Serial comms between A9 and M4

I'm experimenting with the serial communications between the A9 and M4. I have the code below running on the M4, and on the A9 I am using minicom -D /dev/ttyMCC to monitor the serial data. In minicom I see "foo" printed once or twice and that's it. It should be displaying every 2 seconds. The M4 is getting stuck in the call to serial.println() (indicated by the state of the BLINK_PIN). Any idea what I've got wrong here?

#include <SimpleTimer.h>

#define SERIAL_A9 Serial
#define BLINK_PIN 13

SimpleTimer send_timer;

void setup()
{
send_timer.setInterval(2000,sendRun);
SERIAL_A9.begin(115200);
pinMode(BLINK_PIN, OUTPUT);
delay(2000);
}

void loop() {
send_timer.run();
}

static void sendRun()
{
digitalWrite(BLINK_PIN, 1);
SERIAL_A9.println("foo");
digitalWrite(BLINK_PIN, 0);
}​

 

What is the source of the library SimpleTimer.h?

 

Note that a

Code:

digitalWrite(BLINK_PIN, 1);
SERIAL_A9.println("foo");
digitalWrite(BLINK_PIN, 0);

will blink the led so fast that your eyes won't be able to see it.

 

That's what should happen. But it's not. Instead, the LED is turning on and staying on.

 

SimpleTimer is just an arduino library for scheduling tasks. I don't think this is the source of the problem. I have simplified the code so that it now uses delays rather than SimpleTimer and the problem is still there. Here is the updated code;

#define SERIAL_A9 Serial
#define BLINK_PIN 13

void setup()
{
SERIAL_A9.begin(115200);
pinMode(BLINK_PIN, OUTPUT);
delay(2000);
}

void loop()
{
delay(2000);
digitalWrite(BLINK_PIN, 1);
SERIAL_A9.println("foo");
digitalWrite(BLINK_PIN, 0);
}

"foo" get printed a few times in minicom and then stops. The LED (BLINK_PIN) turns on and stays on indefinitely.

 

Could the issue be that I also have the udoofota-serial package installed? Will there be a conflict?

The serial comms looks fine when I monitor remotely in the Arduino Serial Monitor (via the virtual com port). But when I run minicom locally that's when the serial comms falls over.

 

I've uninstalled the udoofota-serial package using 'sudo apt remove udoofota-serial'. But I'm still seeing the serial data in my remote Arduino Serial Console. Is there something else that I need to do to disable this?

 

The issue only seems to occur when using minicom. If I access the serial port through a c program it works fine.

 

Strange, this should work without any problems.
What if you use the sketch from my IoT gateway How-To? http://www.udoo.org/forum/threads/how-to-make-udoo-neo-an-iot-gateway-of-sensors.6103/

What Udoobuntu version are you on?