Dear Forum,
I would like to realise a project for an elderly person with bad eyesight. He would like to use Whatsapp for sending and receiving voice messages, primary from one contact.
Is it somehow possible to control an Android mobile with an Arduino and two pushbuttons? One button starts to play the received voice messages, the other button starts recording a voice message to a defined contact.
Any help or suggestions is highly appreciated, thank you.
Have a look at MIT App Inventor, with which you can create apps running on an Android phone. This app can communicate with an Arduino via Bluetooth. You need an HC-05 or HC-06 BT module. But before, verify (or ask on a dedicated forum) if App Inventor can do what you want on the smartphone.
presumably the purpose of using the arduino is to provide a more tactile keyboard that buttons can be found on more from feel than the glass buttons on a phone?
Whether or not you can get the phone to do exactly what you want is another matter.
I expect the phone would play the received voice msg okay but sending a voice msg might just open up the phone's built-in app which would require the user to use the screen, so no gain there.
Bluetooth is easy. Simple Android apps are easy. You will certainly be able to achieve something useful, but possibly not everything you want.
But as the others have suggested, HC-05 and MIT App Inventor are the things you need to explore.