SD Card reading and writing test.
This string may be modified as needed, by adding (or not) other values or separators. The writing on the SD Card follows as well as the idle cycle, waiting for a new acquisition. The time interval between the acquisitions may be set by means of the timeToLog variable, that is set to 60,000 ms (1 minute) by default. We considered that the module remains turned on only for the short time needed in order to connect to the network and to receive the data from the NTP server; for the rest of the time between a log and the following one, the module is brought to a power-down status, thanks to the D7 pin’s signal that commands the EPS8266 integrated circuit’s CH_PD pin.
This allows for considerable energy savings, even though continuous connections to the WiFi network are needed.
In the SD Card you will find a file named DATALOG.TXT and containing all the acquired values, as shown in figure. This sketch is compatible with modules in which the 9.02 and 9.03 firmware versions (such as the one installed on our shield) have been installed.
Report concerning the sketch.
Content of the sketch’s log file.
