e-Gizmo MUDT-433 User manual

©2013 e-Gizmo Mechatronix Central
Page 1 of 5 pages Multi Channel UHF Data Transceiver
e-Gizmo Multi-channel UHF Data Transceiver
MUDT designed as a UART wireless cable re-
placement operating in !xed 9600 bps, half duplex,
no hardware handshake mode. As long as your
data packet does not exceed 96 bytes, your own
code can be totally oblivious to its presence. Your
UART code services wont need any extra handling
for its use. In general, UART code services that
work with direct cable connection under the just
mentioned operating parameters, will work as well
when the cable is replaced with the MUDT.
Multi-Channel Feature
The Multi-channel UHF Data Transceiver MUDT-
433 transmits and receives at ISM 433MHz RF
band, and the MUDT-315 operates at ISM 315MHz
band. MUDT frequency channel can be altered by
the user if it so desired by installing (or removing)
a jumper at the channel select port. This is a 4-bit
channel selection, allowing each module 15 chan-
nels with 400kHz.spacing.
Channel selection control can be passed on to the
host controller by removing all jumpers and con-
necting the MUDT channel port to a 4-I/O port of
the host controller.
RSSI Received Signal Strength Indicator
By forcing the MUDT RSSI control pin to logic 0,
the MUDT will append the RSSI value at the end of
every received data packet. You can use the RSSI
to determine whether enough signal strength is
available for a given installation that will ensure a
reliable RF link. You can also use the feature as a
rudimentary RF distance indicator or locator, albeit,
keep in mind the signal strength is affected by so
many things, hence, accuracy will be non-existent.
Frequency Range :
431.1 MHz  437.3 MHz
Channel Separation:
400kHz
Modulation:
FSK
RF Output power :
+10 dbm (10mW) typical
Rx sensitivity :
-105dbm
UART Baud Rate:
9600bps
Maximum Packet Size:
96 bytes
Operating Voltage:
5V/3.3V jumper selectable
Current Consumption TX:
36mA @ 5V
Current Consumption RX:
23mA @5V
Transmit to Receive latency :
20-30ms
RSSI :
150-635, with 635 corresponding to
-38dbm antenna RF input signal strenght
e-Gizmo MUDT-433, MUDT-315
Multi-Channel UHF Data Transceiver
Hardware Manual
Rev. 1r0
SPECIFICATIONS
Figure 1. The Multi-Channel Data Transceiver
is available in 2 variants  MUDT-433 operates
at ISM 433MHz, while MUDT-315 works at ISM
315MHz.
www.e-gizmo.com

©2013 e-Gizmo Mechatronix Central Page 2 of 5 pagesMulti Channel UHF Data Transceiver
Vcc
GND
TX
RX
LOC
D3
D2
D1
D0
JP2
Vcc= 3V3
P2
CHANNEL SELECT
PORT
P1
HOST I/F
PORT
CIRCLE DENOTES
PIN No. 1
GND
SMA CONNECTOR
OR WIRE ANTENNA
Figure 3. At your option, you can install an SMA
type RF connector (2a) at the J1 RF port. Or you
can directly solder a suitable antenna, either per-
pendicular (2b), or along the PCB plane (2c). The
PCB provides little mechanical support for a rigid
antenna, hence use only with additional support,
or when the MUDT, together with the antenna, is
housed in a protected (not metal) enclosure.
(a)
(b)
(c)
J1 - RF/ANTENNA port
JP2 - Power Supply voltage selection.
Open circuit - 5V
Shorted - 3.3V
P1 - Host Interface
Pin ID Description
1 LOC RSSI enable, active low
2 RX Rx data input
3 TX Tx data output
4 GND Ground
5 VCC +3.3v/5V Power Supply (see text)
P2 - Channel Select
Pin ID Description
1 D3 Channel Select MSB 3
3 D2 Channel Select Bit 2
5 D1 Channel Select Bit 1
7 D0 Channel Select LSB 0
note: Pin 2,4,6,8 - GND
Figure 2. Location of connectors, jumpers, and major parts.

