BigWumpus
- 20th April 2007, 09:23
...the last 14 days I was hunting a serious bug in our application...
today I found the solution !
A 16F872 works as a display-controller and receives the characters to print via I2C-communication. Until now, the characters are delivered very slowly, so the uC was able to put them on the display, before another character was received.
Now, I must store some characters and put them on the display, while other charaters are received via I2C. And here the trouble starts!
today I found out, the LCDOUT-command touches the TRIS each time, a character is given to the LCD (read-modify-write), so the TRIS-bits may become wrong (the MSSP switches the TRIS!)
So, I disables the switching of the TRIS in the LCDOUT-macro - it works !
today I found the solution !
A 16F872 works as a display-controller and receives the characters to print via I2C-communication. Until now, the characters are delivered very slowly, so the uC was able to put them on the display, before another character was received.
Now, I must store some characters and put them on the display, while other charaters are received via I2C. And here the trouble starts!
today I found out, the LCDOUT-command touches the TRIS each time, a character is given to the LCD (read-modify-write), so the TRIS-bits may become wrong (the MSSP switches the TRIS!)
So, I disables the switching of the TRIS in the LCDOUT-macro - it works !