| ??? 07/16/08 23:06 Read: times |
#156782 - SAME modem? Responding to: ???'s previous message |
Craig Steiner said:
as far as we can tell the EXACT same circuit on the modem's evaluation board WILL turn it on AND off (as it should). Are you using the SAME modem in both boards (eval and customer's)? Different modems can have different firmware and/or setup... Craig Steiner said:
2) The microcontroller is controlling the DTR line going to the modem. It starts out at 0V (correct) and I raise that line and I measure the line at 2.7V (rather than 3V)[...] I think these two issues might be related. Setup again? Line definition changed to output by setup/different firmware? (A series resistance would reveal fighting outputs, btw.) Try to eliminate the unknowns. Start out of the known (the evalboard) and change as little as possible. I know this is preaching of little help, but maybe some sort of starting over might help a bit... JW |
| Topic | Author | Date |
| Strange "digital" voltages | 01/01/70 00:00 | |
| still have hair left??? | 01/01/70 00:00 | |
| Are you looking at backdriving? | 01/01/70 00:00 | |
| Driver chip | 01/01/70 00:00 | |
| Sometimes, the solution is easy... | 01/01/70 00:00 | |
| Have you washed the board? | 01/01/70 00:00 | |
| SAME modem? | 01/01/70 00:00 | |
| Sounds to me like your trying to drive an output. | 01/01/70 00:00 | |
| DTR current | 01/01/70 00:00 | |
| Quiet in here ? | 01/01/70 00:00 | |
He's busy fixing it! | 01/01/70 00:00 |