Restart the javelin module

ChristianG

Is there a possibility to restart the javelin module from the application itself?
·
May be I'm paranoid? Or too much used to the ms platform? But can I really trust my application running for months or may be years, without a restart?
·
Christian

AllanL5

The big thing that takes large computer systems down (like windows) is memory leaks, or memory fragmentation.· Since the Javelin has no garbage collection, only allocate the objects you need, then use them over and over again.

The big thing that takes little computer systems down (like the BS2 and Javelin) is electrical noise.· Noise on the power supply lines, or RF noise from the air, makes life very difficult.· Sufficient capacitance on the voltage lines, and electrical shielding ( a grounded metal box around your circuit ) help to reduce or eliminate this.

Peter Verkaik

Dedicate one pin to reset the javelin.

Connect a 10k resistor from the pin to +5V.

Connect the pin to the reset pin.

At powerup/reset the pin will be an input·so this does not disturb

the reset circuitry.

In your application make the pin a low output. The javelin will

reset immediately then. (this makes the pin back an input)



To time the running application you can use the SoftRTC· class by

Jon Williams or the SoftwareRTC class by me.



regards peter

ChristianG

Thanks for good answers. I'm not sure I need to restart the module yet, but I notice that certain classes can overflow. For example will t = new Timer() overflow after 10,3 hours. I'm not sure what are the consequences of that, does it mean that the counter goes back to zero? do I need to create a new Timer-instance (and will a new Timer instance consume more memory), I have to test that...

Regards, Christian

Peter Verkaik

Yes, the timer count wraps to zero.

To keep longer times, timeout in say an hour and increment

an int, this gives you 65536 hours before overflow.



If you want to ensure the javelin keeps running,

put an external watchdog in your circuitry. Once the javelin

stops running or if you decide not to reset the watchdog,

the watchdog will timeout and will reset the javelin by means

of a low active pin connected to the javelin reset pin.



regards peter

ChristianG

I suppose that it means that the application have to send signals to the watchdog, when the application stops running the watchdog will reset the javelin.
Do you have more information about designing a watchdog?

Regards Christian

Peter Verkaik

Read here about Xicor X1227 rtc chip with builtin watchdog.
http://www.xicor.com/folders/X1227.php
I have written a class for the X1227 as I used it once.

Or check the Maxim MAX690 chip. This is useful for long timeouts:
·http://www.maxim-ic.com/quick_view2.cfm/qv_pk/1334/ln/en

regards peter



Post Edited (Peter Verkaik) : 9/16/2004 12:57:15 PM GMT

ChristianG

Thanks!!