PDA

View Full Version : Propeller rebooting



Don Pomplun
11-04-2011, 12:53 AM
My house control program (half a dozen objects) runs fine until there is a reboot (usually a power failure). When it comes back up, almost any input causes a restart. But if I plug in the USB cable to the PC and reload eeprom, it again works fine. Almost looks like an eeprom corruption, but I haven't gotten to the step of saving anything there yet. Any insight?
TIA
Don

Don Pomplun
11-04-2011, 12:57 AM
replying to my own thread, it suggested similar threads. One "solution" seems to be to umplug the prop plug. I'll do that.

Mike G
11-04-2011, 01:22 AM
Do you load the program into EEPROM by pressing the F11 key?

Loopy Byteloose
11-04-2011, 01:33 AM
Both EEPROMs and Flash Memory inside micro-controller may be sensitive to transients that would partially erase their contents.

Isolation from transients and good clean power supplies are likely solutions.

Don Pomplun
11-04-2011, 04:15 AM
Load program into eeprom with CTRL F11
Power supply is a big walwart. I'd be disappointed if eeprom were corrupted by transients!
Don

Loopy Byteloose
11-04-2011, 08:12 AM
I got the impression that older CNC machines with EEPROMs and flash memory have had trouble with this. Occasionaly, someone shows up on the forum looking for a way to reverse engineer the lost code in order to revive there machinery.

Of course, the environment they are working in has a lot of heavy inductive motors. And in a machine shop, electric welding adds to the hazard.

I just wonder if you are picking up transients from the AC interface that you have deployed.

Don Pomplun
11-04-2011, 03:11 PM
The *similar threads* seem to point to an FTID/USB interface problem. Hence the suggestion to unplug the Prop Plug. Way back when I bought a bunch of Propeller stuff (probably to get free shipping ;=), I got one Prop Plug, a few Propeller Dev Boards, and a couple of the original RS232 DB9 Prop Sticks.
Two questions:
Do the old Prop Sticks experience the alleged problem since they don't have the USB FTID interface?
Do the new USB Prop Sticks solve the problem?

TIA
Don

David Carrier
11-04-2011, 03:26 PM
Don,
If you have the Prop Plug is connected to a Propeller, but not connected to a USB port, make sure that you keep P30 and P31 low. If you set either pin high when the FT232RQ on the Prop Plug isn't receiving any power, the voltage on the FT232RQ's I/O pin will be much higher than its internal VCC. Any time the I/O pin voltage is more than 0.5 V above VCC, it can cause unintended behavior, including toggling DTR, which will reset the Propeller.

— David Carrier
Parallax Inc.

Don Pomplun
11-06-2011, 01:34 AM
OK, I'm just unplugging the Prop Plug now, and a couple intentional reboots seem to have been ok.

Still wondering about these two questions:
Do the old RS232 Prop Sticks experience the alleged problem since they don't have the USB FTID interface?
Do the new USB Prop Sticks solve the problem?

Phil Pilgrim (PhiPi)
11-06-2011, 01:33 AM
Do the old RS232 Prop Sticks experience the alleged problem since they don't have the USB FTID interface?
No, they do not suffer the same problem, since the RS232 interface is always energized.


Do the new USB Prop Sticks solve the problem?
Looking at the PropSTICK USB schematic (and not based on personal experience), I would have to say that it does not solve the problem. The main reason is that the connection between the FTDI chip and the Propeller is unbuffered. A proper 74LVC buffer would prevent the Propeller chip from powering the FT232R parasitically, which is the root cause of the problem:


http://forums.parallax.com/showthread.php?116711-Can-Parallax-do-something-about-the-FTDI-reset-bug&p=847328&viewfull=1#post847328

-Phil