Sound-programmable e-paper badge with USB serial programming and 125 kHz RFID emulation

Sep 05, 2023

Project update 2 of 8

Wi-Fi Display Walkthrough

by Hristo Gerenski, Radoslav Gerganov, Georgi Gerganov

Greetings, everyone!

Now that the campaign has started, we’d like to start sharing some tips and tricks about GGtag. In this first update we will cover some basic usage of the web interface and programming the device.

Making a Wi-Fi tag

Let’s say we want to create a tag with Wi-Fi credentials for some hotel Wi-Fi network. The tag will show the Wi-Fi credentials in plain text and a Wi-Fi QR code. The Wi-Fi QR code allows people to connect easily to the network by scanning the QR code, without having to type the password.

For example, if the Wi-Fi SSID is "Hotel WiFi" and the password is "12345678", then the QR code must encode the following string:

WIFI:S:Hotel WiFi;T:WPA;P:12345678;;

Using the web interface

The next step is to put this together in the web interface. Since we have built-in support for QR codes, everything is pretty straightforward. You can find the final tag here, it contains two text elements, one icon and one QR code. The most important thing to remember when designing tags in the web interface is that you can move elements around by selecting them and then dragging on the canvas:

The command string of each drawing primitive (except RFID) starts with (X,Y) coordinates followed by some parameters. For example to draw the text SSID: Hotel WiFi at position (40,155) with font size 5, you need to add a text element with the string 40,155,5,SSID: Hotel WiFi.

You can find the exact command format of each drawing primitive by clicking the "Help" button.

Programming the device

Now when we have the tag ready, we can move to programming the device. If you want to program GGtag with sound, you need to place a CR2032 battery in the battery holder and flip the switch to "BATT" position. The green led on the back should light up and GGtag will start listening. Note that sound programming works only on battery power, i.e. you cannot program GGtag with sound when powered from USB.

To program GGtag over USB, you just need to connect it with to a USB host and flip the switch to "USB" position. There is no need for battery in this case. The red led on the back should light up and you are ready to go.

Should you have any questions, please feel free to reach out to us using the "Ask a technical question" link. Also if you come up with some cool tag designs, you are very welcome to share them with us in the GitHub discussions! And if you haven’t claimed your own GGtag yet, there’s still time while our campaign is live!

Until next time!

— GGtag team

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