V2 smart controllers support different sensors including digital sensors(eg a float switch), analogue sensors(eg photocell), 1-wire sensor(temperature), i2c, serial and usb based sensors The v2 board can interface most of these directly without any extra external circuitry.
connecting digital sensors to v2 controllers using internal software based pull-up resistors is easy because digital sensors mostly have two connections, or three if they are active and require a power source. One contact connects to the respective digital pin eg D4 on the board and the other contact is grounded. the arduino style syntax for activating the internal pullup resistor is:
: pinMode(4,INPUT_PULLUP); where 4 indicates that the internal pullup resistor on digital pin D4 is activated
a schematic for this is shown below:
connecting analogue sensors to a v2 controller is easy as well as they mostly have two pins or three if they are active sensors types. One of the analogue sensor is connected to the analogue pin such as A6 and the other to ground. internal pullup resistors can be activated on the atmega chip as well. but they are not accurate for critical analogue sensor measurements. so ten analogue input pins A10-A9 have an onboard switchable pullup 10k resistor through the dip switch on the v2 board. These are activated through the respective on-board dip switch. a schematic for this is show below:
Connecting 1-wire digital sensors to a v2 controllers is also very easy as well. 6 pins D26, 27, 28, 29, 30, 31 have a switchable 4.7k parasitic resistor connected. These are connected to the respective dip switch. pin D26 is preconfigured for 1-wire dallas temperature sensors, whereas D27 for the typical arduino humidity/temp sensor. A typical schematic is shown below;
The following panel connectors will work on the eco v2 enclosure. for sensor connections sensors are connected on to the enclosure using 3.5mm audio connections. The panel socket connectors are shown below: