cshea@updesigns.comHi Leon,
First, thank you for the help. Your first response led me in the right direction. As I mentioned, I had the reset line connected to my Nucleo board. The line was configured as a general purpose output and was not being properly initialized to the logic level high. I didn’t realize that as an issue until you pointed out that there is an intermediate micro (ATtiny9) handling reset and power based on the reset signal on the interface header. When I read the section of the document that you pointed me to, I realized that I initiating a power down of the Ublox radio when holding the reset line for longer than 1 second. I updated my application to properly control the reset line and all is working properly. I apologize for the user error.
Thanks again!
Casey
cshea@updesigns.comThank you for the quick response. To clarify, I am not trying to control RADIO_ONOFF or RADIO_RESET. I was just monitoring them with a scope to see if they could indicate for me why the U-blox radio is not responding.
I was able to locate the ATtiny9 and verify the path between the reset line on the connector and ATtiny9. Not that I doubted it but was more interested than anything else.
Most importantly, I am still having the issue in which the modem only stays on for 20 seconds. Any thoughts on why this may be occurring? Power is good, there are no glitches on the reset line, a command is not being sent to power off the unit, and the unit does not have Power Saving Mode enabled. In fact, even if I just reset the unit and don’t issue any commands at all, the same behavior is observed.
