16 Aug
2013
16 Aug
'13
6:38 p.m.
Hi List, When the SIMtrace ciruit operates in MitM mode, the RST and VCC lines coming from the phone are very noisy from I/O line crosstalk in the flex cable. I see about 2V peak-to-peak on the scope! I am expecting it leads to spurious reset/poweroff detections. It might be helpful to add a filter on the AT91 side for RST and VCC. Maye an R/C filter that can be enabled by an I/O pin using 0/HI-Z switching? Another idea is to do enable the internal AT91 pin pullups. Just loading RST and VCC a bit might be enough. ( Another alternative is to filter RST and VCC measurements in software. I tried this but results are not very meaningful at this point.. ) Cheers, Tom