The first step for the next FSE is practically done. The base board is designed and almost ready to get printed. The second edition of the board fixes some minor bugs and brings new features with. All this to give you the ability to let your creativity free during designing some powerful and useful embedded devices 🙂
The new version of the board is show below. A lot will look familiar to you.
One major new functionality is probably the I2C to PWM converter. I thought it is about time to get to know how I2C works and at the same time give you access to more PWM pins. The PCA9685 is an I2C-bus controlled 16-channel PWM controller. Each output has its own 12-bit resolution (4096 steps) fixed frequency individual PWM controller that operates at a programmable frequency from a typical 24 Hz to 1526 Hz with a duty cycle that is adjustable from 0% to 100%. This makes it possible to set the LED to a specific brightness value. All outputs are set to the same PWM frequency. Find more information in the IC’s datasheet.
A challenge for me this time was the tool change I had. I decided to go fully open source and migrate from Eagle to KiCad. Wasn’t an easy choice since both tools are quite different.
With the schematic editor of KiCad you can create your design without limit. There are no paywalls to unlock features. An official library for schematic symbols and a built-in schematic symbol editor help you get started quickly with your designs. KiCad’s PCB layout view lets you make professional PCB layouts with up to 32 copper layers. KiCad now has a push and shove router which is capable of routing differential pairs and interactively tuning trace lengths. The feature which amazes me most is the 3D viewer of KiCad which you can use to inspect your design in an interactive canvas. You can rotate and pan around to inspect details that are difficult to inspect on a 2D view. Multiple rendering options allow you to modify the aesthetic appearance of the board or to hide and show features for easier inspection. Here below is the 3D model of our next board.
This will be the board we use in the future, and you can begin programming for it now. Updates coming soon!