Circuit connection diagram between TC35I and microcontroller

The TC35I module is a dual-band 900/1800 MHz highly integrated GSM  module launched by Simens. Its compact design and low power consumption provide a cost-effective solution for many communications applications. It supports EGS900 and GSM1800 dual-band. The data transmission content supports voice, data, short message and fax services. The communication interface uses RS232 (two-way transmission of instructions and data). The power supply uses a single power supply with a voltage of 3.3 V~5.5 V. It is suitable for The scope includes: low-power communication equipment for portable computers, telemetry and remote sensing, telematics and communications and other industrial fields. The circuit connection diagram between TC35I and microcontroller is shown in the figure.