First I want to thank anyone and everyone that writes and shares code. I just can't seem to get the hang of it. I'm great with hardware but coding just isn't my cup of tea. I've tried on and off for years.
My problem is my LCD connected through analog pins just won't show characters (I don't currently have an I2c for it). The back light and contrast function, I have quadruple checked my connections, verified (i believe) the pins are defined in the code, spent around 25 hours searching google and forums for a solution, and failing.
EDIT: I have verified the LCD works running "Hello World" off of the digital pins.
I then edited the code to below and it didn't work.
Do I need to define the analog pins as digital? If so how? I know it has something to do with digitalWrite() and digitalRead() but I don't understand how to do it.
/*
LiquidCrystal Library - Hello World
Demonstrates the use a 16x2 LCD display. The LiquidCrystal
library works with all LCD displays that are compatible with the
Hitachi HD44780 driver. There are many of them out there, and you
can usually tell them by the 16-pin interface.
This sketch prints "Hello World!" to the LCD
and shows the time.
The circuit:
* LCD RS pin to digital pin 12
* LCD Enable pin to digital pin 11
* LCD D4 pin to digital pin 5
* LCD D5 pin to digital pin 4
* LCD D6 pin to digital pin 3
* LCD D7 pin to digital pin 2
* LCD R/W pin to ground
* LCD VSS pin to ground
* LCD VCC pin to 5V
* 10K resistor:
* ends to +5V and ground
* wiper to LCD VO pin (pin 3)
Library originally added 18 Apr 2008
by David A. Mellis
library modified 5 Jul 2009
by Limor Fried (http://www.ladyada.net)
example added 9 Jul 2009
by Tom Igoe
modified 22 Nov 2010
by Tom Igoe
modified 7 Nov 2016
by Arturo Guadalupi
This example code is in the public domain.
http://www.arduino.cc/en/Tutorial/LiquidCrystalHelloWorld
*/
// include the library code:
#include <LiquidCrystal.h>
// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
///* LCD Constants */ Taken from Signal Generator
//#define LCD_D7 14 // A0
//#define LCD_D6 15 // A1
//#define LCD_D5 16 // A2
//#define LCD_D4 17 // A3
//#define LCD_E 19 // A5
//#define LCD_RS 5 // D5
const int rs = 5, en = 19, d4 = 17, d5 = 16, d6 = 15, d7 = 14;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// Print a message to the LCD.
lcd.print("hello, world!");
}
void loop() {
// set the cursor to column 0, line 1
// (note: line 1 is the second row, since counting begins with 0):
lcd.setCursor(0, 1);
// print the number of seconds since reset:
lcd.print(millis() / 1000);
}
this is for a function generator I've built i found here:
Arduino function gener.pdf (250.7 KB)
The code:
/*
* Portable Function Generator on Arduino v1.0
* Designed by Faransky, 2018
* Custom libraries are designed by:
* LiguidCrystal - Core Arduino library
* SPI - Core Arduino library
* Arduino pin change block - Generic example on the https://playground.arduino.cc/
* MD_AD9833 Library by MajCDesigns https://github.com/MajcDesigns/
* There is need to download the last library
*/
// include the library code:
#include <LiquidCrystal.h>
#include <SPI.h>
#include <MD_AD9833.h>
#include "pins_arduino.h"
/* Digital potentiometer constants */
#define DP_nINC 4 // D4
#define DP_UnD 3 // D3
#define DP_nCS 2 // D2
/* LCD Constants */
#define LCD_D7 14 // A0
#define LCD_D6 15 // A1
#define LCD_D5 16 // A2
#define LCD_D4 17 // A3
#define LCD_E 19 // A5
#define LCD_RS 5 // D5
/* Function generator constants */
#define DATA 11 // D11
#define CLK 13 // D13
#define FSYNC 10 // D10
/* Other pin definition constants */
#define VBAT 21 // A7
#define CAP_ON 18 // A4