©2013 e-Gizmo Mechatronix Central
Page 3 of 5 pages Multi Channel UHF Data Transceiver
Vcc
GND
TX
RX
LOC
DIO RXD TXD GND Vcc
HOST MICROCONTROLLER
Vcc
GND
TX
RX
LOC
DIO RXD TXD GND Vcc D0 D1 D2 D3
HOST MICROCONTROLLER
APPLICATION INFO
The MUDT will work with any microcontroller MCU
of your choice, including the gizDuino series. A
hardware UART is a necessary feature (advance
programmers, of course, can do it even without
hardware UART). It will work equally well with
either a 5V or 3.3V MCU. Keep in mind a jumper
must be installed across JP2 if the MUDT is run on
a 3.3V based MCU circuit.
Channel Selection.
The MUDT-433 is optimized for operation in the
433.98MHz (Channel 8, jumper on D3 only) set-
tings. Likewise, MUDT-315 works best when set
to channel 8. There will be slight degradation in
the performance, worsening further as the chan-
nel is set further away from channel 8. The effect,
however, will be barely noticeable if the MUDT is
operated at short distances away from each other
(not more than 200 meters).
Therefore, if your application has no need to
change channel, it is best to keep the default chan-
nel 8 settings.
To select a different channel, simply install the
jumpers corresponding to the desired channel. In
environment where a number of these transceivers
in use are within range, select channels separated
by at least two slots to minimize possible interfer-
ence from other pairs in the vicinity.
Channel selection can be transferred under host
MCU control by connecting the assigned control
I/O of the host MCU to the channel select port,
as shown in !gure 5. Needless to say, you have
to remove all the jumpers installed on it, not just
for the sake of correct operation, you cant install
anything else anyway if the jumper are installed.
Note that the rule of channel selection is reversed
logic, thats it, a logic 0 input is read as logic 1 by
the MUDT.
Figure 4. An interfacing wiring example with a
Host Controller. LOC connection is optional and is
needed only if the RSSI feature is used.
Figure 5. Channel selection can be put under
MCU control. Four MCU I/Os selects the de-
sired channel on the !y.

©2013 e-Gizmo Mechatronix Central Page 4 of 5 pagesMulti Channel UHF Data Transceiver
Data size and Data Integrity
A data packet is a group of data that is sent togeth-
er in a single transmission. The MUDT is capable
of data payload of up to 96bytes per packet. This
should be more than suf!cient for a vast majority
of control applications. If large chunk of data need
to be transferred via the MUDT, the host controller
must break this down into packets not exceeding
96 bytes.
Furthermore, data integrity checking is weak in
the MUDT. If high accuracy data transfer is re-
quired, data integrity checking, such as checksum
or crc method, must be performed by the host
controller.
RSSI
Pulling the LOC (RSSI) control to logic 0 enables
the RSSI feature of the MUDT. RSSI, which stands
for Received Signal Strength Indicator, is a meas-
ure of how strong the transmitting RF signal is as
received by the MUDT.
RSSI is measured when the transmitting side
sends a packet. Remember, you cannot meas-
ure the RSSI if the transmitter is OFF. The RSSI
information is then appended to the received data
packet, and is presented in !xed length 6-byte
ascii format as follows:
LF + r+ RSSI Value (3digit) + CR
Example: RSSI = 349
LF r RSSI (example 349) CR
0x0A 0x72 0x33 0x34 0x39 0x0D
Communications Parameters
Baud Rate: 9600bps
Data: 8 bits
Stop Bits: 1
Parity: None
Handshake: None
PCB ARTWORKS
COMPONENT LAYOUT
COPPER PATTERN BOTTOM SIDE
(VIEWED FROM THE TOP SIDE)
COPPER PATTERN, TOP SIDE

©2013 e-Gizmo Mechatronix Central
Page 5 of 5 pages Multi Channel UHF Data Transceiver
Figure 6. Schematic Diagram of the UHF Multi-Channel Data Tranceiver MUDT.