My nRF9160 Thing Plus will not enter boot mode, and the yellow/orange LED is solid ON. I have searched the docs and cannot find what the solid on LED means. I believe the at_client example is loaded onto the board. Does anyone know what this means and/or how to get the thing into boot mode? Thanks!
Check out the “Buttons” section here https://learn.sparkfun.com/tutorials/nr … e-overview that explains how to get it goin’
Thank you. Let me explain a little more fully. I have been able to get the device into boot mode and flash code, but it will not always enter boot mode when I try with the buttons. I asked about the LED, which I believe is simply the power LED, because it’s behavior is odd (sometimes on, sometimes off, occasional intermittent blinking) and I could find no solid verification that was the case. I was recently able to update the modem firmware, but have not yet been able to confirm the update worked due to my issue. However, I have noticed a pattern.
After not powering the device for some time, around at least an hour, I am able to plug in the device and put it into boot mode the standard way with the buttons. However, after the first minute or so of the device being powered, it will no long enter boot mode until I unplug it for at least and hour. Simply unplugging it for a minute or two does not work. The only behavior I observe is that the yellow/orange LED is always on when it is plugged in, but does not immediately turn on after the device has been sitting for that long time.
I thought perhaps the solid yellow LED was trying to tell me something about the state of the device, as I know the nrf9160 has some sophisticated power management and low power modes. I have not reviewed the circuits beyond the schematic level, but I wonder if the device is going into some kind of sleep mode after it runs whatever example script I have loaded. I cannot wake it up again (not even using the reset button), and i wonder if there is perhaps enough energy stored in components in the circuit (like a smoothing capacitor in the power handling) to keep it powered in the low power state (potentially only drawing 2uA) for some time, only exhausting it’s power after approximately an hour. The behavior is consistent, but I don’t have small enough probes for my multimeter to go poking around to see if there’s power coming from somewhere.
One last detail. My computer knows the device is connected and I can open a serial line to it. I have not attempted any commands over serial as I don’t yet know them or if they’d even work since the device isn’t in boot mode or running any code that allows back and forth communication.
I think I’m going to get a programmer for the device and see if that greater control and access helps me out. This is an odd issue.