I have previously asked about a buoy where the GPS stopped working after several months. But which we do not yet have access to. Recently, we had another buoy stop working (transmitting), and I managed to get hold of it before it went into the water. Our MCU keeps restarting (indicating that it does not get contact with the notecard), I’ve checked that the voltage is good (output from the lithium-capacitor regulator you sell). There is a vague orange/red light constantly on on the notecard. It’s got an external SIM. The device has been without coverage for prolonged periods of time, so it has probably tried to connect a lot. It might also be full of log messages from the MCU which, but my understanding is that it will protect itself from getting to full.
It’s running the 6.1.1 firmware.
In these cases it would be very useful to send a command to the notecard to restart it. Though in the latter case it doesn’t even connect.
There was no response when connecting through microUSB, the device did not show up. When pulling EN low the light just dimmed slightly, and went back up to its semi-dimmed state. I attached a debugger to the MCU and it gets no response over I2C. The power was fine, there was 3V3 on VIO, there was 3.8V on VIN. Swapped out the entire board (carrier, notecard, MCU), and connected to the same regulator and it works.
I hooked the device up using microUSB back in the lab. I don’t get a ttyACM0 device, but the kernel log shows the device to be recognized as a STM32 bootloader:
$ journalctl -k -r
Apr 15 09:43:14 pc5857 kernel: usb 3-1.3: Manufacturer: STMicroelectronics
Apr 15 09:43:14 pc5857 kernel: usb 3-1.3: Product: STM32 BOOTLOADER
Apr 15 09:43:14 pc5857 kernel: usb 3-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Apr 15 09:43:14 pc5857 kernel: usb 3-1.3: New USB device found, idVendor=0483, idProduct=df11, bcdDevice=22.00
Apr 15 09:43:14 pc5857 kernel: usb 3-1.3: new full-speed USB device number 26 using xhci_hcd
Apr 15 09:42:56 pc5857 kernel: usb 3-6.3: USB disconnect, device number 13
Apr 15 09:41:55 pc5857 kernel: usb 3-6.4.2.3.1: reset high-speed USB device number 20 using xhci_hcd
Apr 15 09:40:54 pc5857 kernel: usb 3-6.4.2.3.1: reset high-speed USB device number 20 using xhci_hcd
