| ??? 09/08/09 08:46 Modified: 09/08/09 08:47 Read: times |
#168797 - Debug Tip: Always look for patterns! Responding to: ???'s previous message |
Jamie Gardner said:
I have no idea what is causing it Look at the symptoms, and see if you can spot any patterns; that will often lead you quite quickly to the cause - or, at least, significantly narrow-down the possible causes: letters like e for example shows on the lcd as the letter d So, is there a pattern here? What do you mean by letters "like" 'e' ? Look at the complete alphabet, and see if you can spot a pattern... For example: David Prentice said:
I agree with Jan. You should look for D0 being low if you get 0x64 ('d') for 0x65 ('e'). It is either an open circuit D0 if the HD44780 has internal pull-downs or a short to GND. For other debugging tips, see: http://www.8052.com/faqs/120313 |
| Topic | Author | Date |
| hd44780 16x2 lcd some letters display as other letters | 01/01/70 00:00 | |
| How fast is your 8051? | 01/01/70 00:00 | |
| speed | 01/01/70 00:00 | |
| incomplete init, or some hardware issue | 01/01/70 00:00 | |
| Looks like short between D0 and GND | 01/01/70 00:00 | |
| Pullup on D0 P0 | 01/01/70 00:00 | |
| Debug Tip: Always look for patterns! | 01/01/70 00:00 | |
| Oscilloscope | 01/01/70 00:00 | |
| will check D0 | 01/01/70 00:00 | |
| It could simply be open ... | 01/01/70 00:00 | |
| the analysis is fine... | 01/01/70 00:00 | |
It's easier if he has one ... | 01/01/70 00:00 |