#define CATHODE_PWM 9 // D9
/* Boolean Constants */
#define OFF false
#define ON true
/* Encoder constants */
#define ENC_A 8 // D8
#define ENC_B 7 // D7
#define ENC_SW 6 // D6
/* Encoder States */
#define UP 1
#define DOWN -1
#define SAME 0
/* Sequential state machine constants */
enum OutputConstants { NOFF = 1, SINE, TRIG, SQUARE };
enum States { StateOut = 1, StateAmplitude, Coupling, StateFreqHz, StateFreqKhz, StateFreqMhz, Brightness};
/* Custom LCD battery characters */
byte Bat0[8] = {0b01110, 0b11011, 0b10001, 0b10001, 0b10001, 0b10001, 0b10001, 0b11111};
byte Bat1[8] = {0b01110, 0b11011, 0b10001, 0b10001, 0b10001, 0b11111, 0b11111, 0b11111};
byte Bat2[8] = {0b01110, 0b11011, 0b10001, 0b11111, 0b11111, 0b11111, 0b11111, 0b11111};
byte Bat3[8] = {0b01110, 0b11111, 0b11111, 0b11111, 0b11111, 0b11111, 0b11111, 0b11111};
/* AD9833 & LCD Library objects definition */
MD_AD9833 AD(FSYNC);
MD_AD9833::channel_t chan;
MD_AD9833::mode_t mode;
LiquidCrystal lcd(LCD_RS, LCD_E, LCD_D4, LCD_D5, LCD_D6, LCD_D7);
/* Global state machine in-used variables */
unsigned char MenuState = StateOut; // Initial state
volatile uint8_t OutType = NOFF; // Output waveform type
volatile uint8_t DigiPotState = 0; // Digital potentiometer wiper state
volatile bool CouplingOn = true; // AC or DC coupling state
volatile uint8_t BrightnessState = 0; // LCD Backlight brightness state
/* Encoder pins state */
volatile bool encoder_A = false;
volatile bool encoder_B = false;
volatile bool encoder_A_prev = false;
/* Frequency states */
volatile uint32_t FreqHz = 0;
volatile uint32_t FreqKhz = 0;
volatile uint32_t FreqMhz = 0;
/* Function prototypes */
volatile uint8_t *port_to_pcmask[] = { &PCMSK0, &PCMSK1,&PCMSK2 };
static int PCintMode[24];
typedef void (*voidFuncPtr)(void);
volatile static voidFuncPtr PCintFunc[24] = { NULL };
volatile static uint8_t PCintLast[3];
void EnableInterrupts();
void DisableInterrupts();
void InitEncoder();
void InitOther();
void InitDigipot();
void CreateLcdChars();
byte ProcessBatteryVoltage();
void SetLcdBrightness(int brightness);
void PotDown();
void PotUp();
void InitPotState();
void InitDevice();
void SetADFrequency();
void SetADOutput();
void SetADOutType();
void BrightnessUp();
void BrightnessDown();
volatile int GetEncoderPos();
void EncoderPositionChanged();
void MainMenu();
/* Pin-change interrupts block */
/* /////////////////////////// */
void PCattachInterrupt(uint8_t pin, void (*userFunc)(void), int mode)
{
uint8_t bit = digitalPinToBitMask(pin);
uint8_t port = digitalPinToPort(pin);
uint8_t slot;
volatile uint8_t *pcmask;
// map pin to PCIR register
if (port == NOT_A_PORT) return;
else {
port -= 2;
pcmask = port_to_pcmask[port];
}
if (port == 1) slot = port * 8 + (pin - 14);
else slot = port * 8 + (pin % 8);
PCintMode[slot] = mode;
PCintFunc[slot] = userFunc;
*pcmask |= bit;
PCICR |= 0x01 << port;
}
void PCdetachInterrupt(uint8_t pin) {
uint8_t bit = digitalPinToBitMask(pin);
uint8_t port = digitalPinToPort(pin);
volatile uint8_t *pcmask;
// map pin to PCIR register
if (port == NOT_A_PORT) return;
else {
port -= 2;
pcmask = port_to_pcmask[port];
}
*pcmask &= ~bit;
if (*pcmask == 0) PCICR &= ~(0x01 << port);
}
static void PCint(uint8_t port) {
uint8_t bit;
uint8_t curr;
uint8_t mask;
uint8_t pin;
curr = *portInputRegister(port+2);
mask = curr ^ PCintLast[port];
PCintLast[port] = curr;
if ((mask &= *port_to_pcmask[port]) == 0) return;
for (uint8_t i=0; i < 8; i++) {
bit = 0x01 << i;
if (bit & mask) {
pin = port * 8 + i;
// Trigger interrupt if mode is CHANGE, or if mode is RISING and
// the bit is currently high, or if mode is FALLING and bit is low.
