Hi all, I am a retired domestic building and joinery contractor with newfound interests i.e, Arduino and a metal lathe. I read two posts about Arduino reading data from a digital caliper and connecting an LCD, both of them I tried with success and I added the two sample codes together with success printing the caliper reading on the LCD, this gave me the idea to read 2 digital calipers and printing the results to the LCD one above the other to use as a cheap digital display for my metal lathe. I have tried to amend the downloaded code to read from two sets of clock and data input pins and then print the results one above the other I have had some success printing on both lines but I am struggling to alter the read loop to switch the pair of alternate pairs of inputs pins after alternate reads prior to printing on the LCD.
I would be very grateful for any help from you more experienced coders with this project.
Thanks in anticipation.
papakel
Please post the full sketch of your best attempt to read both calipers.
If possible, you should always post code directly in the forum thread as text using code tags:
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/* Read the caliper data with Arduino and display mm or inch on serial monitor and LCD
Tutorial on: https://www.electronoobs.com/eng_arduino_tut93.php
Schematic: https://www.electronoobs.com/eng_arduino_tut93_sch1.php
Caliper | Arduino
GND (black) GND + 200 ohm
DAT (brown) D9
CLK (blue) D8
VCC 3.3V (red) 3.3V
LCD VSS GND
LCD VDD 5V+
LCD VO PIN3 VRES
LCD RS D12
LCD RW GND
LCD E D11
LCD D0
LCD D1
LCD D2
LCD D3
LCD D4 D5
LCD D5 D4
LCD D6 D3
LCD D7 D2
LCD A 5V+
LCD K GND
*/
#include <LiquidCrystal.h>
// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
int count;
void setup()
{
Serial.begin(115200);
#define CLOCK_PIN 8
#define DATA_PIN 9
//#define CLOCK1_PIN 6
//#define DATA1_PIN 7
count == 0;
; lcd.begin(1, 10);
}
char buf[10]; //;was20
unsigned long tmpTime;
int sign;
int inches;
long value;
float result;
bool mm = true; //define mm to false if you want inces values
void loop()
{
if (count == 0); (CLOCK_PIN == 8); (DATA_PIN == 9);
if (count == 1); (CLOCK_PIN == 6); (DATA_PIN == 7);
while (digitalRead(CLOCK_PIN) == LOW) {}
tmpTime = micros();
while (digitalRead(CLOCK_PIN) == HIGH) {}
if ((micros() - tmpTime) < 500) return;
readCaliper();
buf[0] = ' ';
dtostrf(result, 6, 3, buf + 1); strcat(buf, " in ");
dtostrf(result * 2.54, 6, 3, buf + 1); strcat(buf, " cm ");
if (mm)
{
if (count == 0)lcd.setCursor(0, 0); lcd.print(" Bed "); lcd.print(result); lcd.println(" mm ");
(count == 1); return;
if (count == 1);
lcd.setCursor(0, 1); lcd.print("C/SL "); lcd.print(result); lcd.println(" mm ");
(count == 0);
}
else
{
Serial.print(result); Serial.println(" in");
delay(100);
}
}
void readCaliper()
{
sign = 1;
value = 0;
inches = 0;
for (int i = 0; i < 24; i++) {
while (digitalRead(CLOCK_PIN) == LOW) {}
while (digitalRead(CLOCK_PIN) == HIGH) {}
if (digitalRead(DATA_PIN) == HIGH) {
if (i < 20) value |= (1 << i);
if (i == 20) sign = -1;
if (i == 23) inches = 1;
}
}
if (mm)
{
result = (value * sign) / 100.0;
}
else
{
result = (value * sign) / (inches ? 2000.0 : 100.0); //We map the values for inches, define mm to false if you want inces values
}
}
This includes my latest attempt to add a counter to change the clock and data pins but it does not work
papakel:
if (count == 0); (CLOCK_PIN == 8); (DATA_PIN == 9);
if (count == 1); (CLOCK_PIN == 6); (DATA_PIN == 7);
Problems:
Your if statement does nothing. Please take some time to read the reference page until you understand how to use it correctly:
You never follow an if statement with a semicolon.
ALWAYS use curly braces, even if the if block only contains a single line.
