Hello - I have only programmed Arduinos for inputs and outputs such at reading PH and Temp and deciding to dose acid in a pool. I have not collected data other than when I was trouble shooting and dumping to a PC. I now have something I would like to try for work. I would like to read the levels of tanks holding liquids that are remote in the field. With any luck this could end up being a large number. I would like to collect data only once per day. The connection of the Arduino to a network would be either a cellular network or a customers WIFI network. I would be happy to collect the data into a flat file, excel file or Access file or other options if you suggest them and it doesn't cost too much. What I can't wrap my head around is how does each Arduino access the same file and not have the possibility to have more than one unit trying to access it at a time. I would think maybe a better solution would be to have a PC or a server at work call the Arduinos? Or maybe each Arduino has its own file that is appended to a master file later?
Any thoughts would be appreciated along with any wifi and cellular hardware suggestions.
Anthony