if ((PCintMode[pin] == CHANGE
|| ((PCintMode[pin] == RISING) && (curr & bit))
|| ((PCintMode[pin] == FALLING) && !(curr & bit)))
&& (PCintFunc[pin] != NULL)) {
PCintFunc[pin]();
}
}
}
}
/* Interrupt masking functions */
SIGNAL(PCINT0_vect) { PCint(0); }
SIGNAL(PCINT1_vect) { PCint(1); }
SIGNAL(PCINT2_vect) { PCint(2); }
/* End of pin-change interrupts block */
/* ////////////////////////////////// */
/* Enable/disable encoder pin interrupts */
void EnableInterrupts()
{
PCattachInterrupt(ENC_A, EncoderPositionChanged, CHANGE);
PCattachInterrupt(ENC_B, EncoderPositionChanged, CHANGE);
}
void DisableInterrupts()
{
PCdetachInterrupt(ENC_A);
PCdetachInterrupt(ENC_B);
}
void InitEncoder()
{
pinMode(ENC_A, INPUT);
pinMode(ENC_B, INPUT);
pinMode(ENC_SW, INPUT);
}
void InitOther()
{
pinMode(VBAT, INPUT_PULLUP);
pinMode(CAP_ON, OUTPUT);
pinMode(CATHODE_PWM, OUTPUT);
}
void InitDigipot()
{
pinMode(DP_nINC, OUTPUT);
pinMode(DP_UnD, OUTPUT);
pinMode(DP_nCS, OUTPUT);
}
void CreateLcdChars()
{
lcd.createChar(1, Bat0);
lcd.createChar(2, Bat1);
lcd.createChar(3, Bat2);
lcd.createChar(4, Bat3);
}
/* Process Li-ion battery voltage state and return appropriate character */
byte ProcessBatteryVoltage()
{
int BatVoltage = analogRead(VBAT);
//Serial.println(BatVoltage);
if (BatVoltage >= 950 && BatVoltage <= 1023) return (byte)4;
else if (BatVoltage >= 900 && BatVoltage < 950) return (byte)3;
else if (BatVoltage >= 850 && BatVoltage < 900) return (byte)2;
else {
//Serial.println("Encoder came here");
return (byte)1;
}
}
void SetLcdBrightness(int brightness)
{
analogWrite(CATHODE_PWM, brightness);
}
void PotDown()
{
for (uint8_t i = 0; i < 4; i++) {
digitalWrite(DP_UnD, LOW);
digitalWrite(DP_nINC, LOW);
delayMicroseconds(100);
digitalWrite(DP_nINC, HIGH);
delayMicroseconds(100);
if (DigiPotState <= 0) DigiPotState = 0;
else DigiPotState--;
}
}
void PotUp()
{
for (uint8_t i = 0; i < 4; i++) {
digitalWrite(DP_UnD, HIGH);
digitalWrite(DP_nINC, LOW);
delayMicroseconds(100);
digitalWrite(DP_nINC, HIGH);
delayMicroseconds(100);
if (DigiPotState >= 255) DigiPotState = 255;
else DigiPotState++;
}
}
void InitPotState()
{
digitalWrite(DP_nCS, LOW);
_delay_ms(10);
for (uint8_t i = 0; i < 255; i++) PotDown();
}
void InitDevice()
{
InitEncoder();
InitDigipot();
InitPotState();
InitOther();
Serial.begin(57600);
Serial.println("Serial logger is enabled");
lcd.begin(16, 2);
AD.begin();
}
void SetADFrequency()
{
uint32_t u1 = FreqHz + (FreqKhz * 1000) + (FreqMhz * 1000000);
chan = MD_AD9833::CHAN_0;
AD.setFrequency(chan, u1);
}
void SetADOutput()
{
chan = MD_AD9833::CHAN_0;
AD.setActiveFrequency(chan);
}
void SetADOutType()
{
switch (OutType)
{
case NOFF: mode = MD_AD9833::MODE_OFF; break;
