–

–

–

–

6

7

The Prototyping Area

In addition to their evaluation functions, the boards may also be used

for actual product development. They feature a prototyping area for the

addition of application-specific circuitry. The prototyping area is the same

on both boards and contains a large area of plated through-holes so that

external circuitry can be placed on the board. The holes are set at 0.1" on

center with a 0.04" diameter, making it easy to add most industry-standard

SIP and DIP packages to the board. This circuitry can be interfaced with

the ES transmitter or receiver through the breakout header to the right. At

the bottom of this area is a row connected to the 5V power supply and at

the top is a row connected to ground.

headroom available for additional circuitry. If added circuitry requires a

higher current, the user must add an additional regulator to the prototype

area or power the board from an external supply.

Ground Bus

Regulator

+5 Volt Bus

Figure 5: The Development Board Prototyping Area

Using the Simplex Encoder / Decoder Section

The transmitter board features an MS Series remote control encoder with

two push buttons and the receiver board features a decoder with a relay

output and a buzzer. When a button is pressed on the transmitter board,

the status of both buttons is captured and encoded into a data stream

for transmission. The data recovered by the receiver is decoded and the

decoder’s outputs are set to replicate the states of the encoder, driving

either the buzzer or the relay.

To activate this area of the board, the

module DATA line must be routed to

the encoder / decoder. Configure the

transmitter board for encoding and

transmission by placing a jumper across TX

DATA and ENCODER and across TX PDN

and PDN ENC on header TS1. Configure

the receiver board for reception and

decoding by placing a jumper across RX

DATA and DECODER on header TS2.

Once the boards have been configured, place the receiver board on a flat

surface and turn it on. Turn on the transmitter board and press button S0.

You should hear the buzzer on the receiver board sound. Walk away from

the receiver to ascertain the useable range of the link in the environment.

Button S1 activates the relay on the receiver board. The relay’s SPST

contacts can be connected at J2. Any device up to 5A at 30VDC / 120VAC

may be switched through the relay. An external siren or light can be

connected to aid range testing if the on-board buzzer is not loud enough.

Using the Data Squelch Circuit

A data squelch circuit is provided on the receiver development board.

This circuit is used to add both hysteresis and squelching capabilities as

detailed in the ES Series Receiver Data Guide. Since the ES Series receiver

output is not internally squelched, its output continually switches when no

transmission is present. This can cause interrupts and buffer overflows in

external circuitry. A squelch circuit helps eliminate this noise by providing

a qualification threshold for incoming data based on signal strength. This

circuit is not a substitute for robust protocol since squelch can be broken

by unintended interference.

TS1

TX

RX

TS2

SQ. DATA

NC

AUDIO REF

AUDIO

RSSI

RX DATA

RX DECODER

RX PDN

PDN ENC

TX PDN

PDN RS232

TX RS232

TX DATA

TX ENCODER

/CLK

/CLK SEL

LO V DET

NC

GND

TS1

TX

RX

TS2

SQ. DATA

NC

AUDIO REF

AUDIO

RSSI

RX DATA

RX DECODER

RX PDN

PDN ENC

TX PDN

PDN RS232

TX RS232

TX DATA

TX ENCODER

/CLK

/CLK SEL

LO V DET

NC

GND

Figure 6: Jumper Configuration