| ??? 02/11/05 18:26 Read: times |
#87158 - Possibly Responding to: ???'s previous message |
Iztok Moravsek said:
In hardware manual is written, that UART levels are 0V(LOW) and 2.65V (HIGH) and on other hand is example to connect terminal to PC with MAX2323 or MAX2328 which has TTL/CMOS otput levels (0V,5V). - Can I connect 8052 Pins (0,5V) directly to the terminal ? Errr. The 2323 is a LNB mixer ! Do you mean the 3228 ?? The 3228 is designed to accept low level logic UP to 5V, so it will accept your 0-2.65 v from the modem. In fact it accepts 0-0.4 V as a logic 0 and 0.66 x Vl as logic one. The logic supply can also be different from the main supply too. I don't think you need a 3228 BUT do NOT connect directly to your 8052, without some kind of level conversion. If you are connecting directly from your chip to the modem, then you can probably use a simple diode clamp or a LV series buffer IC designed to be 5V tolerant on its inputs. I have not yet had to use sub 5V CPUs, but I am about to. Many others here have though and they'll be along directly.... Is for comunication to UART on terminal enough to connect RI,TI and GND signals ? Provided you can afford to turn off handshaking in the modem., yes. Steve |
| Topic | Author | Date |
| GSM Falcom C55 | 01/01/70 00:00 | |
| Read carefully | 01/01/70 00:00 | |
| Possibly | 01/01/70 00:00 | |
| Level translation | 01/01/70 00:00 | |
| Let's have a look | 01/01/70 00:00 | |
| Link | 01/01/70 00:00 | |
| Vmax | 01/01/70 00:00 | |
| Logic Levels | 01/01/70 00:00 | |
| Thanks, Level translation | 01/01/70 00:00 | |
just use the one suggested by Falcom | 01/01/70 00:00 |