Katherine is set up with a different set of temperature and humidity sensors to the other two sites (DHT11 compared to DHT22). The Raspberry Pi in the maser room also has an Arduino board attached to it for the accelerometer and some analog temperature sensors.

Connect the Raspberry Pi to the Arduino via a USB cable. The Arduino will get power via the cable but it's a good idea to also give the Arduino power via a DC power supply as this provides a more stable reference voltage for the analog sensors.

Each DHT11 sensor requires 3.3 - 5V, ground and a digital input pin. Pinouts are shown below: Use any 5V and GND pin from the RPi.

Any of the RPi digital pins should be fine to use. That’s the ones labeled BCM here: Raspberry Pi pinouts

These have three pins as well:

pin    connection
---    ---------------
-      GND
middle +5V
S      digital signal

Connect them to the Raspberry Pi. Any GND or +5V pin will be fine. Use any digital pin on the Pi and make sure they are set to “False” in TempHumid.conf (you can give them an appropriate label though). See below.

This should be connected to the Arduino:

module pin    Arduino connection
----------    ---------------
VCC           +5V
X out         A0
Y out         A1
Z out         A2
GND           GND

Attach the accelerometer to the maser (or whatever you want to measure). You might want to align it according to the orientation diagram on the module.

This should also be connected to the Arduino:

module pin    Arduino connection
----------    ---------------
T             A3
G             GND
H             A4
5V            +5V

These sites have a Raspberry Pi located in the antenna with DHT22 temperature and humidity sensors attached. They are also equipped with a 4-channel 12-bit analog to digital (ADC) board so that up to 4 analog signals could be monitored if needed. The DHT22 sensors are connected together on a bus that uses RJ45 connectors and CAT5 cables to daisy-chain up to 6 sensors from a single RJ45 connection.

The Raspberry Pis have an Adafruit Perma-Proto HAT to manage the wiring and to mount the ADC. Here's what it looks like (no RJ45 connector attached):

• Schematic of the connections (PDF). Links to details on the hardware:
  • Adafruit Perma-Proto HAT
  • DHT22 temp/humid sensor datasheet
  • ADS1015 12-Bit ADC - 4 Channel with Programmable Gain Amplifier

The DHT22 has 4 pins but pin 3 is not used.

Each one requires a connection to power and ground plus a unique GPIO port on the Raspberry Pi for data. The RJ45/CAT5 has 8 wires. Two are reserved for power and earth so that leaves 6 for sensors. The RJ45 terminal blocks have a different wire colouring to the CAT5 cable. Here's how they are allocated: