arduino Lego car model controlled over bluetooth with android app developed with MIT app inventor
Tutorial: https://www.hackster.io/Notthemarsian/take-control-over-lego-power-functions-ee0bfa
Legocar_v3_bluetooth folder containing Arduino Uno .ino file (source code)
fritzing diagrams folder containing .fzz file plus PDFs of schematics and breadboardview
android app folder containing:
Arduino_car_RC_bluetooth.apk app which can be emailed to phone and installed (you will need to change the setting on your phone to allow installation of non-market applications) Or just download the finished app from Google Play (free): https://play.google.com/store/apps/details?id=appinventor.ai_notthemarsian.Arduino_car_RC_bluetooth
Arduino_car_RC_bluetooth.aia contains source code that can be loaded into http://ai2.appinventor.mit.edu (you have to log in with your google-account and then choose Projects -> Import from my computer (aia)) Or just follow the link to the project on the MIT app inventor 2 gallery: http://ai2.appinventor.mit.edu/?galleryId=5963827980271616