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RX/TX died

Posted: Wed Feb 15, 2012 1:57 pm
by rubergd
Hi! I have been using an older SB70 paired with a Stamp BS2 for a fixed e-mail application that has been running perfectly for over a year. Out of the blue, the Pink RX and TX ports stopped functioning. Did the usual, rebooted, verified baud rate (2400, N,8,1) with IPSETUP and the Config web page, swapped BS2 modules and reloaded program. Even re-loaded PINK firmware 1.36. Power supplies are fine (Pink has its own 5.0V/2A.). BS2 and PINK share common VSS. Can read and write variables through the Pink factory web interface just fine. Tried the Parallax Stamp test programs for reading and writing variables. SEROUT had no effect on variables, SERIN gave timeout. I ran a Telnet monitor session, which connected, but no serial activity was displayed when the read/write variable programs were run. When trying to write variables, I put a sccope on BS2 SEROUT pin and saw outgoing pulse train to PINK RX pin as expected. When trying to read variables, the scope showed nothing coming back from PINK TX pin to BS2 SERIN pin. (Not surprising, if the problem was that PINK didn't receive the Read command in the first place!) I'm wondering if the the Pink Serial I/O circuit has bit the dust and if there is any way to determine this. Any ideas? Thanks in advance!