User's Manual

Note d‘étude / Technical document :
URD1– OTL 5696.1– 003 / 72361 Edition 02
HILO 3G Application Note
17 January 2011 - Page 22 / 38
AT command AT+Ksleep can switch between the two sleep modes available for HiLo3G.
DTR input signal is internally pulled up to VGPIO with a 100KΩ, this result in 28μA of extra consumption
As CTS is active (low electrical level) once HiLo3G is switched on, RTS is also active (low electrical level), therefore
AT command AT+Ksleep can switch between the two sleep modes that are available for HiLo3G. The HiLo3G's firmware
allows the rise of CTS during the sleep state even when looped to RTS signal.
DCD and RI can stay disconnected and floating when not used. Otherwise use 100KΩ pull up to VGPIO.
Moreover this configuration does not allow the signaling signals as below:
• RI signal used when programmed to indicate an incoming voice or data call or SMS incoming etc…
• DCD signal used to signal the GPRS connections
• DSR signal used to signal the module UART interface is ON
• DTR signal used to prevent the HiLo3G module from entering into sleep mode
3.6 GPIO
There are three GPIOs available on HiLo3G. Customer application can directly use them through the appropriate AT
command as:
- Output: pin is set to High or Low state
- Input: pin is read on request and answer is given to the customer application
As input, different cases are possible to cover the maximum possibility of customer application:
• Synchronous answer to the AT command
• Asynchronous answer to the AT command. The customer application prior to the request has configured the GPIO to
react on falling/rising edges. The customer application is notified asynchronously by AT command answer when the
configured trigger occurs.
Figure 22: Programmable GPIO configurations
Thanks to some other special AT commands, GPIOs can for example be used:
1. Make an I/O toggling while the module is attached to the network
2. Make an I/O toggling when a programmed temperature is reached
3. As input to detect the presence of an antenna (with some external additional electronic)
4. As input to detect the SIM card presence …etc
3.7 ADC
There is one ADC input pin which can be used to read the value of the voltage applied. Following characteristics must be
fullfilled to allow proper performances:
• The input signal voltage must be within 0V and up to 2.1V
• The input impedance of the pin is 2KΩ
• The input capacitance is typically 53pF.
The AT command AT+KADC will return the voltage value with the following characteristics:
• 12 bits resolution
• Maximum sampling frequency is 2.4MHz.