User's Manual
Table Of Contents
- GC864 QUAD V2andGC864 DUAL V2Hardware User Guide
- APPLICABILITY TABLE
- 1 Introduction
- 2. Overview
- 3. GC864 Mechanical Dimensions
- 4. GC864-QUAD V2 / GC864-DUAL V2 Module Connections
- 5. Hardware Commands
- 6. Power Supply
- 7. Antenna
- 8. Logic Level Specifications
- 9. Serial Ports
- 10. Audio Section Overview
- 11. General Purpose I/O
- 11.1. GPIO Logic Levels
- 11.2. Using a GPIO Pad as INPUT
- 11.3. Using a GPIO Pad as OUTPUT
- 11.4. Using the RF Transmission Control GPIO4
- 11.5. Using the RFTXMON Output GPIO5
- 11.6. Using the Alarm Output GPIO6
- 11.7. Using the Buzzer Output GPIO7
- 11.8. Magnetic Buzzer Concepts
- 11.9. Using the Temperature Monitor Function
- 11.10. Indication of Network Service Availability
- 11.11. RTC Bypass Out
- 11.12. DAC Converter
- 11.13. ADC Converter
- 12. Assembly the GC864-QUAD V2 / GC864-DUAL V2 on the Board
- 13. Packing System
- 14. Conformity Assessment Issues
GC864 Hardware User Guide
1vv0300874 Rev.0 – 2010-01-25
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved. Page 35 of 64
9. Serial Ports
The serial port on the Telit GC864-QUAD V2 / GC864-DUAL V2 is the core of the
interface between the module and OEM hardware.
2 serial ports are available on the module:
• MODEM SERIAL PORT
• MODEM SERIAL PORT 2 (TRACE for debug)
9.1. MODEM SERIAL PORT
Several configurations can be designed for the serial port on the OEM hardware, but
the most common are:
• RS232 PC com port
• microcontroller UART @ 2.8V – 3V (Universal Asynchronous Receive
Transmit)
• microcontroller UART@ 5V or other voltages different from 2.8V
Depending from the type of serial port on the OEM hardware a level translator circuit
may be needed to make the system work. The only configuration that does not need a
level translation is the 2.8V UART.
The serial port on the GC864-QUAD V2 / GC864-DUAL V2 is a +2.8V UART with all the
7 RS232 signals. It differs from the PC-RS232 in the signal polarity (RS232 is
reversed) and levels. The levels for the GC864-QUAD V2 / GC864-DUAL V2 UART are
the CMOS levels:
Absolute Maximum Ratings –Not Functional
Parameter Min Max
Input level on any
digital pad when on
-0.3V +3.1V
Input voltage on
analog pads when on
-0.3V +3.0 V