issue with serin and serout

[oldcarguy85]

sorry i should have included more of the code. i already took care of turning everything to digital and turning the comparators off. made no difference. as i said the PIC communicates properly between two pc's. i connected one pc to the serial interface i have setup for the pic and then i used another max233 to connect another pc to my porta input and out and was able to send bytes between the pcs without a problem.

thanks,
Jordan

[mackrackit]

Looking back at your first post and I am still not clear on a few things.
ECU to PC = YES
PIC to PC = YES
ECU to PIC = NO

You may want to look at the PBP manual, I can not find 38400 as a baud rate and 6 is 9600 for SERIN/SEROUT.

o btw the ECU operates at 38400 baud rate thast why theres a 6 there.

Others have talked about using a PIC with an ECU, I have not done so, beyond basic serial com I can not help. So the best I can suggest at this point is to double check the baud rates and if the data is true or inverted.

[oldcarguy85]

i was under the impression teh baud rate was simply a calculation, (1000000 / baud) - 20


when i connected a PC to PORTA.0 and PORTA.1 it was able to send and recieve data at 38400 baud rate. actually now that u mention it, the one thing i DON't know is if the ECU wants the data true or inverted. i imagine true. how would i set it to inverted? the microcode reference suggests bit 14, but i'm confused how to set bit 14 ?

thanks,
Jordan

[mackrackit]

Here is some info on Baud Rate. http://francis.courtois.free.fr/jc1/...BitFormat.html
The formula you are looking at from the manual is for figuring bit time in microseconds.

In the back of the manual, Appendix A, there is a table for SREIN2/SEROUT2.

SERIN2 PORT?.?,84,[your DATA]

Will receive at 9600,Driven, True, no parity.

[mackrackit]

You got it while I was replying.
I do not think I was much help, Now I am confused
Would you mind posting the code that works so maybe I can learn something?

[oldcarguy85]

Well, it turns out i was wrong.

i only tested it for a few minutes this morning, and upon further inspection this afternoon it turns out, while i was recieving data, the data was completely inaccurate. im very confused. all i know is the ECU should talk at 38400 8N1. i've tried a LOT of combinations and i can't figure it out.

thanks,
Jordan

[oldcarguy85]

OK FINALLY GOT ITTT!!!!! WOO HOOO. forgot to connect a common ground! i am an idiot! btw - 6 works perfect for 38400 8N1!

thanks for the help
Jordan