Lucid Technologies ROCKET BEEPER RB02 User manual

ROCKET BEEPER
RB02
USER’S MANUAL
2023.11.07
Lucid Technologies
http://www.lucidtechnologies.info/
Email: [e-mail]
Copyright © 2023 by Lucid Technologies
All rights reserved
The information in this manual has been carefully checked and is believed to be accurate.
However, Lucid Technologies makes no warranty for the use of its products and assumes no
responsibility for any errors which may appear in this document. Lucid Technologies reserves the
right to make changes in the products contained in this manual in order to improve design or
performance and to supply the best possible product. Lucid Technologies assumes no liability
arising out of the application or use of any product or circuit described herein; neither does it
convey any license under its patent rights, nor the rights of others.

RB02, Rocket Beeper 2
Contents
Specifications & block diagram
Description
Battery requirements
Using the RB02
Attaching the RB02
Securing the battery
RB02 operation
Appendix A - Battery recommendations
Appendix B - Battery charger
Specifications
Mass
Approximately 9.75 grams, without battery
Dimensions
Diameter 24.5 mm
Length 51.6 mm
Compatible with BT-55 or larger body tubes
Power
3.1 to 4.2 volt lithium battery
JST PH2 connector
Audio output
Approximately 3550 Hertz at 12 volt supply
Beep rate 1 ±30% Hertz
Sound pressure level 108 dB at 10 cm
Figure 1

RB02, Rocket Beeper 3
Description
The RB02 has several advantages over other acoustic rocket finders. As shown in the block
diagram, the RB02 has a DC-to-DC converter that boosts the nominal 3.7 volts from a typical
single cell lithium battery to 12 volts. This means that the beeper will always operate at its
optimum voltage and produce a loud tone. The microprocessor controls the DC-DC conversion,
monitors battery voltage and light levels, and times the operation of the RB02. The beeper has a
built-in oscillator that produces a series of beeps at approximately 1 Hz - half a second on, half a
second off. When this document says the RB02 is beeping, that means it is producing a series of
beeps. A series of short beeps is easier for the human ear to locate than a constant shrill tone. The
RB02 uses several techniques to maintain operation as long as possible while not discharging the
lithium battery beyond the point that it can no longer be recharged.
Battery requirements
Batteries used with the RB01 are compatible with the RB02. The RB02 is sold with or without a
battery. Numerous rechargeable lithium batteries with JST PH2 connectors are available online. A
100 to 150 mAh battery will power the RB02 for several hours.
Figure 2

RB02, Rocket Beeper 4
Note the polarity of the battery connector (J1
on the circuit board). Lithium batteries with
JST PH2 connectors do not all have the
positive and negative in the same place.
Check your battery to be sure the positive
(red) and negative (black) are on the correct
sides. The connectors in the battery’s JST
plastic shell can be removed and reversed by
prying up the plastic retaining latches with
the tip of a sharp knife - like an X-Acto
knife. Note your battery charger will also
need to have matching polarities - the
charger will be damaged if the connected
battery is reversed.
To keep the battery from getting scratched by the wires on the bottom of the RB02 circuit board
you may want to glue a piece of cardboard on one side of the battery as shown in the picture on the
left. This picture also shows the correct location of the red and black wires in the JST PH2
connector.
Using the RB02
Attaching the RB02. The RB02 can be attached to your rocket via the “suspension” hole in the
circuit board. A flexible cord (such as kevlar string) passed through this hole will keep the RB02's
beeper pointed at the ground during recovery.
Securing the battery. The battery can be held against the bottom of the RB02 circuit board by a
rubber band wrapped around the circuit board. Both ends of a short rubber band go in slots on the
side of the circuit board, see Figure 2. The battery can be more securely attached with the
following methods. In addition to the rubber band, use double-sided foam tape on the bottom of
the circuit board to hold the battery in place. In addition to double-sided foam tape, use a short
piece of large diameter transparent heat-shrink over the RB02 circuit board and battery. Shrink it
to secure the battery in place then cut an access to the ON/OFF jumper. Be sure the heat-shrink is
transparent so that the light sensor will still work correctly.
RB02 operation. When you are ready to launch your rocket, move the jumper on J2 from the OFF
position to the ON position. Similarly, when you have recovered your rocket and want to turn off
the RB02 remove the jumper from J2. Stow the jumper in the OFF position so you don’t lose it.
The list below explains the actions of the RB02 after it is turned ON. Figure 5 shows these in flow
chart format.
1. The LED will blink twice.
2. The RB02 will beep for two seconds,
3. The LED will blink twice.
Figure 3. RB02 battery

