BalloonSat Assembly Manual December 2011 S. B. Ellison Electronics Development Group Department of Physics and Astronomy Louisiana State University Baton Rouge, LA Description BalloonSat is a micro-controller based development board, which serves as the platform for learning to use and apply the Parallax BASIC Stamp micro-controller. BalloonSat includes additional memory, an analog-to-digital converter, a real time clock and a prototyping area. BalloonSat can be used as a compact data acquisition system in the laboratory or integrated into a student designed balloon payload where it can serve as the payload flight computer. BalloonSat is programmed with the Parallax, Inc. BASIC Stamp Editor using the PBASIC language. PBASIC is version of the BASIC language enhanced with a number of specialized input/output (I/O) instructions well suited for data collection and control applications. The Stamp Editor runs on a personal computer where user programs are written, edited, and then downloaded to the BASIC Stamp module. Several different versions of the BASIC Stamp are available from Parallax, Inc. BalloonSat uses the BS2P24 module. Background The BalloonSat design evolved from CanSat, a project conceived by Professor Bob Twiggs at Stanford University's Space Science Development Laboratory. The original CanSat included an auxiliary EEPROM memory chip for data storage and a modem (modulator-demodulator) to allow connection to an external radio transmitter and receiver.
The LaACES design for BalloonSat eliminates the modem of CanSat, but provides a number of enhancements including a 4-channel analog-to-digital converter, voltage reference, temperature sensor and 4 on-board LED s for use as visual indicators. CanSat provided pins for connecting external hardware. BalloonSat retains these expansion pins but provides a prototyping area with GND and VCC power buses for use by user provided components or circuits. Theory of operation Operation of BalloonSat is best understood by referring to Figure 1,the BalloonSat Block Diagram and the BalloonSat schematic diagram. Integrated circuit U1 is the Parallax BS2P24 micro-controller module. This module looks somewhat like an integrated circuit but is actually a V IN U3 +5 VDC REGULATOR +5VDC RS-232 Personal Computer DS1 DS2 P7 P6 U1 DS3 DS4 P5 P4 BASIC STAMP BS2P24 I/O Pins P0 P7 I/O Pins P8 P15 Ch 0 Ch 1 U4 P14 P15 P13 U2 EEPROM MEMORY P8 P9 U6 Ch 2 Ch 3 ADC U5 V REF TEMP SENSOR VBATT U7 REAL TIME CLOCK P10 P12 P11 Figure 1.BalloonSat Block Diagram hybrid containing several integrated circuits, transistors and passive components on the 24 pin dual-in-line carrier. This component alone, with a suitable power source and connection to a personal computer running the Parallax software is a self-contained microcomputer. The BASIC Stamp module contains on-chip flash memory for program storage. Once programmed, the BASIC Stamp can be disconnected from the personal computer. The BASIC Stamp begins execution of its downloaded program on power-up. LaACES BalloonSat Assembly 12/12/2011 Page 2 of 17
The major functional subsystems of BalloonSat are depicted in the block diagram. The schematic diagram shows all the components and electrical connections. The BASIC Stamp and other integrated circuits all require a clean, stable +5VDC power source, commonly designated as VCC. BalloonSat will accept an external DC power source of +9 to 15VDC. Diode D1 (in the schematic diagram) is a protective device to prevent damage which would be caused by connecting a power source of the wrong polarity. Voltage regulator U3 maintains a constant +5VDC output under conditions of changing input voltage or amount of current required by BalloonSat. The regulator can supply enough current for all of BalloonSat s on-board components as well as some user supplied circuitry connected to the expansion pins or the prototyping area. You should consult the U3 datasheet and make a careful estimate of the power required by any added electronics. Under some conditions, U3 may run hot. A heat sink could be required to help maintain U3 at a safe temperature. The simplest I/O subsystem consists of LED s DS1 DS4. The individual LED s are controlled by I/O pins P4, P5, P6, P7. The series resistors shown in the schematic limit the current to a safe value. These