EVAL-XXX-KH Datasheet, PDF (2/5 Pages) List of Unclassifed Manufacturers – KH SERIES BASIC EVALUATION KIT USER’S GUIDE

KH TRANSMITTER EVALUATION BOARD
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1. Battery - 3VDC (use a CR2032-style battery only)
2. Power Switch
3. Momentary Pushbutton - S0 (D0)
4. Momentary Pushbutton - S1 (D1)
5. Continuous Transmit Jumper
6. Transmit Enable Cut-Trace / Jumper (JP3)
7. Reverse-Polarity SMA Antenna Connector
8. KH Series Transmitter Module
9. 10-Position Address DIP Switch
KH RECEIVER EVALUATION BOARD
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1. Buzzer - D0
2. LED - D1
3. Battery - 3VDC (use a CR2032-style battery only)
4. Power Switch
5. Prototyping Area
6. KH2 Series Receiver Module
7. Reverse-Polarity SMA Antenna Connector
8. 10-Position Address DIP Switch
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THEORY OF OPERATION
TRANSMITTER EVALUATION BOARD
The transmitter board is powered by an on-board 3V CR2032 lithium battery. It
has two SPST pushbutton switches, the state of which is encoded into a data
stream by the module. If a switch is closed, the module will capture the settings
of the 10-position DIP switch address bits and pushbutton states for encoding
and transmission. Only the two switches that control the LED and buzzer on the
receiver board have been populated. The transmitter will transmit continuously
when any switch is closed or when Transmit Enable (TE) is pulled high (default).
If it is desired to control the TE line with external circuitry, then the trace marked
by JP3 can be cut and additional circuitry added.
RECEIVER EVALUATION BOARD
The receiver board is also powered by a 3V CR2032 lithium battery. The KH2
Series receiver exhibits a sensitivity of greater than -112dBm, so under optimum
line-of-sight conditions, the transmitter / receiver link can operate over distances
of up to 3,000 feet. The data recovered by the KH2 Series receiver is internally
decoded. If the settings of the 10-position DIP switch on the receiver board
match the address setting of the transmitter board, the data lines are updated to
match the state of the data lines (or pushbuttons) on the transmitter board. To
demonstrate this, one data line is used to drive a LED while another is used to
activate a buzzer. Switching transistors are used as drive buffers because the
KH2 receiver cannot directly source the current necessary to operate these
devices. This board has a prototyping area with all of the receiver lines brought
out to a header for easy access by external circuitry.
USING THE KIT
Using the kit is straightforward. Simply attach the antennas, turn on the power,
and press one or both of the buttons on the transmitter board. When S0 is
pressed, the buzzer will sound; when S1 is pressed, the LED will turn on.
DEVELOPMENT USING THE PROTOTYPING AREA
In addition to its evaluation functions, the receiver board may also be used for
actual product development. It features a prototyping area to facilitate the
addition of application-specific circuitry. This area has a connection to V_CC at the
top and ground at the bottom that can be used to power the added circuitry.
NOTE: The CR2032-style battery on the board has very low current capacity, with only
about 3mA available for external circuitry. If added circuitry requires a higher current, the
on-board battery must be removed and the board powered from an external source.
The holes are plated and set at 0.100” on center with a 0.040” diameter, making
it easy to add most industry-standard SIP and DIP packages to the board.
On the transmitter board, locations S2 to S7 are available for population of
switches or direct interface of logic leval inputs. On the receiver board, the data
lines from the decoder plus the PDN, and DATA lines from the receiver have
been wired out. This allows for easy access to connect external circuitry to the
modules, the encoder, and the decoder. Data line D0 is connected to the buzzer
and D1 is connected to the LED.
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