RoadTest: PiFace Digital
Evaluation Type: Evaluation Boards
Did you receive all parts the manufacturer stated would be included in the package?: True
What other parts do you consider comparable to this product?: No one
What were the biggest problems encountered?:
First of all, sorry for my poor english!
Using the piFace for my project was incredible simple.
The board that element14 provided me for this road test is well engineered and simple to use.
But let me describe the project in detail.
The project is an home alarm based on a Raspberry Pi as server, a PiFace Digital as the connection with the sensors.
These one are 15 PIR sensors (each one for monitoring a room). To be considered that the PiFace has only 8 free inputs, so for my definitive project i'll need on other board to be stacked.
I've also used the relay output in order to activate:
So this are the project parts:
1 x Raspberry PI
1 x PiFace Digital
15 x PIR Sensors (LHI778 probe) as the free inputs are only 8
1 x Alarm siren
1 x High efficiency lamp
For the road test I've used only 4 PIR sensors and the leds on the PiFace digital because this is only a proof of concept for the complete project.
The PIR sensors
These sensors come from China and are based on the LHI778 chip:
Probe LHI778, high sensitivity.
The realization was incredible fast and funny.
The first step was to update Raspian Weezy software according to the instruction found here: http://www.farnell.com/datasheets/1684425.pdf
After this I'had to wire all the PIR sensors contact in order to enable the alarm.
The connection with the board was very easy because of the screw connectors.
In my case I had to wire the +5V on the output connectors and the GND on the inputs.
Coding the application is very simple.
Just a consideration about the sensor.
The PiFace input should be gorunded when the buttons are pressed, but the high level of the sensor output is 3.3V.
So I've to revert the logic inside the program.
The power of the PiFace is the coding: few rows of code and here is an alarm application!
# Alarm program by Francesco Balsamo
# Using a PIR sensor with inverted logic
from time import sleep
import piface.pfio as pfio
for pin_number in range(0,4):
if pfio.digital_read(pin_number) == 0:
pfio.digital_write(pin_number+4,1) # Using only the leds
pfio.digital_write(pin_number+4,0) # Disabling only the leds
Using the PiFace Digital for my project was very simple and funny since I needed only a screwdriver, some cabling and few rows of code.
Finally, I really like the board and how it is realized.
I think that this board is fantastic and it will be the core of many projects that I've in mind for automatize my house.