Don't smash multiple statements together on the same line. This just makes your code harder to read.
You are using the comparison operator (==) where you surely meant to use the assignment operator (=). Please take the time to read both these references until you understand how to use both operators correctly:
It appears your intent was to assign a value to a macro. You can't do that. Use a variable instead.
I think you would be better off to configure your readCaliper function so that it takes the clock and data pin as arguments. Put all the code to read the caliper in the readCaliper function. Make the readCaliper function return the read value instead of using the result global variable to transfer that information. Then you could do something like this:
lcd.print(readCaliper(caliperADataPin, caliperAClockPin));
Isn't that nice?
Slightly edited.
/* Read the caliper data with Arduino and display mm or inch on serial monitor and LCD
Tutorial on: https://www.electronoobs.com/eng_arduino_tut93.php
Schematic: https://www.electronoobs.com/eng_arduino_tut93_sch1.php
Caliper | Arduino
GND (black) GND + 200 ohm
DAT (brown) D9
CLK (blue) D8
VCC 3.3V (red) 3.3V
LCD VSS GND
LCD VDD 5V+
LCD VO PIN3 VRES
LCD RS D12
LCD RW GND
LCD E D11
LCD D0
LCD D1
LCD D2
LCD D3
LCD D4 D5
LCD D5 D4
LCD D6 D3
LCD D7 D2
LCD A 5V+
LCD K GND
*/
#include <LiquidCrystal.h>
// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
// Just keep all the numbers
#define CLOCK_PIN_1 6
#define DATA_PIN_1 7
#define CLOCK_PIN_0 8
#define DATA_PIN_0 9
int CLOCK_PIN = CLOCK_PIN_0;
int DATA_PIN = DATA_PIN_0;
int count;
char buf[10]; //;was20
unsigned long tmpTime;
int sign;
int inches;
long value;
float result;
bool mm = true; //define mm to false if you want inces values
/////////////////////////
void setup() {
Serial.begin(115200);
count = 0;
lcd.begin(1, 10);
pinMode(CLOCK_PIN_0, INPUT);
pinMode(DATA_PIN_0, INPUT);
pinMode(CLOCK_PIN_1, INPUT);
pinMode(DATA_PIN_1, INPUT);
}
/////////////////////////
void loop(){
if (count == 0){
CLOCK_PIN = CLOCK_PIN_0;
DATA_PIN = DATA_PIN_0;
}
if (count == 1){
CLOCK_PIN = CLOCK_PIN_1;
DATA_PIN = DATA_PIN_1;
}
while (digitalRead(CLOCK_PIN) == LOW) {}
tmpTime = micros();
while (digitalRead(CLOCK_PIN) == HIGH) {}
if ((micros() - tmpTime) < 500) {return;}
readCaliper();
buf[0] = ' ';
dtostrf(result, 6, 3, buf + 1);
strcat(buf, " in ");
dtostrf(result * 2.54, 6, 3, buf + 1);
strcat(buf, " cm ");
if (mm){
if (count == 0) {
lcd.setCursor(0, 0);
lcd.print(" Bed ");
lcd.print(result);
lcd.println(" mm ");
count = 1;
return;
}
if (count == 1){
lcd.setCursor(0, 1);
lcd.print("C/SL ");
lcd.print(result);
lcd.println(" mm ");
count = 0;
return;
}
} else {
Serial.print(result);
Serial.println(" in");
delay(100);
}
}
/////////////////////////
void readCaliper(){
sign = 1;
value = 0;
inches = 0;
for (int i = 0; i < 24; i++) {
while (digitalRead(CLOCK_PIN) == LOW) {}
while (digitalRead(CLOCK_PIN) == HIGH) {}
if (digitalRead(DATA_PIN) == HIGH) {
if (i < 20) value |= (1 << i);
if (i == 20) sign = -1;
if (i == 23) inches = 1;
}
}
if (mm) {
result = (value * sign) / 100.0;
} else {
result = (value * sign) / (inches ? 2000.0 : 100.0); //We map the values for inches, define mm to false if you want inces values
}
}
/////////////////////////
not sure I would be doing it that way, but anyway that gets the result is a Win.!
As pert mentioned you need to read about the various errors like the (==) and if(){dothis;}