How to make a time marking machine with Raspeberry and Nios4 (first part)
Let’s make the circuit of an attendance marking machine with Raspberry
You can also realize an outdoor attendance marking machine by using a waterproof box and including a battery. This way, it will be either independent and placeable anywhere.
In the cover photo, you can see the one that we realized for the office: the device is fixed to the wall and powered directly.
Connect the RFID reader and the LCD headset to the Raspberry, as you can see in the diagram below.
In the example with the battery, I used a TP4056 to charge the battery and leave the Raspberry Micro-USB ports free.
Inside the Models folder, you will find the 3D printing projects for the structure that you will put inside a Gewis GW44426 watertight box. This structure has a bracket for the Raspberry Pi 3 and one for the Raspberry Pi Zero.
There is also another project to create a complete case for the Raspberry Pi Zero.
Of course, the possible box and the arrangement of the various elements are completely at your discretion.
Installation of the basic software
To use your Raspberry Pi, you need a Micro-SD card.
Follow these steps to install the operating system:
Install the full version of Raspbian. Then, insert the SD card in the Raspberry Pi.
To connect the Raspberry, you need:
Monitor connected with an HDMI cable
Mouse and keyboard
After restarting the device, select Menu → Preferences → Raspberry Pi Configuration, then select the Interfaces tab and enable: SSH, SPI, and I2C.
You can also install VNC or use SSH directly to connect remotely.
Verify that the hardware works
Then, write the following command on the console:
lsmod | grep spi
The address grid is displayed. If there is a number inside the cell, it means that the LCD viewscreen is properly connected.
Install the SQLite libraries
Normally, the libraries should be already installed on Raspberry, except for those related to database management.
In this example, I use the SQLite database. If you prefer another data source, you need to change the sources.
As a good practice, update the Raspberry by giving the following commands:
sudo apt-get update
sudo apt-get upgrade
After the update, it is time to install the SQLite libraries:
sudo apt-get install sqlite3
After doing it, you are ready for the next article in which you will upload programs in Python to read data from the RFID and send it to a Nios4 cloud database.