Good day, everybody.
I've recently purchased VEMS 3.7.
My problem is that VemsTune (VT ver 2011-07-20) does not see the device. All grounds are joined, power is 12.2 V.
I tried direct connection to RS232 port (through max232 on board) and USB<->RS232_TTL converter directly to the header near the MCU.
Both cables I used worked fine with MSAVR 2.2.
Then I've discovered that TX pin of the AVR is at 3.1v, but MSAVR 2.2 has 5v on it.
Resetting manually by shortening Res with Gnd lines in the header did not change state of the TX line.
PonyProg detects MCU device properly, but it shows all BL fuses are programmed, along with Lock1, Lock2, M103C, WDTON,
BODLEVEL, BODEN, SUT0, SKOPT, EESAVE, BOOTSZ0, BOOTRST. Datasheet says SUT1 should be programmed when BOD is enabled.
But, I dont know exactly if these settings mean anything if Lock1 & Lock2 are set, since they disable ISP-mode prog.
Max232 is alive (loopback ok). Atmega seem to stay in reset. Oscill shows no movement on TX line and others after reset.
The voltage on res pin is 4.4v. AREF pin is 0v. AVCC is 5v, power is good. Oscillator is running.
What should I do next?
------
The problem was in ATMega MCU. It was replaced.