📡 Raspberry Pi GSM/GPRS/GNSS Bluetooth HAT Module SMS GPS UART SIM868 Based, Compatible with Raspberry Pi 4B/3B/3B+/2B/Zero/Zero W, Supports Phone Calls, Speaker, and Global Positioning System Data Transfer - by XYGStudy Review

I like the small size, good performance and good antennas included. I spent extra time getting the GPS to work while the cellular data was active, and after the GPS turned on, the cellular data stopped working. What the documentation doesn't say: You can't use the typical gps on command and the nmea search command. Instead, use the command AT+SGNSCMD=1.0 and wait for a GPS frame. See the simcom help manual for more information. You can get them from waveshare (dot com).

I operated the device for about 4 months in a sitting position with occasional use, powered by a stable power supply unit. Unfortunately it suddenly doesn't seem to work anymore and doesn't show up in dmesg or /dev/ anymore.

I was able to connect it to Arduino UNO and answer incoming calls. Please note that the Arduino requires a special library and the connection must be made with a pair of jumpers.

I use this so my house can text me for certain events. I don't use the data portion, I'm only planning on spending $5 a month to send text messages. With an additional antenna for outdoor mounting, it was reliable. The included antenna was fine too, but while I was in my garage messages were sometimes delayed as the radio reestablished contact.