Raspberry Pi Zero W - Setup And Read Your First Sensor

Install Raspian OS

Raspbian is the Foundation’s official supported operating system. You can download it in the following link: https://www.raspberrypi.org/downloads/raspbian/

After downloading the image you need to download win32disk imager software to write the system image to a SD card. https://sourceforge.net/projects/win32diskimager/

The next step is to insert your SD Card in the Raspberry Pi slot.

*If you dont have a screen to configure your board, i recommend to enable UART in config.txt file located in your SD card. Insert this line at the bottom of the archive.

Let's enable I2C communication too:

#Enable UART 
enable_uart=1 
#I2C 
dtparam=i2c1=on 
dtparam=i2c_arm=on 

Connect a FTDI module to UART pins and open Putty with baud rate of 115200bps.

To enable ssh create a ssh file in the SD card.

Raspberry will boot and now you are able to start!

Configure Wifi

To configure wifi you need to edit wpa_supplicant.conf file. Once connected to Raspberry serial via Putty, type the following command:

pi@raspberrypi:~ $ sudo nano /etc/wpa_supplicant/wpa_supplicant.conf

Insert this at the bottom.

network={ 
   ssid="testing" 
   psk="testingPassword" 
} 

Reboot your system and verifiy wi-fi connection.

pi@raspberrypi:~ $ sudo iwlist wlan0 scan 
pi@raspberrypi:~ $ ifconfig wlan0 

Using TCS34725

• Install I2C tools:

pi@raspberrypi:~ $ sudo apt-get install -y i2c-tools  

• Detect I2C sensor:

pi@raspberrypi:~ $ i2cdetect -y 1 

I2C detect will show you all the devices connected to Raspberry I2C bus. In this case TCS34725 address is 0x29.

• Dumpy registers visible through the I2C bus.

Code

First of all, create a folder and install wiringPi library.

pi@raspberrypi:~ $ mkdir code
pi@raspberrypi:~ $ cd code
pi@raspberrypi:~/code $ git clone 
pi@raspberrypi:~/code $ cd wiringPi
pi@raspberrypi:~/code/wiringPi $ ./build

Download the code:

https://github.com/leoribg/codes_general , the code is located in i2c folder.

Copy it to code folder and compile.

pi@raspberrypi:~/code $ g++ i2c_code.cpp -lwiringPi -o i2ctest
pi@raspberrypi:~/code $ ./i2ctest
fd =3 
data=1 
R=277   G=279   B=282 
R=277   G=279   B=282 
R=278   G=279   B=283 
R=278   G=279   B=283 
.
.
.
R=277   G=279   B=282 
R=277   G=279   B=282 
R=278   G=279   B=283 
R=278   G=279   B=283 

The code will run indefinitely printing RGB values by 2 and 2 seconds.