The Smart Water sensor board requires of both supply voltage lines from Waspmote (3.3 V and 5 V), which are activated and deactivated when calling the functions
Water.OFF() detailed in section "Library".
Solid state switches are used to cut the supply line of each sensor, all of which operate at 5V in the case of the Smart Water sensor board. Each switch is controlled through a digital pin of the microcontroller, so all of them can be handled independently of the others.
In the following table we can find detailed the consumption of the Smart Water sensor board and its different circuits in function of which of them is turned on. The total consumption of the mote would be the result of the sum of the consumption of the Waspmote in active mode plus the minimum constant consumption of the board plus the consumption of the circuits of the operating sensors at a given moment. All the information shown corresponds to the maximum current measured when the sensors are connected with the board and its circuit on. Remember it is possible to completely disconnect the Smart Water board, thus reducing its consumption to zero, using the library function
Minimum (constant, due to sensor board)
Dissolved oxygen sensor
Oxidation-reduction potential sensor
Minimum (constant, due to sensor board) 1.6mA Temperature sensor 3.5mA Conductivity sensor 2.5mA Dissolved oxygen sensor 160μA pH sensor 170μA Oxidation-reduction potential sensor 170μA Turbidity sensor 1.0 mA
The Smart Water sensor board has been designed to minimize the consumption of the mote during operation, allowing the activation of only the electronics that are really necessary to take the desired measurements.
Use the Waspmote low consumption modes
Like in the other sensor boards for Waspmote, the library of the Smart Water sensor board includes all the functions necessary to deactivate the sensors and the whole board so the mote can be put in low consumption mode to save battery when measurements are not being taken.