Develop 4-channel datalogger

The scope of this project is to develop a 4-channel datalogger and Android application to control it. Requirements for the characteristics of the analog inputs: - number of analog inputs - 4; - signal sampling frequency - 50 kS / s per channel; - 14 bit ADC (better to use 16 bit ADC); - input voltage range: 2 inputs with a range of ± 20 V, and 2 inputs with a range of ± 200 V; - multiplexing of all input signals to one ADC is possible; but preferable to use separate ADCs for each of inputs. The datalogger should record signals into an internal memory (microSD memory card). Device must provide monitoring of signals before recording and during recording. Monitoring should be done using a specialized Android application. Communication with Android application device occurs via WiFi communication channel: either through a third-party WiFi router, or by connecting to a WiFi access point on the device itself. To set up WiFi communication between the logger and Android application, it is preferable to use the BlueTooth communication channel. After recording is stoped, the logger should send the saved data to the Android application. The application should pack the received data in a certain way, and then send it to a remote server. The server will provide the response in the form of HTML document that needs to be displayed in the Android application. The whole process should be controlled from the Android application. Preferably freelancers having experience with development of dataloggers/oscilloscopes.