Implementing a MATLAB digital filter or controllers in C++

Controllers and filters are often a good way to stabilise a system, condition a signal or make a system follow a reference. The usual approach is to model the system or signal in an application like MATLAB and then design a filter or controller. Either by applying design rules, some sort of optimisation algorithm or tuning parameters experimentally. When the design is finished the controller or filter is not ready for use yet. It is still necessary to realise it in practice. This is often done digitally on a micro controller or real-time computer. This article will describe a effective, open and fast approach to realising a filter or controller in C++.

Step responses of Butterworth Low-pass Filters
Step responses of Butterworth Low-pass digital filters with different cut-off frequencies

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Update Rooted Nexus 6P to Android 7.0 Nougat with FlashFire

Android 7.0 is out! I’m really wondering about the split view mode and the new notification. I wanted to upgrade my Nexus 6P as soon as possible. The update was not available as an OTA for my phone yet so I had to take a simple measure to make it available. Furthermore my phone is rooted so I had to use a flash tool or the adb/fastboot tools to upgrade. First, we will enable the update. Then we download it. Next we use FlashFire to flash the firmware to the device (dangerous). Finally we will hopefully try to boot into the newest Android version.

The steps below will most certainly work for all recent Nexus devices like the Nexus 6 and Nexus 5X. The older Nexus 5 is not supported officially so it will depend solely on community effort.

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