AkidaTag user guide

This guide is for someone who has an AkidaTag with BrainChip’s firmware already on it and wants to run the demos from a phone. It covers installing the BrainChip Connect app, connecting to the tag, what the LEDs mean, running the keyword spotting demo, updating the firmware, loading a model, and what to do when something does not work.

It was written from the source code of the firmware on the main branch of the AkidaTag repository and of BrainChip Connect on its main branch.

If you want to build the firmware or write your own application, read the developer guide instead.

1. Before you start

You need:

• An AkidaTag.
• A USB-C cable, for charging. None is included.
• An Android phone running Android 13 or later, with Bluetooth. The app is coming soon to the iOS App Store.
• The BrainChip Connect app. Its Google Play listing, https://play.google.com/store/apps/details?id=com.brainchip.connect, is open for pre-registration.

In the box is the AkidaTag board in its enclosure, with the latest firmware release and the keyword spotting model already loaded. No battery, camera or USB-C cable is included.

Charging

The USB-C connector charges the tag. While the app is connected, the applications screen shows the battery level and, next to it, Charging while the tag is on charge, Warning for a charging fault the tag can recover from, such as over-temperature or a timeout, and Fault for one it cannot, such as an over-voltage.

The datasheet has the battery and charging figures.

Turning the tag on and off

Use the power switch to turn the tag on and off. The board also has a user button and a DFU button. In this firmware release the user button does nothing; a reset function for it is planned. The DFU button is not needed for anything in this guide.

2. What the LEDs mean

The tag has a green LED and a red LED.

What you see	What it means
Green blinks slowly, red off	The tag is running and waiting for a phone to connect.
Green on, red off	The app is connected.
Red flashes for about half a second	The tag detected a keyword.
Red on, green as before	The tag is in an edge-learning session, listening for a word to learn.
Green on, red blinks quickly	A model is being received from the app.
Green on, red on	The model is being written to the tag’s flash memory.
Both LEDs blink three times together	The model was stored.
Green off, red on steady	A model transfer failed, or the tag is in its update mode over USB. See Troubleshooting.

3. Install BrainChip Connect

1. Pre-register for BrainChip Connect on Google Play at https://play.google.com/store/apps/details?id=com.brainchip.connect. Google Play tells you when the app is released. It is coming soon to the iOS App Store.
2. Open it. The first screens introduce the app and ask you to accept its terms and its privacy policy.
3. Grant the permissions it asks for. Bluetooth is required to find and connect to the tag. Notifications are optional and are used for alerts about model events, firmware updates and device status.

4. Connect to your AkidaTag

1. Make sure the tag is on: the green LED blinks slowly.
2. In the app, open the device list. The app scans for boards that carry a BrainChip Akida processor and shows the tag as AkidaTag. If the list stays empty, see Troubleshooting.
3. Tap the tag. A preview screen shows its name and signal strength.
4. Tap Connect to Device. The app shows two steps, Establishing connection and Syncing configuration, and then opens the Select the Application screen. The green LED stays on while the app is connected.

The tag does not ask the phone for a pairing code, so no pairing request appears.

Only one phone can be connected to a tag at a time. If the app cannot connect, check that another phone is not already connected.

5. Run the keyword spotting demo

The tag ships with one demo, Keyword Spotting. It listens through the microphone on the tag and recognises ten spoken words: down, go, left, no, off, on, right, stop, up and yes. Everything else is reported as silence or unknown and is not shown.

The tag arrives with the keyword spotting model already loaded, so the demo is ready to run. If the tag has lost its model, load one first: see Load a model.

1. On the Select the Application screen, find the Keyword Spotting card. More Information shows the model name, its input shape, the number of classes and the list of keywords.
2. Tap Run Application. The badge on the card changes to Starting and then Active once the tag has confirmed it is listening.
3. Say one of the keywords. The microphone on the tag is a quiet part, so speak clearly and close to it. Each detection appears in the banner on the card with its confidence, and the red LED flashes for about half a second.
4. Tap Stop Application when you are finished. The tag stops listening.

6. Update the firmware over Bluetooth

New firmware is published on the releases page of the AkidaTag repository: https://github.com/Brainchip-Inc/AkidaTag/releases. Each release attaches a file for updating over Bluetooth, akidatag-<version>.signed.bin, and a package akidatag-<version>-dfu.zip that holds the same image. The app accepts either. The SHA256SUMS.txt file lists the checksum of every file, if you want to verify a download.

Keep the tag on the latest release, https://github.com/Brainchip-Inc/AkidaTag/releases/latest: the app loads models with a transfer that older firmware does not have, so update the firmware before loading a model.

