This is in continuation from my previous post at Safe & Sound - The Companion IoT Jacket #11: An Energy Harvesting Display


In this post, I add a Power Pack based on the Element14 and Texas Instruments Fuel Tank Booster Pack and the Wireless Charging Kit from Texas Instruments and Wurth Electronics.




The Third Module: Qi Power Pack

The last piece of my design is the power pack for the Sensors and Communications Core.


The Fuel Tank booster pack has the ability to manage the Li-Ion battery and provide regulated 5.0V, 3.3V along with battery gauging. Let's take a look at the design process.


a. Testing Charging

The first step in making the power pack is to see if the wireless charger works with the Fuel Tank. The jumpers on the Qi receiver were configured to provide 5V and connected to the Fuel Tank. The test setup is as follows.


Success. The systems can work but the next issue is to be able to connect it with the sensors core.


b. Connections

As discussed before, the headers were left exposed in the enclosure for the Sensors and Communications Core and can mate with the booster pack.


This eliminates the need for cables to connect the two.


c. Enclosure

The final enclosure follows suite with the rest of the enclosures and is design to be press fit.


The headers are exposed and designed to mate with the Core module.

d. The software

The code for the Fuel Gauge is similar to what was done at [Firecracker Analyzer] Wireless sensor Node part II & Setting up a solar Fuel Booster Pack A dedicated task talks to the Fuel Tank Booster Pack and gets relevant information. This information is relayed to a battery service notification service via BTLE and the display via UART


The code will be made available on GitHub with the link provided in the final blog post.



The Qi Charging Booster Pack adds a layer of simplicity to the entire design. The pack can be charged wirelessly and connected simply by plugging it into the Core module.

The last challenge is to put humpty dumpty together and present the final wearable.