The CC3200 Wi-Fi SensorTag was officially released towards the end of last month. Being super excited about its small form factor and not having to bridge it to an internet gateway like the CC2650 SensorTag,
I ordered one along with the Watch DevPack, to aid in debugging. I also ordered a Debug DevPack, but since the Wi-Fi SensorTag firmware has not been released, I’ve left connecting it for later. This writeup is based on TI SensorTag documentation and playing with the tag. If you find errors or questions, please comment below or post the question in the SensorTag sub-forum.
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- Watch DevPack Interface
- Sensortag Initial Start-up
- Turning the SensorTag On/Off
- Toggling between AP and Station Mode
- Over the Air(OTA) Firmware Update
Watch DevPack Interface
The above image shows the SensorTag with the Watch DevPack. The DevPack is just a display which is a Sharp Memory LCD. The LCD is a Polymer Networked Liquid Crystal(PNLC), which is very reflective and mirror like. I wish TI went with the TFT version of the display. The PNLC is very hard to read.
The DevPack mounts behind the SensorTag via a high density connector. Removing the red silicone sleeve exposes the connector. The DevPack also comes with an extra sleeve which can be cut to fit the display outline.
For the moment, I’ve found that the red protective sleeve can slide over the LCD, with a tiny bulge. In any case, I plan to use the screen for debugging and leave it covered most of the time.
Pressing the power button starts up the tag. When the SensorTag is first turned on, it boots up with version 0.98a. This is the factory default firmware and starts up in Access Point(AP) mode. The display shows the Wi-Fi SSID that can be used to connect to the tag – SensorTag-A3.
You can now use the phone application to connect to the SensorTag. The first thing the application will ask you to do is to upgrade the firmware via Over the Air(OTA). Connecting a system to a known Wi-Fi network is known as provisioning. I tried provisioning the SensorTag using the factory firmware, but was not successful. Once the tag firmware was updated to the latest version, provisioning was successful. The latest firmware as of today is 1.003.
Turning the SensorTag On/Off
The SensorTag can be turned on by pressing either of the two buttons. To turn off the SensorTag, press the power button for five seconds. If the Watch DevPack is present, the time for button press is displayed as:
BTN -U- [3 s]
The “U” stands for User. If the power button is pressed, “P” gets displayed as:
BTN –P [3 s]
If both buttons are pressed, you will see:
BTN -UP [3 s]
Toggling between AP and Station Mode
Most of the time the Wi-Fi SensorTag will be used in Station mode, which means it connects to a local Wi-Fi network. However, there are times that you would want the SensorTag in AP or Access Point mode. This allows for changing properties or performing a firmware update over the air.
To toggle, press the user button for 5 seconds. You should hear the tag beep. If the Watch DevPack is present, you will see “WLAN toggle” displayed as shown below:
Restoring Factory Default Firmware
If anything goes wrong with your provisioning process or OTA firmware update, don’t panic. The SensorTag can easily be restored to factory by pressing the POWER and USER button for 6 seconds. This will restore firmware to 0.98a. Note that I was not able to force a factory reset if the firmware was already at 0.98a.
- If the tag has never been provisioned, it should come up in AP mode, ready for provisioning.
- If the tag has already provisioned before, press the USER button until you head a beep to switch to AP mode.
- Go to the phone’s Wi-Fi settings and select the SensorTag.
- Open the application and select the discovered SensorTag.
- This will bring up a new menu. Select “Wi-Fi Setup” and put in the Wi-Fi details.
- The tag will now start provisioning itself to the new network.
- After provisioning, you can view SensorTag details ans sensor data by using the phone application.
Over the Air(OTA) Firmware Update
OTA updates are seamless and the application guides you through it. The following images show the SensorTag side, while the phone application tries to update it.
The following sequence of events take place on the phone application side: