Chirp! Moisture Sensor to Arduino Uno - Physical Connection Questions

Projects General Guidance
1

I'm completely new to Arduino, and electronics really, so please bare with me.

I have looked up some info on how to connect the Chirp! Moisture Sensor to the Arduino Uno. I've found some conflicting info on how to connect them, so I just wanted to make sure I was doing it correctly and don't screw anything up.

Here is a link to the sensor: http://wemakethings.net/chirp/

In this link they mention this connection:

pin 1 - MISO
pin 2 - VCC
pin 3 - SCK / SCL – I2C clock
pin 4 - MOSI / SDA – I2C data
pin 5 - RESET
pin 6 - GND

However, they did offer some Arduino Code and mentioned this connection:

Chirp pin 1 - no connection
Chirp pin 2 - Arduino VCC
Chirp pin 3 - Arduino A5
Chirp pin 4 - Arduino A4
Chirp pin 5 - Arduino pin 2
Chirp pin 6 - Arduino GND

My confusion comes from the fact that the Arduino has a MISO connection, but in their Arduino code they aren't using it. Same with other connections.

Which one is correct?

Secondly, I want to verify the power. My understanding is that the USB connection on the Arduino is 5V. Is this enough/correct for the Chirp! sensor? And if I connect through the Arduino I'm assuming I don't need a battery for the Chirp! sensor.

Thanks in advance for your help. I really appreciate any help you can provide.

Dave.

2

dksmc:
My confusion comes from the fact that the Arduino has a MISO connection, but in their Arduino code they aren't using it. Same with other connections.

The 6-pin connector is dual-purpose.

It can be used to connect the device as an i2c slave to another Arduino. For this purpose, use the connections as shown in the example code.

It can also be used to re-program the chip on the sensor. This is when the other connections: MISO etc. would be used. As you are not doing that, no need to worry about those other pins.

Paul

3

Thanks PaulRB. That was very easy to understand and helpful!

Dave.