User's Manual

URD1 – OTL 5696.1– 022 / 72740 Edition 0.4 HILONC- 3GPS APPLICATION NOTE
: Programmable GPIO configurations
By utilizing other special AT commands, GPIOs can be used to, for example:
1. Perform I/O toggling while the module is attached to the network.
2. Perform I/O toggling when a pre-set temperature is reached.
3. Serve as an input to detect the presence of an antenna (with some additional external power.)
4. GPIO2 serves as an input default
to detect SIM card presence …etc
.
3.7. ADC
The HILONC-3GPS has one ADC input pin which can be used to read the value of the voltage applied. The
following conditions must be met to ensure correct performance:
·
Input signal voltage must be within 0V to 2.1V.
·
Input impedance of the pin is
2KΩ
.
·
Input capacitance typically is 53pF.
The AT command AT+KADC will produce a voltage value with the following characteristics:
· 1
5 bits resolution
· Maximum sampling frequency
of 2.4MHz.
3.8. Backup Battery
3.8.1. Backup Battery Function Features
A backup battery can be connected to the module in order to supply internal RTC (Real Time Clock) when the
main power supply is removed. Thus, when the main power supply is removed, the RTC is still supplied with
power and the module keeps the time register running.
·
If
VBAT
< 3V, internal RTC is supplied by
VBACKUP
.
· If VBAT ≥
3V, internal RTC is supplied by
VBAT
.
3.8.2. Internal HILONC-3GPS Charging Function
HILONC-3GPS has a charging function that does not require any additional external power supply (power
supply for the charging is provided by the HILONC-3GPS).
Charge of the back-up battery occurs only when main power supply
VBAT
is provided.
Note d’étude / Technical document :
01/08/20111 - Page 20 / 41