I'm building a simple RS232 data logger with the Sparkfun OpenLog and a SEEED RS232-TTL adaptor. I'm powering it with a 9 volt battery and a 7805 voltage regulator.
It's dead simple. I built it on a breadboard first and determined that TX-TX and RX-RX connections are called for. I logged several files on the breadboard then soldered it all up. Now it's not working, sigh.
When I power it up both lights will flash rapidly for about a second and then it settles down to a steady on-off with both lights.
If I delete the config file a new one is created, which shows that it recognizes the card at least.
I've triple checked my wiring and confirmed I have no shorts, and that the voltage is good.
I'm attaching a photo as built. Hopefully it's obvious what's what. The purple trace is ground.