I/O lines could be used for other purposes but the series resistors R1, R2, R3, R4 and/or the LED s might need to be removed, particularly if these pins are needed as input bits. The values of R1-R4 can be changed if more or less current is desired. The other peripherals, EEPROM, ADC, and RTC communicate with the BASIC Stamp via a synchronous serial interface. The block diagram summarizes which I/O pins are used for each device. The BASIC Stamp always serves as the master device in synchronous serial communication. The master initiates all operations and generates the required serial clock signal. Various protocols have been established in the industry for doing synchronous serial I/O. Some common protocols are the Inter-Integrated Circuit (I 2 C) developed by Phillips Semiconductor, Microwire from National Semiconductor, Serial Peripheral Interface (SPI) created by Motorola and the Dallas Semiconductor OneWire protocol. Component datasheets will usually describe the protocol used in sufficient detail for writing and debugging user programs. Example circuits and programs are often available from the chip manufacturer s databooks or websites. The BASIC Stamp has a flash memory for storing the executable program and a limited amount of RAM (random access memory) for variables and data. The flash memory retains the program even if power is lost. The RAM is volatile; data is lost on power failure. U2, a 24LC64, is an electrically-erasable-programmable-read-only-memory (EEPROM) integrated circuit. EEPROM is non-volatile but can be erased and used again. Most EEPROM s have a limited number of write cycles before it wears out but this is usually on the order of 50,000 writes. It is possible to wear out the EEPROM if a user program runs away and repeatedly writes to the EEPROM chip. Inadvertently placing a write routine in an endless loop is a common programming mistake. Fortunately, the EEPROM chip used in BalloonSat is not expensive. U2 conforms to the I 2 C synchronous serial protocol using I/O pin P8 as the bi-directional data line and P9 as the serial clock. See the 24LC series datasheet for details of using the EEPROM. It is often necessary or desirable to have the current time and/or date available to a BASIC Stamp program. For example, a data logging application may need to save a measurement along with the time/date of the measurement for later analysis. Applications may need to perform operations at specified intervals or times or to log the time and date of an event that occurs. It is possible to LaACES BalloonSat Assembly 12/12/2011 Page 3 of 17
program the BASIC Stamp to perform time keeping using timing loops created in software, but a better approach is to have a dedicated RTC (real time clock) that continually runs regardless of what other tasks the BASIC Stamp may be performing. Usually an RTC will also have provisions for continuing to run even through a power outage. BalloonSat uses a Dallas Semiconductor DS1302 time keeping chip with a backup battery. A CR2032 lithium coin cell is mounted on the BalloonSat board. The current requirements are so small that the backup battery will typically last its shelf life for this type of application. Note that this backup battery only serves the RTC. The other systems of BalloonSat still require the VCC supply for proper operation. The DS1302 uses a simple three wire serial interface. I/O pin P11 is used as a serial clock. I/O pin P10 is the bi-directional data line, and I/O pin P12 is a chip-select for the DS1302. Although BalloonSat has only U7 connected to these I/O pins, the chip select function allows multiple peripherals to share the same clock and data lines as long as only one of the bussed chips has its chip-select line asserted. U7 requires crystal Y1, a 32.768 khz resonator, as the frequency determining element of its internal oscillator. BalloonSat features an 8-bit Analog-to-Digital converter with an on-chip 4-channel input multiplexer. This IC, designated U4, is a National Semiconductor ADC0834. The multiplexer allows up to 4 input voltages to be digitized by a single ADC. An Analog Devices AD780 voltage reference integrated circuit provides a selectable 2.5 or 3.0 volt reference for the ADC. Jumper JMP2 selects the desired reference level. Leaving the jumper removed selects 2.5 V. Placing a shorting jumper at JMP3 connects pin 8 of U5 to GND, selecting 3.0 V as the reference output. The AD780 has an internal temperature transducer providing a 2 mv/ o C output. As shown in the block diagram and schematic, the TEMP output from U5 is amplified by opamp U6. Resistors RV1, R5 and R6 determine the voltage gain of this stage. Variable resistor RV1 can be adjusted by a small screwdriver for fine adjustments. The output from U6 can be connected to Ch3 of the ADC. On the BalloonSat board jumper JMP3 allows selecting either the amplified temperature transducer signal or an external voltage source as the input to Ch3. Pads are provided on the circuit board for connecting inputs to the ADC channels. The safe voltage level for these signals is 0 (GND) up to the reference voltage (2.5 or 3.0). External signal conditioning electronics may be required to interface other levels. The ADC0834 communicates with the BASIC Stamp with the MICROWIRE synchronous serial interface. I/O pin P14 is the serial clock, pin P13 is the data line, and P15 is the chip select. Notice in the schematic that the DI (data in) and DO (data out) are both connected to P13. The BASIC Stamp, under software control, will configure P13 as an input or an output depending upon whether the ADC is being written to or being read. It would also be possible to have separate data in and data out I/O lines but it is frequently necessary to conserve I/O pins, particularly in larger systems. Frequently there is a need to create a custom circuit as part of BalloonSat but without the time and expense of a separate circuit board. The prototyping area provides space for soldering components directly on BalloonSat. Pads are provided for GND and VCC and for the BASIC Stamp I/O lines P0 through P15. It is best to draw the desired circuit and layout a tentative component placement plan prior to actually beginning soldering components to the BalloonSat LaACES BalloonSat Assembly 12/12/2011 Page 4 of 17
board. Components can be unsoldered and removed but there is always the possibility of damaging the circuit board by excessive heat from the soldering iron. Be sure that BalloonSat s power supply has been disconnected before mounting or soldering components in the prototyping area. Be careful not to short connections to GND or VCC. After any modifications, visually inspect the prototyping area before powering up BalloonSat. BalloonSat version 3.0 includes a 26-pin header (P4) for connection to a LaACES developed sensor signal conditioning subsystem. The sensor board supports pressure, temperature and relative humidity sensors. The signals on the 26-pin connector are listed in Table 8. These signals can also be used to interface to custom designed external circuitry for signal conditioning or other applications. Building the BalloonSat The BalloonSat will be constructed and tested in stages. You will perform inspections and tests at the completion of each stage. Should a problem or failure be discovered, it must be corrected before proceeding to the next stage. The stages and the steps in each stage should be performed in sequence. It is good practice to check off each item as you complete it. A bare BalloonSat printed circuit board is shown in Figure 2. Figure 2. BalloonSat Printed Circuit Board (Component side view) LaACES BalloonSat Assembly 12/12/2011 Page 5 of 17
Table 1. BalloonSat Stage 1 Assembly Check off each item as it is completed. JMP1 2-pin male vertical header connector, solder one pin only, then inspect to be sure the assembly is flush against the board and that the pins are vertical. If alignment is correct, solder the remaining pin. J1 U1 Socket only U3 J2 D1 C1 9-pin connector. Carefully guide pins into holes on the printed circuit board. Some pressure may be required to seat the connector flush against the board. Verify alignment of the the pins before soldering. 