| ??? 01/13/07 17:31 Read: times |
#130774 - AT89C55WD UART voltages. |
Until 2nd January, I had no idea what an 8051, (etc.), was. I am a software engineer, forced, by lack of staff to look at some hardware issues.
In particular, our project involves the replacing of 4bit parallel driven 433 packet radio module with a serial Bluetooth module. Looking at the spec sheet for the AT89C55WD which is on the PCB, the UART I/O lines, RXD and TXD look to be logic level, i.e. 5V, whereas the UART on the Bluetooth module wants 3.3V and dies above 3.7V. Simple question, is that right? Are the I/O lines providing/requiring 5V, or is that a real UART in there giving/wanting nominally 3.3V? I assume I can use a couple of resistors as a voltage divider if the need be, (yes - I did say I was a software man, but I fiddled with some basic electronics 30 years ago). |
| Topic | Author | Date |
| AT89C55WD UART voltages. | 01/01/70 00:00 | |
| Level translation | 01/01/70 00:00 | |
| Thanks for that. | 01/01/70 00:00 | |
| Real? | 01/01/70 00:00 | |
| Real | 01/01/70 00:00 | |
| Reak! | 01/01/70 00:00 | |
| Voltage. | 01/01/70 00:00 | |
| Pins | 01/01/70 00:00 | |
| Pins | 01/01/70 00:00 | |
| the peculiar port structure of '51 | 01/01/70 00:00 | |
| The Socket | 01/01/70 00:00 | |
| Socket | 01/01/70 00:00 | |
| HW issues | 01/01/70 00:00 | |
| I am on the road, but someone can verify | 01/01/70 00:00 | |
| SN74LVC4245A | 01/01/70 00:00 | |
| 5V->3V conversion and vice versa | 01/01/70 00:00 | |
| If this is CMOS | 01/01/70 00:00 | |
| No insistance. | 01/01/70 00:00 | |
a link would be nice | 01/01/70 00:00 | |
| PLCC44 | 01/01/70 00:00 | |
| why AT89C55WD? | 01/01/70 00:00 | |
| Read the thread! | 01/01/70 00:00 | |
| AT89LV55? | 01/01/70 00:00 | |
| What is the blue tooth module? | 01/01/70 00:00 | |
| Module | 01/01/70 00:00 | |
| modules | 01/01/70 00:00 | |
| Modules | 01/01/70 00:00 |