MIX Modem - GSM
User Manual V.1.1
Pag. 26
Subject to change without prior notice
The GIPO related AT commands are the following: AT^SPIO, AT^SCPIN, AT^SCPOL,
AT^SCPORT, AT^SDPORT, AT^SGIO, AT^SSIO.
When the MTX-65I starts up, all GPIO pins are set to high-impedance state after initializing, so, they’re
connected internally with a pull-down resistor. This is necessary to keep these pins from floating or
driving any external devices before all settings are done by AT command (at least AT^SPIO,
AT^SCPIN), and after closing the GPIOs again
.
All general purpose IO (GPIO) is programmable by the user.
GPIO is programmable for the following features:
• An input or output
• Level-sensitive or transition-sensitive
• Open drain or direct drive
• Polarity (inversion)
• Internal pull-up resistors
3.7.5. Analog-to-Digital Converter (ADC
)
The ADC of the MIX MODEM GSM consists of 2 independent, unbalanced, multiplexed analog inputs
that can be used for measuring external DC voltages in the range of 0mV…+2400mV. The ADC has a
resolution of 12 bits.
Use the command AT^SRADC described in [1] to select the analog inputs ADC1_IN or ADC2_IN, to set
the measurement mode and read out the measurement results. The measured values are indicated in
mV.
There is no out of range detection. Voltages beyond these limits cannot be measured:
• Underflow: Values ≤ -25mV
• Overflow: Values > 2425mV
The sample period is adjustable from 30s up to 100ms by AT^SRADC Only during sample time
(ts~400µs) the S&H Switch is closed.