Thanks all for the feedback.
The rpi3 is installed in the van. You could look at my profile for details.
While here at home, the rpi3 is connected to the home wifi. When traveling, it will be connected to a mifi in the van.
The rpi3 will be headless. Right now I have a wireless USB keyboard and an HDMI to monitor cable attached until I can automate reconnection to the mifi(LAN) during reboot.
The rpi3 uses between 0.28A to 0.34A per the DROK USB power meter. That translates to ~8Ah/day.
I have booted the rpi3 with a 1A rated USB charger. It took several tries before I found a good enough USB cable to carry the power. Get good cables! I run it in the van with a 2.4A Anker 12V car-plug charger.
I want to keep the power low, so no external drive.
For backup, I copy the data and programs from the rpi3 with my laptop's file manager which connects to the rpi3 via ssh.
If write-wear on the micro-sd card becomes an issue, I could reduce sqlite3 writes to once per day by keeping an intraday database in memory.
A cron is run each minute to capture the data.
The programming language is PHP5. Installing PHP automatically includes the apache2 web server. PHP facilitates dynamic html.
I could under-clock if I have thermal issues!
Per 'top', my PHP code uses between 2% and 4% CPU while extracting from the controller and saving into the sqlite3 database.
I have had too much pi today!
Can I interest anyone with analysis of the log data? After all, the goal of the project is to understand what happens.
HTH;
John
