DNT500
2008 by RF Monolithics,
Inc.
16
M-0500-0000 Rev D
3.2 Module Interface
Electrical connections to the DNT500 are made through the I/O pads and through the I/O
pins on the DNT500P. The hardware I/O functions are detailed in the table below:
Pad
Name
Description
1
RSVD
Reserved pad. Leave unconnected.
2
RSVD
Reserved pad. Leave unconnected.
3
ADC_REF
ADC supply and external full scale reference voltage input. Voltage range is 2.4 to 3.3 Vdc.
Connect pad 34 to this input to reference the ADC full scale reading to the module’s 3.3 V
regulated supply.
4
RSSI
Analog voltage proportional to received signal strength, range 0 to 3.3 V.
5
GPIO0
Configurable digital I/O port 0. When configured as an input, an internal pull-up resistor can be
selected and interrupt from sleep can be invoked. When configured as an output, the power-on
state is also configurable.
6
GPIO1
Configurable digital I/O port 1. Same configuration options as GPIO0.
7
GPIO2
Configurable digital I/O port 2. Same configuration options as GPIO0.
8
GPIO3
Configurable digital I/O port 3. Same configuration options as GPIO0.
9
PWM0
Pulse-width modulated output 0 with internal low-pass filter. Provides an 8-bit DAC resolution.
10
PWM1
Pulse-width modulated output 1 with internal low-pass filter. Provides an 8-bit DAC resolution.
11
SLEEP
Default functionality is active high module sleep input. When switched low after sleep, the
module executes a power-on reset.
12
ADC0
10-bit ADC input 0. Full scale reading is referenced to the ADC_REF input.
13
ADC1
10-bit ADC input 1. Full scale reading is referenced to the ADC_REF input.
14
ADC2
10-bit ADC input 2. Full scale reading is referenced to the ADC_REF input.
15
EX_SYNC
Optional rising-edge triggered input for synchronizing co-located base stations. See External-
SyncEn on Page 25 for additional details.
16
DIAG_TX
Diagnostic output (for factory use).
17
DIAG_RX
Diagnostic input (for factory use).
18
/CFG
Protocol selection input. Leave unconnected when using software commands to select trans-
parent/protocol mode (default is transparent mode). Logic low selects protocol mode, logic high
selects transparent mode.
19
VCC
Power supply input, +3.3 to +5.5 Vdc.
20
GND
Power supply and signal ground. Connect to the host circuit board ground.
21
GND
Power supply and signal ground. Connect to the host circuit board ground.
22
GPIO4
Configurable digital I/O port 4. When configured as an input, an internal pull-up resistor can be
selected. When configured as an output, the power-on state is configurable.
23
GPIO5
Configurable digital I/O port 5. Same configuration options as GPIO4.
24
RSVD
Reserved pad. Leave unconnected.
25
ACT
Data activity output, logic high when data is being transmitted or received.
26
/DCD
Default functionality is data carrier detect output, which provides a logic low on a remote when
the module is locked to FHSS hopping pattern and logic low on a base station when at least
one remote is connected to it.