Hi,
I'm developing a mod for Scratch that will allow controlling an educational robot via Bluetooth. I'm using SerialPort2 class that is included in Scratch plugin and allows opening ports by name. Everything works fine BUT, when I send commands in a loop, and the connection is lost (i.e. the robot was powered off), the VM freezes. I tried forking the port nextPutAll like that:
timer := Delay forMilliseconds: 1000. port := SerialPort2 new. port openPortNamed:'COM14' baud:57600. process := [port nextPutAll:'test'. Transcript show:'port'.] forkAt: 1. [timer wait. Transcript show:'delay'. process terminate.] forkAt: 7.
but with no result. Is there any way to write to a serial port with timeout?
mactro
-- View this message in context: http://forum.world.st/Serial-port-write-freezes-the-VM-tp4707333.html Sent from the Squeak - Beginners mailing list archive at Nabble.com.
On Mon, 9 Sep 2013, mactro wrote:
Hi,
I'm developing a mod for Scratch that will allow controlling an educational robot via Bluetooth. I'm using SerialPort2 class that is included in Scratch plugin and allows opening ports by name. Everything works fine BUT, when I send commands in a loop, and the connection is lost (i.e. the robot was powered off), the VM freezes. I tried forking the port nextPutAll like that:
timer := Delay forMilliseconds: 1000. port := SerialPort2 new. port openPortNamed:'COM14' baud:57600. process := [port nextPutAll:'test'. Transcript show:'port'.] forkAt: 1. [timer wait. Transcript show:'delay'. process terminate.] forkAt: 7.
but with no result. Is there any way to write to a serial port with timeout?
I can't help you with the SerialPort issue, but the process priorities 1 and 7 are definitely bad. Since the idle process uses priority 10, your processes will never run. Try using something between 11 and 39, or use the named priorities: Processor userBackgroundPriority Processor systemBackgroundPriority
Levente
mactro
-- View this message in context: http://forum.world.st/Serial-port-write-freezes-the-VM-tp4707333.html Sent from the Squeak - Beginners mailing list archive at Nabble.com. _______________________________________________ Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
Well, at first I tried using larger numbers, but it seems, that my VM has maximum priority equal to 8. Processor userBackgroundPriority prints 3 and Processor userInterruptPriority prints 5.
pozdrawiam Maciej Troszyński
2013/9/10 Levente Uzonyi leves@elte.hu:
On Mon, 9 Sep 2013, mactro wrote:
Hi,
I'm developing a mod for Scratch that will allow controlling an educational robot via Bluetooth. I'm using SerialPort2 class that is included in Scratch plugin and allows opening ports by name. Everything works fine BUT, when I send commands in a loop, and the connection is lost (i.e. the robot was powered off), the VM freezes. I tried forking the port nextPutAll like that:
timer := Delay forMilliseconds: 1000. port := SerialPort2 new. port openPortNamed:'COM14' baud:57600. process := [port nextPutAll:'test'. Transcript show:'port'.] forkAt: 1. [timer wait. Transcript show:'delay'. process terminate.] forkAt: 7.
but with no result. Is there any way to write to a serial port with timeout?
I can't help you with the SerialPort issue, but the process priorities 1 and 7 are definitely bad. Since the idle process uses priority 10, your processes will never run. Try using something between 11 and 39, or use the named priorities: Processor userBackgroundPriority Processor systemBackgroundPriority
Levente
mactro
-- View this message in context: http://forum.world.st/Serial-port-write-freezes-the-VM-tp4707333.html Sent from the Squeak - Beginners mailing list archive at Nabble.com. _______________________________________________ Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
beginners@lists.squeakfoundation.org
-
Levente Uzonyi -
Maciej Troszyński -
mactro