case SINE: mode = MD_AD9833::MODE_SINE; break;
case TRIG: mode = MD_AD9833::MODE_TRIANGLE; break;
case SQUARE: mode = MD_AD9833::MODE_SQUARE1; break;
default: break;
}
AD.setMode(mode);
}
void setup() {
InitDevice();
CreateLcdChars();
SetADOutput();
pinMode(A4,OUTPUT);
digitalWrite(A4,HIGH);
mode = MD_AD9833::MODE_OFF;
AD.setMode(mode);
SetADFrequency();
BrightnessState = 127;
SetLcdBrightness(BrightnessState);
}
void BrightnessUp() {
if (BrightnessState >= 250) BrightnessState = 255;
else BrightnessState += 4;
SetLcdBrightness(BrightnessState);
}
void BrightnessDown() {
if (BrightnessState <= 5) BrightnessState = 0;
else BrightnessState -= 4;
SetLcdBrightness(BrightnessState);
}
volatile int GetEncoderPos()
{
volatile int RetVal = 0;
encoder_A = digitalRead(ENC_A);
encoder_B = digitalRead(ENC_B);
delay(10);
if((!encoder_A) && (encoder_A_prev)){
if(encoder_B) RetVal = 1;
else RetVal = -1;
}
else RetVal = 0;
encoder_A_prev = encoder_A; // Store value of A for next time
return RetVal;
}
void EncoderPositionChanged()
{
switch(MenuState) {
case StateFreqHz:
switch(GetEncoderPos()) {
case UP:
if (FreqHz >= 900) FreqHz = 900;
else FreqHz += 10;
break;
case DOWN:
if (FreqHz < 10) FreqHz = 0;
else FreqHz-= 10;
break;
default: break;
}
SetADFrequency();
break;
case StateFreqKhz:
switch(GetEncoderPos()) {
case UP:
if (FreqKhz >= 900) FreqKhz = 900;
else FreqKhz += 1;
break;
case DOWN:
if (FreqKhz <= 10) FreqKhz = 0;
else FreqKhz -= 1;
break;
default: break;
}
SetADFrequency();
break;
case StateFreqMhz:
switch(GetEncoderPos()) {
case UP:
if (FreqMhz >= 10) FreqMhz = 10;
else FreqMhz++;
break;
case DOWN:
if (FreqMhz <= 0) FreqMhz = 0;
else FreqMhz--;
break;
default: break;
}
SetADFrequency();
break;
case StateAmplitude:
switch(GetEncoderPos()) {
case UP: PotUp(); break;
case DOWN: PotDown(); break;
default: break;
}
break;
case StateOut:
switch(GetEncoderPos()) {
case UP:
if (OutType >= SQUARE) OutType = SQUARE;
else OutType++;
break;
case DOWN:
if (OutType <= NOFF) OutType = NOFF;
else OutType--;
break;
default: break;
}
SetADOutType();
break;
case Coupling:
switch(GetEncoderPos()) {
case UP: CouplingOn = true; break;
case DOWN: CouplingOn = false; break;
default: break;
}
digitalWrite(CAP_ON,CouplingOn);
break;
case Brightness:
switch(GetEncoderPos()) {
case UP: BrightnessUp(); break;
case DOWN: BrightnessDown(); break;
default: break;
}
break;
default: break;
}
}
void MainMenu()
{
MenuState = StateOut;
EnableInterrupts();
bool OutConfirm = false;
while(!OutConfirm)
{
switch(MenuState)
{
case StateFreqHz:
lcd.setCursor(0,0);
lcd.print("<Frequency: Hz >");
lcd.setCursor(0,1);
lcd.print("<Val:");
lcd.setCursor(5,1);
lcd.print(FreqHz);
if (FreqHz <= 9) {
