Assembly Manual

Mike Fortney

04/09/2004

CricketSat Receiver

Index• Parts List• Parts Layout• Completed Board - Top View• Circuit Board Assembly• Enclosure Modifications• Final Assembly• Testing• Troubleshooting• Schematic• More sections to be added: Features, Specifications, Circuit Description,

Normal Operation, Data Logging with a Computer, Optional Accessories

Parts List (1 of 2)• Verify that you have the following parts in your kit. If not send an email to

mfortney@emba.uvm.edu

• Use the photo two pages ahead to identify parts

• White plastic enclosure with built-in speaker

• Antenna

• Green printed circuit board

• 9-Volt battery

• 9-Volt battery snap connector

• Power switch

• RF receiver module

• LM386 IC chip

• 8-pin DIP socket

• 5-Volt regulator (black 3-pin device)

• Red and green LEDs

Parts List (2 of 2)• Two black tubular LED standoffs

• Protection diode

• Audio jack

• External power jack

• Blue 220uF coupling capacitor

• Five small yellow 0.1uF capacitors

• Larger yellow 10uF capacitor

• Volume control potentiometer

• 10 ohm resistor, brown-black-black-gold

• Two 750 ohm resistors, violet-green-brown-gold

• 180K ohm resistor, brown-gray-yellow-gold

Parts Layout

J3 not installed

Completed Board - Top View

Data LED (Red)

Audio Data Jack Antenna Coax Cable Power Jack

Power LED (Green)

RF Receiver Module

Power Switch

Battery Leads (Red - Right Black - Left)

5-Volt Regulator (flat side outward)

Coupling Capacitor

Speaker Leads (Non-Polarized)

LM386 Amplifier IC

Volume Control Potentiometer

Twisted Braid

Circuit Board Assembly (1 of 4)• Refer to layout images on previous pages

• Install the parts in the following order:

• Resistors– R1 & R2, 750 Ohm, violet-green-brown-gold

– R3, 180K Ohm, brown-gray-yellow-gold

– R5, 10 Ohm, brown-black-black-gold

• 0.1uF capacitors (C1, C3, C4, C5, C7)

• D1 diode, banded side is negative (-)

• R4, volume control

• C2, 10 uF capacitor, banded end is positive (+) , mount close to the board

Circuit Board Assembly (2 of 4)• S1, power switch

• IC socket, 8-pin DIP, notch towards R3

• U3, LM386 IC, notch towards R3

• U1, 5-Volt regulator, flat side facing C1, mount as close to the board as possible

• C4, 220 uF capacitor, banded end is negative (-), indented end is positive (+)

Circuit Board Assembly (3 of 4)• J1 & J2, power and audio jacks

• U2, RF receiver module, mount as close to the board as possible

• D2 & D3, red and green LEDs, mount with standoffs, tight to the board– Positive LED lead is the longer of the two leads

LEDs with standoffs

Circuit Board Assembly (4 of 4)• 9-Volt battery clip, red (+) and black(-) wires

• Antenna coax cable– Cut to 2 inch length

– Strip back insulation 1/2”

– Separate braid from center conductor, twist into a second wire

– Solder into board as shown below and in layout image

Twisted Braid in big hole

RF Receiver Module

Center conductor this hole DO NOT use this hole

Top of edge of board

Enclosure Modifications(1 of 2)• Remove the two screws from back of the enclosure and remove the back cover

• Drill holes where indicated by the black dots shown below

• Center punch the hole first to insure proper alignment

• Drill holes using a 1/8 inch drill bit

1/8” holes for the LEDs

Enclosure Modifications(2 of 2)• Cut out the blacken shapes shown below using a nibbling tool, file or a saw• Remove the template stickers once complete and clean rough edges with a file

Remove material

Remove material

Final Assembly(1 of 2)• Remove two circuit board mounting screws from enclosure• Solder speaker wires to circuit board • Mount antenna into center slot and tighten into place

Route battery cables Circuit board mounting screw

Antenna slot

Guide post and hole

Guide post and hole

Circuit board mounting screw

Final Assembly(2 of 2)• Fit circuit board into place in following sequence

– Use previous diagram to aid in this assembly– Bend RF receiver module slightly towards antenna coax cable – Lower into place, and mate switch lever with plastic thumb slider piece on

inside of enclosure– Align and lower circuit board guide holes over enclosure vertical guide

posts– Press and wiggle circuit board until LEDs pop through holes of front of

enclosure– If problem seating board, check that coax cable is not between RF module

and speaker. If so, move cable, and repeat above steps.– Secure circuit board with two screws

• Route battery cable, but DO NOT install the battery yet• Attach back of enclosure and secure with screws

Testing• Slide power switch all the way up. It is a three-position switch with

only the top position as “ON”• Using a multimeter, perform a short circuit test on the battery clip,

reverse the leads and repeat. You should measure no values less than 5K ohms.

• Attach the battery and its cover• The unit should be “ON” indicated by the green LED• The red LED may briefly flash as the unit is switched on• Turn the volume control to a mid position and you should hear a hiss

from the speaker• Test the unit with a CricketSat. The red LED should mimic the

CricketSat LED at distances of 25 to 100 feet

Troubleshooting

• No sound or lights, no smoke– Try a new battery

– Insure that slide switch is working properly

– Check if battery leads correctly attached to board, red +, black -

– Check if D1 diode is properly installed, white band -

– Check if amplifier IC and RF receiver modules installed properly

• No sound, but lights– Turn volume control to a median setting. Should hear hissing

sound

• Does not receive CricketSat tone or pulses– Receiver module may be faulty or need re-tuning