ChibiOS Free Embedded RTOS

Posted: **Wed Sep 17, 2014 4:22 am**

Hi Guys,

I tried to seek help from the Arduino forum but no luck.
http://forum.arduino.cc/index.php?topic=266485.0

I have been running a ChibiOS/NIL on an ATmega32u4. It was super easy to implement my code. The moment I remove the USB and plug it back in, I break the bootloader! I am finish developping my code so I want a standalone module so I plug it in 12V. The moment I do that, I corrupt the bootloader. When developping, the USB cable is plug in the Arduino and I can upload my code and to all my test. The moment I remove the USB and try to apply external power again(USB, 5V, 12V, Vin, etc) it can not start. I have to reloader the bootloader, I connect to the serial port of the bootloader and reload the blink sketch.

I do not get this problem with the ATmega328. The problem is the same with the Arduino Micro.

I suppose that would be related to ATmega32u4 bootloader (Caterina). I think it might be ISR or watchdog that is continually resetting.

Here is a video of what is happening.
https://www.youtube.com/watch?v=lVY_4SOJBtE

Thank you for you help.

Posted: **Wed Sep 17, 2014 7:25 am**

Moving in the AVR forum, this is AVR-specific.

Giovanni

Posted: **Wed Sep 17, 2014 11:51 am**

To be more specific, I am not using avr gcc. I am compiling and uploading with Arduino IDE. I have try ChibiOS_AVR, NilRTOS and leOS/leOS2 libraries.
The bootloader is the Caterina that is use with the Arduino Micro, Arduino Leonardo and the Esplora.

Posted: **Wed Sep 17, 2014 2:45 pm**

This category of strange behavior tends to drive a developer insane

Two things I can think of:

1. did you compile with the correct arch for Caterina? According to the source I found here there's at least some requirement to compile with a #define __AVR_ATmega32U4__ in your code. Maybe you forgot it?

2. When flashing, does the programmer also set the fuses? Check that you flash with the correct target.

Posted: **Wed Sep 17, 2014 7:47 pm**

BOOM!

Found my bug Fred!
I deleted all my serial println and was able to pin point my mistake!!

I wanted to make a #define DEBUG where I could remove all my serial printf from my code instantly! To save memory.

Code: Select all

#define DEBUG 1 

#ifdef DEBUG
void SerialDebug(const char* sMsg){
     Serial.println(sMsg);
}
#endif

Then I use this

Code: Select all

 SerialDebug("thread1 thread initialize");

What killed the code is this: while (!Serial) {}

Code: Select all

 
void setup() {

  #ifdef DEBUG
    Serial.begin(9600);
    // wait for USB Serial
    while (!Serial) {}            <======= I deleted this line!
    SerialDebug("9600 baud rate");    
  #endif  
  
   
    
  // Start Nil RTOS.
  nilSysBegin();
  
  SerialDebug("Define is set");   
}

Thank you Fred.

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