Noob cannot clear compiling error ['tc ' was not declared in this scope]

I’m building a reflow oven and the code is open source. The chip will be a atsamd21g. I have spent the last 2 days changing out libraries and searching the web, and with changes I made trying to fix things, changed but never cleared. I may have screwed things up in the program as I mentioned to the maker that I could not compile the program and his response was that he had no problem programming 100 chips with the program as is. This is a custom board that Adafruit said should be programmed as a Feather 0, but I have not gotten that far. I would appreciate any help given. It said not to post the hole file so I will only post the area which had the highlighted line. The hole file can be found at GitHub - UnexpectedMaker/ReflowMaster: Reflow Master is an open source Toaster Oven reflow controller that includes both hardware and software. if needed.

// Read the temp probe
void ReadCurrentTemp()
  int status =; This is the line the compiler highlighted!
#ifdef DEBUG
  Serial.print(" status: ");
  Serial.println( status );
  float internal = tc.getInternal();
  currentTemp = tc.getTemperature() + set.tempOffset;

The error when compiling is:

exit status 1
‘tc’ was not declared in this scope

Thanks for any help in advance.

Well, based on the snippet you posted, I’m with the compiler.

Thanks but I wish I could even find out what the error code means and how to address it! I can't even find anything that really addressed it when I google it!!!!! Thanks

Post the entire text of the error. It is easy. In the IDE there is a copy error message button in the lower right of the IDE window. Copy the error and paste it into a new post along with all of the code. Paraphrasing the error message leaves out important information. Posting snippets of code often leaves out the part of the code where the error really is.

In the github listing there's a declaration:


There is also an included library:

#include "MAX31855.h"

This requires this library to be installed:

Did you install that?

Thanks for the reply. I did install that library. At the top of the program he mentions all the libraries needed and in the error box on the bottom you can see that several of the libraries have many of the same names.
I was going to put the code in full below. The code is almost 2000 lines and that cannot be posted here. I did not do it at first as I read a moderator complaining about a noob doing just that. I tried and kept deleting to get you all I could untill it was rediculus how little you could see. Thanks again. I am new to programming and hope you can help me. I was able to attach the program file below and pasted more of the error code, but there is more of the same errors but more then the limit if I post all of it. I hope this helps.

C:\Users\Don\Documents\Arduino\Reflow_Master_trying_to_fix\Reflow_Master_trying_to_fix.ino:1781:16: warning: unused variable ‘xdiv’ [-Wunused-variable]

double ydiv, xdiv;


C:\Users\Don\Documents\Arduino\Reflow_Master_trying_to_fix\Reflow_Master_trying_to_fix.ino:1784:7: warning: unused variable ‘rot’ [-Wunused-variable]

int rot, newrot;


C:\Users\Don\Documents\Arduino\Reflow_Master_trying_to_fix\Reflow_Master_trying_to_fix.ino:1784:12: warning: unused variable ‘newrot’ [-Wunused-variable]

int rot, newrot;


C:\Users\Don\Documents\Arduino\Reflow_Master_trying_to_fix\Reflow_Master_trying_to_fix.ino: In function ‘char* string2char(String)’:

C:\Users\Don\Documents\Arduino\Reflow_Master_trying_to_fix\Reflow_Master_trying_to_fix.ino:1890:1: warning: control reaches end of non-void function [-Wreturn-type]


Multiple libraries were found for “Adafruit_ILI9341.h”
Used: C:\Users\Don\Documents\Arduino\libraries\Adafruit_ILI9341
Not used: C:\Users\Don\Documents\Arduino\libraries\Adafruit_ILI9341-master
Multiple libraries were found for “MAX31855.h”
Used: C:\Users\Don\Documents\Arduino\libraries\MAX31855
exit status 1
‘tc’ was not declared in this scope

ReflowMaster-master(1).zip (405 KB)

Can you just attach the ino file? I don’t want to download and open a zip file…

I will try to attach it. Sorry for taking so much of your time. Thanks for any help.

Reflow_Master.ino (46.8 KB)

Hooray! I went through all the lines in the errors one by one until it said it still had issues but did compile. Thanks to all that helped me. Now to see if the oven works!!