lcd.setCursor(6,1);
lcd.print(" ");
}
else if (FreqHz > 9 && FreqHz <= 99) {
lcd.setCursor(7,1);
lcd.print(" ");
}
lcd.setCursor(8,1);
lcd.print("[Hz] >");
if (!digitalRead(ENC_SW)) {
while(!digitalRead(ENC_SW));
MenuState = StateFreqKhz;
}
break;
case StateFreqKhz:
lcd.setCursor(0,0);
lcd.print("<Frequency:KHz >");
lcd.setCursor(0,1);
lcd.print("<Val:");
lcd.setCursor(5,1);
lcd.print(FreqKhz);
if (FreqKhz <= 9) {
lcd.setCursor(6,1);
lcd.print(" ");
}
else if (FreqKhz > 9 && FreqKhz <= 99) {
lcd.setCursor(7,1);
lcd.print(" ");
}
lcd.setCursor(8,1);
lcd.print("[KHz] >");
if (!digitalRead(ENC_SW)) {
while(!digitalRead(ENC_SW));
MenuState = StateFreqMhz;
}
break;
case StateFreqMhz:
lcd.setCursor(0,0);
lcd.print("<Frequency:MHz >");
lcd.setCursor(0,1);
lcd.print("<Val:");
lcd.setCursor(5,1);
lcd.print(FreqMhz);
if (FreqMhz <= 9) {
lcd.setCursor(6,1);
lcd.print(" ");
}
else if (FreqMhz > 9 && FreqMhz <= 99) {
lcd.setCursor(7,1);
lcd.print(" ");
}
lcd.setCursor(8,1);
lcd.print("[MHz] >");
if (!digitalRead(ENC_SW)) {
while(!digitalRead(ENC_SW));
MenuState = Brightness;
}
break;
case StateAmplitude:
lcd.setCursor(0,0);
lcd.print("<Amplitude in %>");
lcd.setCursor(0,1);
lcd.print("<Value:");
lcd.setCursor(7,1);
lcd.print((DigiPotState*100)/255);
if ((DigiPotState*100)/255 <= 9) {
lcd.setCursor(8,1);
lcd.print(" ");
}
else if ((DigiPotState*100)/255 > 9 && (DigiPotState*100)/255 < 100) {
lcd.setCursor(9,1);
lcd.print(" ");
}
lcd.setCursor(10,1);
lcd.print(" [%] >");
if (!digitalRead(ENC_SW)) {
while(!digitalRead(ENC_SW));
MenuState = Coupling;
}
break;
case StateOut:
lcd.setCursor(0,0);
lcd.print("< Out Type >");
lcd.setCursor(0,1);
lcd.print("<Out:");
lcd.setCursor(5,1);
switch (OutType)
{
case NOFF: lcd.print("Off >"); break;
case SINE: lcd.print("Sine >"); break;
case TRIG: lcd.print("Triangle >"); break;
case SQUARE: lcd.print("Square >"); break;
default: break;
}
if (!digitalRead(ENC_SW)) {
while(!digitalRead(ENC_SW));
MenuState = StateAmplitude;
}
break;
case Coupling:
lcd.setCursor(0,0);
lcd.print("< Out Coupling >");
lcd.setCursor(0,1);
lcd.print("<Type:");
lcd.setCursor(6,1);
switch (CouplingOn)
{
case true: lcd.print(" [DC] >"); break;
case false: lcd.print(" [AC] >"); break;
default: break;
}
if (!digitalRead(ENC_SW)) {
while(!digitalRead(ENC_SW));
MenuState = StateFreqHz;
}
break;
case Brightness:
lcd.setCursor(0,0);
lcd.print("< Brightness >");
lcd.setCursor(0,1);
lcd.print("<Value:");
lcd.setCursor(7,1);
lcd.print((BrightnessState*100)/255);
if ((BrightnessState*100)/255 <= 9) {
lcd.setCursor(8,1);
lcd.print(" ");
}
else if ((BrightnessState*100)/255 > 9 && (BrightnessState*100)/255 < 100) {
lcd.setCursor(9,1);
lcd.print(" ");
}
