The GMC-320s are new units from GQ Electronic and may have some problems with their large memory.
So please follow these manual steps to clear the memory and reset the GMC-320 unit.

1. Push #4 button - once - Unit goes into menu mode
2. Push #3 button - twice - Save Data
3. Push #4 button - once - Save Data menu
4. Push #3 button - 3 times - Erase Saved Data
5. Push #4 button - once - Yes, then let it go back to Save Data menu
6 - NO, push #4 again - Yes and let it go back to Save Data menu
7. Push #1 button - once - Main menu
8. Push #4 button - once - User Options menu
9. Push #3 botton - 4 times - Reset Total Count
10.Push #4 button - twice - Yes, then let it go back to User Options menu
11.Push #1 button - twice - Exits Menu mode

Turn off the GMC-320 power by pressing #4 button
Plug GMC-320 back into the PI and then turn on GMC-320 power.

This procedure should clear the spike.

Harlan

PS if you want the spike removed, email me with site id and data and time. I believe false spikes should be removed, but it is your choice. harlan