The Articul8 Hardware: v2.0

Improvements to our first design, new features, and next steps.

Posted by Articul8 on February 22, 2019

The New Boards Are In!

The second version of the Articul8 hardware has officially arrived in Canada after being printed in China. Before we get to soldering the components, we thought that it would be a good time to discuss the improvements we're making to the bands, and what's next.

The main new changes are that we've moved the motor drivers off of the main board and have created unique daughter boards that each control one motor. We also exchanged our Bluetooth Low Energy (BLE) chip for a Bluetooth Classic chip and upgraded our main crystal, the time keeper of the board. An on-off switch, micro-USB interfacing, and several other user experience changes were also made.

An Easier Development Experience

One important design criterion for the second version of the board was to make it easier to develop new software for. The success of our product is contingent on the quality of the software on it, and this quality is highly affected by the development environment. To improve this, an FTDI chip was used to allow programming of the board directly over a micro-USB connection. This will prove to be a great improvement, especially since this port is used for debugging communication. The device also charges over this one port, making an optimal experience by having everything in one place.

Gotta Go Fast

While our first board did meet the specification for communication speed that was initially selected, we realized that increasing the speed would allow for a much better user experience. Upon further development, it became clear that an increase in speed could be achieved in a cost-effective way by buying a slightly more expensive clock for the main board and by replacing the Bluetooth Low Energy chip with a Bluetooth one. These changes both will lead to a smooth fast data stream which can be leveraged for improved data processing, information latency, and feature set.

Conveniently, these changes will also increase the ease of development significantly. Both the Bluetooth Classic and the new clock frequency allow for more standard comnmunication practices to be used which results in improved support by Mac and PC development environments and personal device communication protocols.

Daughter Boards

The daughter boards are by far the most changed aspect of our design. The motors were placed in the back of these boards, with an I2C translation unit and motor driver on top. The boards were then all connected using the 4-pin I2C protocol, with the translators allowing extremely fast communication with the motor drivers. Previously we had used mutexes to communicate with the motors, which required the selection of a board to communicate to before sending it a command. Since the translators are now being used to spoof a different I2C address for each board, this communication time can be cut in half, and commands can be sent directly to the devices.