The Voice It includes an RFID reader board that reads “user data” from a “near field” RFID tag once it’s brought in close proximity (about 15 mm). Specifically, the Voice It reads tags that have been encoded with data according to the Mifare standard. Several kinds of tags work well with the Voice It:
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| sticky tags | RFID fobs | rigid tags | rigid cards |
These tags are inexpensive, normally costing about 30 cents per tag. Like anything else, they’re even less expensive when purchased in bulk. We recommend the sticky tags for use in our Bliss Tactile Symbols and RFID fobs for language changes with the Voice It.
Tag Data
There are two types of data that you can put on the RFID tag.
The first is the name of the WAV file that you’d like the Voice It to play. For example, if you put the text, “hello”, on the RFID tag, the Voice It will look for a file on the SD card called “hello.wav” and attempt to play it. You can tell the Voice It to play several files by stringing together several filenames, separated with a comma. For example, if you put the text, “hello, goodbye” on the RFID tag the Voice It will first look for and attempt to play the file “hello.wav” and then look for and attempt to play the file “goodbye.wav” one-half second later. You can string together as many filenames as necessary – up to a maximum of 37 characters.
The second, is an instruction to the Voice It that it should start speaking in an alternative language. By default, and after a restart, the Voice It looks for files in the English (en) folder on the SD card. You can tell the Voice It to start looking in an alternative folder for files by using a special RFID card containing the the text “*xx”. As a convention, you replace the two x’s with the two-character standard code for the language.
The Voice It WAV files have two folders: “en” and “es”. The “en” folder contains English recordings for 259 words associated with the Bliss Tactile Symbols core vocabulary. The “es” folder contains recordings in Spanish for the same 259 words. Fob-style RFID tags work well for creating these “language change” tags. To create a tag that changes the Voice It language to Spanish, put the text, “*es” on the tag. To then get the Voice It to speak English again you can either prepare a tag with the text, “*en”, or you can simply reset the Voice It using the reset button.
Note that, in the WAV files folder, there are three files that sit outside of the “en” and “es” sub-folders. They are called: “error.wav”, “set volume.wav”, and “startup.wav”. “startup.wav” is played automatically when the Voice It successfully starts up. “error.wav” is played whenever the Voice It is instructed to play a file (by reading an RFID tag) but it can’t find a file with that name followed by “.wav”.
“set volume.wav” is a special recording that is about a minute in length. That should give you enough time to set the volume level of the Voice It by inserting a screwdriver into the volume control channel on the side of the box. You will need to create an RFID tag with the text “set volume” encoded on it. This is another perfect use for a fob-style RFID tag.
Writing Data to an RFID Tag
To write text to an RFID tag, you’ll need an RFID tag reader/writer. We’ve had success with this device. Set aside any software that comes with the device. You only need to plug it into your PC. It’s a plug-and-play device.
You’ll also need software to control the device. The NFC Tools for Desktop software from Wak Dev is free and very easy to use. The images shown below are taken from that software. Note: Your RFID tag reader/writer hardware may come with software. Set that software aside for now. The program from Wak Dev will probably be sufficient.
Connect the RFID tag reader/writer to your computer using the USB interface and start-up the NFC Tools software. You’ll see a window like this:
Place a new RFID tag on the surface of the reader/writer. Note that the reader/writer has a significant read/write distance, so it will easily read from and write to a tag which is already embedded in another object – like a Bliss Tactile Symbol or a fob-style RFID tag.
The reader/writer will read the tag and the screen will change to look like this:
Note the entry under the “TECH: ISO 14443-3A” heading. It says “NXP Mifare Classic 1k”.
The Voice It can only read RFID tags that adhere to the Mifare standard. If you put a rigid tag on the reader/writer you’ll see “NXP Mifare Ultralight”. This tag adheres to the Mifare standard, and so can be read by the Voice It.
Click on the “Write” tab and the window will change to look like this:
Click on the “Add a record” button and choose “text” from the pop-up list:
A smaller window will appear:
Type your text into the “Enter your text:” box. Don’t press the Enter key to close the box.
Instead, click on the “OK” button. You’ll now see the screen change to show the text record option you’ve created. The text hasn’t yet been written to the RFID tag.
Note that you can have the Voice It speak multiple words by putting the text of those words on the RFID tag – separated by commas (e.g., “not, don’t”). The amount of text that you can put on a single tag will vary with the type of tag. In the above example, the Voice It will first say “not” and then, one-half second later, it will say “don’t”. If the text you put on the tag doesn’t match the name of the audio recording – or if the text you type is truncated because there’s not enough memory on the tag – you’ll hear the error sound (a “thunk” sound).
Now click on the “Write” button and the reader/writer will write that text to the RFID tag:
You can verify that the tag has been successfully written by clicking on the “Information” tab:
Of course, the best way to verify that the tag has been written correctly is to set the tag on the Voice It and listen for the correct recording to play. If you’ve miss-typed the word, you will either hear the wrong recording play or you’ll hear the “error” sound – meaning that the Voice It couldn’t find a file with that name.
Writing Many Tags in Sequence
If you’ve just printed 10 Bliss Tactile Symbols, each with an embedded blank RFID tag, you won’t want to follow this process exactly for each tag. You can write the tags much more quickly by:
- Set first symbol on the reader/writer.
- Click on the Write tab and create a text option with the appropriate text.
- Click on the Write button and dismiss the “successful write” box.
- Remove the symbol and set it on the Voice It to verify the tag.
- Set the next symbol on the reader/writer.
- Select the “pencil” icon to the write of the text option.
- Edit the text to the appropriate value for the next symbol.
- Click on the Write button and dismiss the “successful write” box.
- Remove the symbol and set it on the Voice It to verify the tag.
- and, repeat for the remaining symbols…
Correcting an Error
If you make a mistake in writing a value to the tag or if you’d just like to remove all the content you’ve written to the tag:
- Set the tag on the reader/writer.
- Click on the “Other” tab.
- Click on the “Erase (empty record)” button.
3D-Printing a Bliss Tactile Symbol and Embedding an RFID Tag
The following video shows how a tactile symbol is sliced and printed – including insertion of an RFID tag and changing filament colors to make the Bliss graphic stand out for visually impaired individuals: