and is compatible with the SIM908 GSM/GPRS module that adds a GPS receiver. Also on board this shield are a pair of 1/8″ audio jacks, perfect for connecting a microphone and headphones.

The heart of the build is a NEO-6M GPS module which features a dedicated pulse per second (PPS) pin. The ESP8266 combines the timestamp from the GPS messages and the PPS signal to synchronize ...