Hello,
i was trying to synch my Arduinos for measuring applications. You can see the schematic in the attachments.
Here's the code from the Mega:
void setup() {
// put your setup code here, to run once:
Serial.begin(1200);
Serial1.begin(1200);
}
bool start = false;
char StartSignal = '\0';
char c = '\0';
byte go = 0b00000000;
byte ResetArduino = 0b00000000;
char RESARD = '\0';
void loop(){
while (start == false)
{
StartSignal = Serial.read();
if (StartSignal == '1')
{
//StartSignal = '\0';
start = true;
Serial1.println('L');
}
}
while (start == true)
{
if (Serial1.available())
{
go = Serial1.read();
c = go;
go = 0b00000000;
if (c == 'L')
{
c = '\0';
//dosomestuff
Serial.println('L');
Serial1.println('Z');
}
else if (c == 'Z')
{
c = '\0';
//dosomestuff
Serial.println('Z');
Serial1.println('L');
}
}
if (Serial.available())
{
ResetArduino = Serial.read();
RESARD = ResetArduino;
if (RESARD = '!')
{
//RESARD = '\0';
EmptyBuffer();
asm volatile (" jmp 0");
}
else{}
}
}
}
and this is the code from the Nano:
void setup() {
// put your setup code here, to run once:
Serial.begin(1200);
}
byte c = 0b00000000;
char arr = '\0';
void loop() {
// put your main code here, to run repeatedly:
if (Serial.available())
{
c = Serial.read();
arr = c;
c = 0b00000000;
if (arr == 'L')
{
arr = '\0';
Serial.println('L');
}
else if (arr == 'Z')
{
arr = '\0';
Serial.println('Z');
}
}
}
the idea of the code is to start the measurement with a '1' send to the mega and stop it with a '!'. yes i know that
Code: [Select]
asm volatile (" jmp 0");
isn't pretty but it works for me.
now, my problem is that i expect to recieve L and Z alternating. It works sometimes, but often i recieve two 'L' or 'Z' and i cant explain myself why this is happening. If i stop and restart the sketch with a '!' and a '1' and repeat it multiple times, i will recieve L's and Z's alternating but as long as I recieve two of each it means the Arduinos aren't perfectly synchronized.
Output looks like this:
(perfect synch)
L
Z
L
Z
L
Z
...
(not perfect)
L
L
Z
Z
L
L
Z
Z
...
Does anyone has an idea why this happens?
Moderator edit: image embedded in post