1. Download the firmware file to your phone.
2. Connect to the tag and open Settings from the bar at the bottom.
3. Tap Firmware Update, then Browse Local Firmware, and pick the file. The app reads the version out of the file and shows it. If the file is signed with a different key from the last firmware the app installed on this tag, it warns This file may not install; a tag from BrainChip accepts only BrainChip’s release firmware.
4. Tap Install This Build. Keep the app open and stay near the tag.
5. The app sends the firmware, asks the tag to restart, and then waits for it to come back. The wait can take up to two minutes. Do not power the tag off.
6. The app reports what the tag did:

The app says	What it means
Update installed	The tag is running the new firmware, confirmed after it restarted.
Update did not install	The tag refused the firmware and restarted on its previous version. It never says why. The usual cause is a file signed with a different key.
Your AkidaTag did not restart	The firmware was sent but the tag did not restart. It may install the next time the tag is powered off and on.
Update failed	The transfer did not complete. The tag is still running its previous firmware.
Could not confirm the update	The firmware was sent but the app could not find the tag again afterwards, or the tag would not say which version it runs. Reconnect to the tag to see its version.

Current Build on the Firmware Update screen shows No Build Installed until you have installed a firmware through the app. That does not mean the tag has no firmware.

A firmware update leaves the model on the tag in place.

You can also update the tag over its USB-C cable from a computer, with no phone. That path is described in the developer guide under Firmware update over USB-C.

7. Load a model

Every firmware release attaches two model packages: akidatag-kws-model.zip, the keyword spotting model the tag ships with, and akidatag-kws-edge-learning-model.zip, the same model with room to learn new words on the device. Each holds three files, info.yaml, kws_program_info.bin and kws_program_data.bin. Do not unzip it.

1. Download the package to your phone.
2. Connect to the tag and open Settings, then Model Update.
3. Tap Browse Local Model and pick the .zip file.
4. Tap Install Model. The app sends the model in blocks and the tag writes each block to its flash memory as it arrives: the green LED stays on and the red LED blinks quickly, then both are on while a block is written. You can tap Stop Update during the transfer; the tag is then left without a model until a transfer completes.
5. When the whole model is across, the app shows Installing on your AkidaTag. The tag checks the file, programs it into the Akida processor and runs a test inference, which takes a few seconds. Both LEDs blink three times together when the model is stored.
6. The app reports the result:

The app says	What it means
Model installed	The tag has the model and is running it.
Model delivered, but not running	The model was stored but the tag could not start it. Restart the tag, which makes it try again. If that does not help, this model is not one this tag can run.
Model update failed	The transfer did not complete. If the tag was replacing its model, it has no model until one is sent in full.

The tag holds one model at a time. Loading a new one replaces it. The model stays on the tag across restarts and firmware updates.

Current Version on the Model Update screen shows Not Found until you have installed a model through the app.

8. Other things the app shows

• The i button in the header opens Device Information: the tag’s name and hardware details.
• Notifications lists the events the app has received from the tag.
• Settings > Factory Reset restarts the tag. A full factory reset, one that erases the model and your settings, is not in this firmware yet and will come in a later release. Today the app disconnects and the tag comes back advertising on its own, with everything still in place.
• Settings > Power Mode is where a low-power mode will be switched on to save battery. In this release it changes nothing on the tag; the feature will come in a later release.

9. Troubleshooting

Problem	What to check
The app does not find the tag.	Bluetooth is on and the app has its Bluetooth permission. The tag’s green LED is blinking; if it is solid green, another phone is connected. If no LED is lit, charge the tag.
Connection timed out.	Move closer to the tag and try again. Restart the tag if it keeps happening.
No keywords are detected.	The application is Active on the card. Speak clearly and close to the tag; its microphone is a quiet part.
Update did not install.	The firmware is signed with a key this tag does not accept. Use a release from https://github.com/Brainchip-Inc/AkidaTag/releases.
Model delivered, but not running.	Restart the tag. If it still does not run, the package is not for this tag.
Model update failed.	Stay near the tag, keep the app open and send the model again.
Green off, red on steady, and the app cannot connect.	The tag is in its update mode, waiting for firmware over USB. Plug it into a computer and follow Firmware update over USB-C, or power-cycle it.
The app cannot load a model.	Update the firmware to the latest release first. See Update the firmware.

If none of this helps, the FAQ answers the common questions, and Support says where to ask: BrainChip’s Discord at https://discord.com/invite/9bmd9g52vn for help, and an issue at https://github.com/Brainchip-Inc/AkidaTag/issues for a bug.