lcd.setCursor(10,1);
lcd.print(" [%] >");
if (!digitalRead(ENC_SW)) {
while(!digitalRead(ENC_SW));
OutConfirm = true;
}
break;
}
delay(50);
}
DisableInterrupts();
}
void loop() {
/* Battery Character */
lcd.setCursor(15, 0);
lcd.write(ProcessBatteryVoltage());
/* Out State */
lcd.setCursor(0,0);
lcd.print("<Output:");
lcd.setCursor(8,0);
if (OutType != NOFF) lcd.print("ON ");
else lcd.print("OFF");
lcd.setCursor(11,0);
lcd.print(" > ");
/* Output Type */
lcd.setCursor(0,1);
lcd.print("<Y:");
lcd.setCursor(3,1);
switch(OutType) {
case NOFF: lcd.print("OFF "); break;
case SINE: lcd.print("SIN "); break;
case TRIG: lcd.print("TRN "); break;
case SQUARE: lcd.print("SQR "); break;
default: break;
}
/* Amplitude */
lcd.setCursor(7,1);
lcd.print("[A]:");
lcd.print((DigiPotState*100)/255);
if ((DigiPotState*100)/255 <= 9) {
lcd.setCursor(12,1);
lcd.print(" ");
}
else if ((DigiPotState*100)/255 > 9 && (DigiPotState*100)/255 < 100) {
lcd.setCursor(13,1);
lcd.print(" ");
}
lcd.setCursor(14,1);
lcd.print("%>");
if (!digitalRead(ENC_SW)) {
while(!digitalRead(ENC_SW));
MainMenu();
}
delay(50);
}
It will compile and only gives me 1 warning,
/tmp/.arduinoIDE-unsaved20221014-1926-5568nc.xw5mr/sketch_nov14a/sketch_nov14a.ino: In function 'void MainMenu()':
/tmp/.arduinoIDE-unsaved20221014-1926-5568nc.xw5mr/sketch_nov14a/sketch_nov14a.ino:578:16: warning: switch condition has boolean value [-Wswitch-bool]
switch (CouplingOn)
^
Sketch uses 9834 bytes (32%) of program storage space. Maximum is 30720 bytes.
Global variables use 749 bytes (36%) of dynamic memory, leaving 1299 bytes for local variables. Maximum is 2048 bytes.
It will also upload to my Nano with no problem (I'm guessing). IDE says upload complete.
I appreciate ant thoughts or insights you may have.
Solution:
I decided to make a second post simplifying what I believed to be my problem. (Search "Hello World" on analog pins). I was reminded in the comments about systematic troubleshooting. After following the instructions given, I knew part of what my problem was. I expanded on that and decided to go back and check all my wiring for the umpteenth time. Finding it all good I decided to check all my solder joints. I didn't have any bridges and everything looked good. I toned out all the connections from the Nano to the display and found no continuity between pin 14(A0) and the display. I then inspected the pins on my Nano and found a cold solder joint on, yep, pin 14 (A0). A little more flux and heat to reflow, upload the sketch and we're off to the races. I'm usually a pretty good solderer, I guess I got a little too excited and rushed a few of the joints. I ended up fixing 5 or so that looked suspect.
