“Are you thinking about make an Android app for arm robot with BLE? With this project you can understand how to work BLE and control it.
ARM Robot
This type of robotic arm has been selected for its simplicity and you can find it in some open publications. This type of robot has 3 degrees of freedom and 1 axis of action or work. Each of its joints works using a stepper motor, so it is a good practice to learn to control this type of motor using any of the commercial controllers, later on, I will tell you which one is used in this practice.
The Bast BLE is the new Feather family member with Bluetooth Low Energy in my projects because it is open-source, has native USB support featuring the nRF52840! It’s our take on an all-in-one Arduino-compatible + Bluetooth Low Energy with built-in USB plus battery charging. With native USB it’s even ready to join the CircuitPython party.
Bast BLE will accompany you in your most demanding projects. This board features a Nordic Semiconductors nRF52840 microcontroller, a 32-bit ARM® microcontroller that features low-power Bluetooth communication, NFC pairing, and powerful 1Mb FLASH memory internal + 1Mb Flash external and 256Kb of RAM for larger programs.”