Hardware Guide
Table Of Contents
- Introduction
- 2. Overview
- 3. GE865 Mechanical Dimensions
- 4. GE865 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. Indication of network service availability
- 11.9. RTC Bypass out
- 11.10. External SIM Holder Implementation
- 12. DAC and ADC section
- 13. Mounting the GE865 on your Board
- 14. Packing system
- 15. Conformity Assessment Issues
- 17. Document History
GE865 Hardware User Guide
1vv0300799 Rev.15– 2012-04-23
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 22 of 77
5.3. Resetting the GE865
5.3.1. Hardware Unconditional restart
WARNING:
The hardware unconditional Restart must not be used during normal operation of the device
since it does not detach the device from the network. It shall be kept as an emergency exit
procedure to be done in the rare case that the device gets stacked waiting for some network or
SIM responses.
To unconditionally reboot the GE865, the pad RESET# must be tied low for at least 200
milliseconds and then released.
The maximum current that can be drained from the RESET# pad is 0,15 mA.
NOTE:
Do not use any pull up resistor on the RESET* line nor any totem pole digital output. Using pull
up resistor may bring to latch up problems on the GE865 power regulator and improper
functioning of the module. The line RESET* must be connected only in open collector
configuration.
TIP:
The unconditional hardware restart must always be implemented on the boards and the software
must use it as an emergency exit procedure.
A simple circuit to do it is: