| ??? 10/02/08 00:41 Read: times Msg Score: +1 +1 Good Question |
#158744 - weird output on LCD |
I made a circuit, and hooked up all 8 data pins (P1.0 through P1.7) of an AT89C2051 to pins 7 through 14 of the LCD. Everything seems to be ok, except that in certain cases, wrong characters are being printed.
for example, when I wanted to see "Mini FM Receiver", I see " Mioi!GM!Seceiwe". (yes, there's a space in front). so I checked the LCD datasheet, and I have come to the conclusion that the output of pin P1.0 is always high. I first tried using 10K pull-up resistors across all pins, and then I removed the 10K resistors, and I got the same results. I now tried to use a 10K pull-down resistor for P1.0 and I get the following text instead: "Lhnh FL Rdbdhvdr" So this makes me think that P1.0 needs to have a special resistor to it to satisfy my LCD. I could do the LCD in 4-bit mode, but this port (along with the rest of port 1) also drives a latch data input (chip: 74HC573) as well. Maybe I am overlooking something with port P1.0. can anyone help me? thanks. |
| Topic | Author | Date |
| weird output on LCD | 01/01/70 00:00 | |
| Welcome back | 01/01/70 00:00 | |
| try toggeling | 01/01/70 00:00 | |
| Timing | 01/01/70 00:00 | |
| some answers | 01/01/70 00:00 | |
| Phew. | 01/01/70 00:00 | |
inter-character delay | 01/01/70 00:00 | |
| Is 7/LCD connected to P1.0/'2051 at all? | 01/01/70 00:00 | |
| Check Hardware | 01/01/70 00:00 | |
| I had the same problem, ..... but solved | 01/01/70 00:00 |