RB02, Rocket Beeper 5
Figure 4. RB02 firmware flow chart
4. The microprocessor will check the battery voltage to confirm it is greater than the minimum
operating voltage of 3.1 volts. If the battery is 3.1 volts, the LED will rapidly flash 16 times,
then the RB02 will shut down. You will need to recharge the battery.
5. If the battery voltage is > 3.1 volts the RB02 will quietly wait one minute. This time allows you
to put the RB02 in the rocket, close up the nose cone and get the rocket on the launch pad.
6. After waiting for one minute, the RB02 will wait for a second minute if it is in the dark. At any
time during the second minute, if the RB02 is ejected from the rocket and senses daylight it will
begin to beep. ( Note that unpainted hollow plastic nose cones may allow enough light into the
rocket for the RB02 to sense daylight.) At the end of the second minute the RB02 will begin to
beep even if it is still in the rocket on the launch pad.
7. The RB02 will beep as long as the battery voltage remains > 3.4 volts. If it takes a long time to
recover the rocket and the battery voltage drops to less than 3.4 volts, the RB02 will shift to low
power mode.
8. In low power mode, the RB02 will alternately beep for 8 seconds then be quiet for 8 seconds.
During the quiet 8 seconds, if the microprocessor senses it is dark, the LED will flash. Low power
mode will continue until the battery voltage drops below the minimum operating voltage of 3.1
volts.
9. When the battery voltage drops below 3.1 volts, the LED will rapidly flash 16 times, then the
RB02 will shut down. Discharging a single cell lithium battery to less than 3.1 volts may cause it
to fail permanently.

RB02, Rocket Beeper 6
Figure 5. RB02 top view with battery. Figure 6. RB02 bottom view with
battery.
Problems and suggestions
If you have any problems with your RB02, or have suggestions to improve it, please contact:
[email protected].

RB02, Rocket Beeper 7
Appendix A
RB02 Suggested Batteries
YTKavq 3.7V 150mAh Battery 501227 Lithium Polymer
Ion Rechargeable Li-ion Li-Po Battery with 2P PH 2.0mm
Pitch Connector
https://www.amazon.com/gp/product/B08TTY1JCK/ref=
ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1
Voltage: 3.7V; Capacity: 150mAh;Maximum Charge
Voltage/Current: DC4.25V/75mAh
Package Content: 1 x Lithium Polymer Battery
Material: Lithium Polymer; Net Weight: 6g
Connector Type: 2P 2.0mm Pitch; Cable Length: 5cm / 2"
Size: 27mm x 12mm x 5mm/1.05" x 0.47" x 0.2"
Price: $9.69
YTKavq 3.7V 100mAh Battery 401129 Lithium Polymer
Ion Rechargeable Li-ion Li-Po Battery with 2P PH
2.0mm Pitch Connector
https://www.amazon.com/gp/product/B08TTP2X87/ref=
ppx_yo_dt_b_asin_title_o08_s02?ie=UTF8&psc=1
Voltage: 3.7V; Capacity: 100mAh;Maximum Charge
Voltage/Current: DC4.25V/50mAh
Package Content: 1 x Lithium Polymer Battery
Material: Lithium Polymer; Net Weight: 3g
Connector Type: 2P 2.0mm Pitch; Cable Length: 5cm /
2"
Size: 29mm x 11mm x 4mm/1.13" x 0.43" x 0.16"
Price: $7.99

RB02, Rocket Beeper 8
Appendix B
Battery Charger Module
The battery charger sold by Lucid Technologies is a modified commercial single cell lithium
charger module. Lucid Technologies adds a connector cable compatible with batteries for the
RB01 and RB02, and changes the max charge current to approximately 130 milliamps. The
charger uses a 5 volt input from a micro-USB connector. The Full LED may be either green or
blue.