background image

3.

Know your U4B

U4B is a 33.0 x 12.7mm PCB, using 0.6mm thick FR4 PCB for low weight. SMD components are 
mounted on both sides of the PCB. 

U4B hardware Rev 1.00

5

Summary of Contents for U4B

Page 1: ...U4B U4B Ultimate4 Balloon tracker Hardware manual U4B hardware Rev 1 00 1 ...

Page 2: ... Contents Contents 2 1 Introduction 3 2 SAFETY FIRST 4 3 Know your U4B 5 4 Parts list 6 5 Track layout 7 6 GPIO pins 8 18 pad locations 7 7 Parts layout top side 8 8 Parts layout bottom side 8 9 Schematic 9 10 Circuit explanation 10 11 Basic flight connections 12 12 Resources 13 13 Document Revision History 13 U4B hardware Rev 1 00 2 ...

Page 3: ...terface for configuration programming and easy firmware update just copy the new firmware file into the apparent USB Flash drive Simplest possible operation Just connect to U4B with a PC terminal emulator and configure it with your callsign Register the flight name details and channel on the QRP Labs website Fly More flexible and advanced features U4B contains a wealth of flexibility and hardware ...

Page 4: ...peated objection to high altitude ballooning is that it s a danger to aircraft Having spoken to numerous commercial and private pilots about this I have yet to meet one who did other than laugh at the thought of something that tiny and delicate being any kind of danger to an aircraft Modern aircraft simply have too many built in redundant systems and safety features over engineering etc for such a...

Page 5: ...3 Know your U4B U4B is a 33 0 x 12 7mm PCB using 0 6mm thick FR4 PCB for low weight SMD components are mounted on both sides of the PCB U4B hardware Rev 1 00 5 ...

Page 6: ... 2012 Inductor R1 1K 0402 Resistor R2 22K 0402 Resistor R3 1 5K 0402 Resistor R4 22K 0402 Resistor R5 100K 0402 Resistor R6 280K 0402 Resistor R7 22K 0402 Resistor R8 22K 0402 Resistor R9 22K 0402 Resistor R10 22K 0402 Resistor R11 1 5M 0402 Resistor R12 100K 0402 Resistor R14 100K 0402 Resistor R15 5 6K 0402 Resistor R19 1K 0402 Resistor T1 SI1967DH T1 E3CT ND SOT363 Dual MOSFET transistor TCXO 2...

Page 7: ...5 Track layout 6 GPIO pins 8 18 pad locations U4B hardware Rev 1 00 7 ...

Page 8: ...7 Parts layout top side 8 Parts layout bottom side U4B hardware Rev 1 00 8 ...

Page 9: ...9 Schematic U4B hardware Rev 1 00 9 ...

Page 10: ...gh power mode Clk0 and Clk1 are driven at the operating frequency in anti phase 180 degree phase difference The power output into a 50 ohm load across RF_1 and RF_2 is found to be approximately 27mW If Clk0 and Clk1 are connected to opposing legs of a dipole antenna the power output can be conveniently controlled by BASIC commands set to low or high power mode There is no Low Pass Filter in the U4...

Page 11: ...ected battery still has charge The maximum rated input voltage of the RT9013 3 3 is 6 0V absolute maximum rating and recommended maximum operating voltage 5 5V Care must therefore be taken not to use so many solar cells that 6 0 is exceeded Remember that solar panels get BETTER as they get colder In full sunshine at altitude 55C temperatures can increase voltages and currents by up to 20 The U4B c...

Page 12: ... The GPS antenna can be made of simple 28 0 3mm enameled wire a 1 4 wave at 1575Mhz is about 45mm The feedline consists of 1 inch of twisted wire about 6 turns works well The above is just an example of a minimal flight tracking system You can add your own sensors and complexity as you see fit There are a lot more practical tips about flight system preparation and launch in the FDIM 2021 Conferenc...

Page 13: ...al also explains how to update the U4B firmware using a USB connection to a PC and how to set up tracking on the QRP Labs website For updates and tips relating to this kit please visit the QRP Labs QDX kit page http qrp labs com u4b For any questions regarding the assembly and operation of this kit please join the QRP Labs group see http qrp labs com group for details 13 Document Revision History ...

Reviews: