
+            case fcPresetMultipleRegisters:
+                modbusExchangeRegisters(holdingRegisters,0,4);
+                lcd_home();
+                lcd_write("test %x", holdingRegisters[0]);
                 break;
-			
             default:
-				modbusSendException(ecIllegalFunction);
+                modbusSendException(ecIllegalFunction);
                 break;
 		}
 	}
 }
 
-ISR(TIMER0_OVF_vect) { //this ISR is called 9765.625 times per second
-	modbusTickTimer();
-}
-
-/* Heater PID control */
-ISR(TIMER1_OVF_vect) {
-    //output = pid_step(&controller, 1, setpoint_1 - adc_avrg[1]);
-    output = 1;
+int main(void)
+{
+	i2c_init();
+	lcd_init();
+	
+	lcd_clear();
 
-    //PORTD &= ~(1 << 4);
-
-    if(output > 128)
-        output = 128;
+    sei();
+    modbusSetAddress(1);
+    modbusInit();
 
-    if(output >= 1){
-        uint32_t tmp = output * 512;
-        if(tmp >= 0x10000)
-            tmp = 0xFFFE;
+    TCCR0B|=(1<<CS01); //prescaler 8
+	TIMSK0|=(1<<TOIE0);
 
-        OCR1A = tmp;
-        PORTB |= 0x0F;
-    }
-    else
-        OCR1A = 1000;
+	while(1){
+        modbusGet();
+	}
 }
 
-ISR(TIMER1_COMPA_vect) {
-    /* turn off outputs */
-    PORTB &= ~(0x0F);
+ISR(TIMER0_OVF_vect) { //this ISR is called 9765.625 times per second
+	modbusTickTimer();
 }
-
diff --git a/makefile b/makefile
index 6ea17af..e6c5f93 100644
--- a/makefile
+++ b/makefile
@@ -1,5 +1,5 @@
 TARGET  = main
-FILES   = main modbus buffer pid twimaster adc
+FILES   = main i2c lcd modbus
 MCU     = atmega328p
 PROGC	= m328p
 CC      = avr-gcc