I have been working on this project again and made a bit of progress, If I have the Get_data part set correctly to receive the 14 bytes and I now have it displaying the - sign is I reverse the meter and + sign is correct way round, But the bit I don't understand is how to create the look up or down table to extract and print the first digit, the second,third and 4th I will need to add but it should be just a repeat of the first loop. At the moment I have an input voltage of 3.816 volts,
How do I extract the 3 out of first bytes 1&2 for the first digit ?
I know that the four digits begin at offsets 1, 3, 5 and 7 (sequences 0x2, 0x4, 0x6 and 0x8) within the frame.
The negative sign is encoded in the high bit of the first digit, and the decimal points are encoded in the high bits of the other three digits.
Here if the latest code
byte DMM_ARRAY[14]; // Where to store the Bytes read
int ledPin = 13; // Set the pin to digital I/O
int index = 0;
byte c;
byte TEMP1;
byte LOOKDOWN[7];
char temp2;
#include <LiquidCrystal_I2C.h>
#include <Wire.h>
LiquidCrystal_I2C lcd(0x03f, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE); // Set the LCD I2C address
void setup()
{
lcd.begin (20, 4); // for 16 x 2 LCD module
lcd.setBacklight(HIGH);
pinMode(ledPin, OUTPUT);
Serial.begin(2400);
}
void loop() {
Get_data();
//print the hex bytes to the display
lcd.setCursor(0, 0);
lcd.print(DMM_ARRAY[0], HEX);
lcd.print(",");
lcd.print(DMM_ARRAY[1], HEX);
lcd.print(",");
lcd.print(DMM_ARRAY[2], HEX);
lcd.print(",");
lcd.print(DMM_ARRAY[3], HEX);
lcd.print(",");
lcd.print(DMM_ARRAY[4], HEX);
lcd.print(",");
lcd.print(DMM_ARRAY[5], HEX);
lcd.print(",");
lcd.print(DMM_ARRAY[6], HEX);
lcd.print(",");
lcd.setCursor(0, 1);
lcd.print(DMM_ARRAY[7], HEX);
lcd.print(",");
lcd.print(DMM_ARRAY[8], HEX);
lcd.print(",");
lcd.print(DMM_ARRAY[9], HEX);
lcd.print(",");
lcd.print(DMM_ARRAY[10], HEX);
lcd.print(",");
lcd.print(DMM_ARRAY[11], HEX);
lcd.print(",");
lcd.print(DMM_ARRAY[12], HEX);
lcd.print(",");
lcd.print(DMM_ARRAY[13], HEX);
//'BYTES 1&2 FOR THE FIRST DIGIT AND PRINTS THE NEGATIVE SIGN
// For LOOP1 = 1 To 7 Step 2
for (int LOOP1 = 1; LOOP1 <= 7; LOOP1 += 2) {
TEMP1 = (DMM_ARRAY[1] << 4) | DMM_ARRAY[2] & 0x0F;
// If TEMP1.7 = 1 Then
if (TEMP1 & 0x80) {
lcd.setCursor(3, 3);
lcd.print("-"); //print - just to show it working
// Clear TEMP1.7 ' CLEAR THE MSB.
TEMP1 &= 0x80;
// Else Print At 2,1," "'Print $FE, $C0, " " 'PRINT BLANK SAPCE IF CORRECT
} else {
lcd.setCursor(3, 3);
lcd.print("+"); //print + just to show it working
// EndIf
}
for (int i = 0; i < sizeof LOOKDOWN; i++) {
if (LOOKDOWN[i] == TEMP1) {
TEMP1 = i;
//temp2[] ={ 0x7D, 0x05, 0x5B, 0x1F, 0x27, 0x3E, 0x7E, 0x15, 0x7F, 0x3F, 0 };
break;
}
}
}
}
void Get_data() {
while (Serial.available() < 14) {} // Wait 'till there are 14 Bytes waiting
for (int n = 0; n < 14; n++)
DMM_ARRAY[n] = Serial.read(); // Then: Get them.
}
with an input voltage of 3.816 volts the LCD displays
DMM_ARRARY 0,1,2,3,4,5,6,7 on the first line
15,29,3F,4F,5F,60,75
DMM_ARRARY 8,9,10,11,12,13,14 on the second line
83,9E,A0,B0,C0,D4,E8