SoftwareSerial problems

Submitted by Guest on Tue, 28/08/2012 - 18:00

Hello everybody:

Any known reason why SoftwareSerial can not be used in the NanodeRF if used as emonBase ?

I want to display the received data in a 7-Seg display using serial protocol and I can not make it works.

Tryied several different Digital Outputs available in my Nanode but none of them work, the software restarts each time attemps to write data to the SoftwareSerial port.

Any help will be welcome.

Thanks a million. Nelson.

Re: SoftwareSerial problems

Submitted by TrystanLea on Tue, 28/08/2012 - 18:05.

Hello Nelson, Im afraid I havent tried this, has anyone else?

Re: SoftwareSerial problems

Submitted by stuart on Tue, 28/08/2012 - 19:26.

I used the SoftSerial as part of my SMA PV interface software, might be of some use to you.

https://github.com/stuartpittaway/nanodesmapvmonitor

Re: SoftwareSerial problems

Submitted by nejemia (not verified) on Wed, 29/08/2012 - 12:23.

Thank you Stuart, Trystan:

I solved the problem but I'm afraid it is a very rudimentary solution.

Problem is with mySerial.print() statement - I've used mySerial.write() and I'm sending 1 Byte at a time to the Display and it works happy.

Weird, but... Learning the hard way.

Now, I'm facing another problem which involves RF12 module init.

Have 2 sketches which uses exactly the same init procedure, one works, the other does not...

I am using Trystan examples Fixed_Packets and Basic_multinode_webclient.

Fixed_Packets works, the other hungs at: if (rf12_recvDone() && rf12_crc == 0 && (rf12_hdr & RF12_HDR_CTL) == 0)

Never gets TRUE -

Well, lets continue working and thanks a lot !

Nelson.

Re: SoftwareSerial problems

Submitted by nejemia (not verified) on Wed, 29/08/2012 - 16:00.

Hello pal's:

I just detected the RF12 module has problems during initialization-

It hungs right after : rf12_initialize(10,RF12_433MHZ,210); // NodeID, Frequency, Group

Serial.println("Inicia RF12");

Main problem: this failure is not always, with some sketches it works with some others doesn`t ...

Any ideas? Suggestions ?

Thanks a lot --

Nelson.

Re: SoftwareSerial problems

Submitted by robinsmh (not verified) on Thu, 30/08/2012 - 09:00.

I'm not sure about the Nanode, but on the emonGLCD, the standard PV sketch uses nearly all the available memory (which is only 1K max to start with!) so any extra global variables or extra libraries added tend to make it crash in wierd and unpredictable ways.

There's a forum thread here which describes how to measure free memory:

http://forum.pololu.com/viewtopic.php?f=10&t=989&view=unread#p4218

Here's their code:

extern void __bss_end;
extern void *__brkval;

int get_free_memory()
{
int free_memory;

if((int)__brkval == 0)
free_memory = ((int)&free_memory) - ((int)&__bss_end);
else
free_memory = ((int)&free_memory) - ((int)__brkval);

return free_memory;
}

This returns the free bytes between heap and stack. If the stack grows doen to meet th heap (or static data) then it will crash. Maybe that's the problem here?

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