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Semi-silly idea for you...but might be easier than you think. Might even be able to write a macro to handle the switching for you...Originally Posted by Kamikaze47
Use the HSEROUT for your serial out as you've already planned it out...
Get your hands on a couple of AND gates, or whatever works...
Use another PIC pin or two as STEERING LOGIC.
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Thats a pretty good idea.
"I think fish is nice, but then I think that rain is wet, so who am I to judge?" - Douglas Adams
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Well, heck, glad I could help...
Generally I'm useless
Does your program have any interrupts running in it?
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Actually, i do have 3 interrupts in this program. Maybe SEROUT is getting interrupted and thats messing with the data.
I'm gonna try disabling the interrupts while I run SEROUT... Not the best long term solution as It wouldnt be good to miss one of those interrupt events, but its worth a try to see if thats whats causing my problem.
"I think fish is nice, but then I think that rain is wet, so who am I to judge?" - Douglas Adams
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Are you using assembly int's (i.e. DT's fast ints) or the ON INTERRUPT types?
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I tried to test the interrupt theory with a simple GIE=0 before SEROUT and GIE=1 after it, but disabling the interrupts makes my program do unexpected things and makes it impossible to test. But i'd say its a high probability that the interrupts are the issue.
So I guess i'll have to stick with the hardware USART and, as skimask suggested, multiplex its output.
*edit*: Using ASM interrupts as timing is important.
Last edited by Kamikaze47; - 3rd March 2008 at 15:24.
"I think fish is nice, but then I think that rain is wet, so who am I to judge?" - Douglas Adams
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I've used serout and debug out to run to two different Double-Talk boards at 9600 baud, both performed perfectly, so I'd have to say that you're right, it's probably the interrupts. I tried it using two different LabX-Usb boards, with 18f4550's, with a DEFINE OSC 48. The boards have 20 Mhz crystals, and the oscillator selection is for HS_PLL.
Jerry.
If your oscilloscope costs more than your car...
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condition the data line first.
My serial data errors all went away as soon as I started presetting the data line before transmission.
For example, RS-232 defines the IDLE or MARK state to be negative volts at the RS-232 connector. That means positive volts at the PIC before the MAX232 inverter.
Try something like
HIGH TxData
pause 2
Serout/Serout2/Hserout your message.
It works for me.
HTH
BrianT
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BrianT: I previously tried a non-true driven mode and tied the line to +5 with a 10k resistor, which did not help reliability.
b1arrk5: Yep, in the end I did manage to test it with my interrupts disabled, and it worked, so thats the issue. Disabling the interrupts while I send isn't an option, so no software serial comms for me I guess.
"I think fish is nice, but then I think that rain is wet, so who am I to judge?" - Douglas Adams
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