In order to use Carista, you must have an ELM327-compatible device (Bluetooth for Android and WiFi for iOS). This is a separate piece of hardware that you plug into your vehicle’s OBD2 port so that Carista can communicate with your vehicle. Carista requires an ELM327 v1.4 or newer device (v1.2 is also fine for plain OBD2 diagnostics, but not for customizations or advanced diagnostics). We do not make or sell any hardware; however, many online retailers like Amazon do, and we’re providing some links for your convenience (see below).
Disclaimer: due to differences between device manufacturers, we cannot guarantee that these will work. Please look at reviews for specific sellers, etc. and make your own decision. Specifically, most devices that claim to be v2.1 are fake and do not work.