24-pin integrated circuit socket. Be sure the notch at one end of the socket is oriented to match the part outline on the printed circuit board. Solder only two pins, at diagonal corners of the socket, then inspect to be sure the socket is flush against the board. Solder the remaining pins. Carefully bend the three leads of the IC as shown in the photo. Place the IC on the printed circuit board so that the metal flange is flush against the board, solder one pin. Inspect alignment. Solder remaining two pins. 2-pin power connector (at left in the photo). Before soldering J2, snap on its mating socket (at right in photo) to maintain alignment of the pins during soldering. The shorter pins are inserted through the circuit board. Schottky barrier polarity protection diode, 1N5819, observe orientation of banded end. The band is silver. Be sure to match component outline. Form the leads to 0.4 spacing. Save the clipped leads to be used for test loops. 47 microfarad ( F) electrolytic capacitor, marked with 47uF. This capacitor is polarized.. Observe the polarity markings on the printed circuit board and on the capacitor. C2 0.1 microfarad ( F) monolithic ceramic capacitor, marked 104. Ceramic capacitors are not polarized. C3 0.1 microfarad ( F) monolithic ceramic capacitor, marked 104 C5 0.1 microfarad ( F) monolithic ceramic capacitor, marked 104 C6 0.1 microfarad ( F) monolithic ceramic capacitor, marked 104 C8 0.1 microfarad ( F) monolithic ceramic capacitor, marked 104 C10 0.1 microfarad ( F) monolithic ceramic capacitor, marked 104 C11 0.1 microfarad ( F) monolithic ceramic capacitor, marked 104 C12 0.1 microfarad ( F) monolithic ceramic capacitor, marked 104 C13 0.1 microfarad ( F) monolithic ceramic capacitor, marked 104 C21 0.1 microfarad ( F) monolithic ceramic capacitor, marked 104 LaACES BalloonSat Assembly 12/12/2011 Page 6 of 17
C4 15 microfarad ( F) electrolytic capacitor marked 15 uf. This component is polarized. Observe the polarity markings on the printed circuit board and on the capacitor. C7 C20 RN1 Socket only 15microfarad ( F) electrolytic capacitor marked 15 uf. This component is polarized. Observe the polarity markings on the printed circuit board and on the capacitor. 15 microfarad ( F) electrolytic capacitor marked 15 uf. This component is polarized. Observe the polarity markings on the printed circuit board and on the capacitor. There is no pin 1 on this single inline package (SIP), however the resistor networks to be plugged into the sockets later do have pin 1 s. RN2 Socket only U2 Socket only U5 Socket only U6 Socket only U7 Socket only U4 Socket only 8-pin integrated circuit socket. Be sure the notch at one end of the socket is oriented to match the part outline on the printed circuit board 8-pin integrated circuit socket. Be sure the notch at one end of the socket is oriented to match the part outline on the printed circuit board 8-pin integrated circuit socket. Be sure the notch at one end of the socket is oriented to match the part outline on the printed circuit board 8-pin integrated circuit socket. Be sure the notch at one end of the socket is oriented to match the part outline on the printed circuit board 14-pin integrated circuit socket. Be sure the notch at one end of the socket is oriented to match the part outline on the printed circuit board RV1 500 ohm, side adjust, 25-turn potentiometer. Be sure the component is flush against the printed circuit board. Solder one pin only. Verify alignment then solder the remaining pins. R1 R2 R3 R4 R5 2.2 K ¼W 5% resistor (RED-RED-RED) Resistors R1, R2,R3 and R4 are mounted vertically as shown in the photograph above. 2.2 K ¼W 5% resistor (RED-RED-RED) 2.2 K ¼W 5% resistor (RED-RED-RED) 2.2 K ¼W 5% resistor (RED-RED-RED) 1.2 K ¼W 5% resistor (BROWN-RED-RED) LaACES BalloonSat Assembly 12/12/2011 Page 7 of 17
R6 DS1 DS2 DS3 DS4 JMP2 JMP3 6.2 K ¼W 5% resistor (BLUE-RED-RED) LED LED LED Light emitting diode (LED). The long lead (anode) connects to the square pad on the printed circuit board. The LED should be about a quarter of an inch above the board. Solder one lead only, then inspect to be sure the LED is vertical. If alignment is correct, solder the remaining lead. Refer to the photograph above. 2-pin male vertical header connector. Solder one pin only, then inspect to be sure the assembly is flush against the board and that the pins are vertical. If alignment is correct, solder the remaining pin. 3-pin male vertical header connector. Solder one pin only, then inspect to be sure the assembly is flush against the board and that the pins are vertical. If alignment is correct, solder the remaining two pins. Y1 32.768 khz crystal resonator. BT1 Battery holder for BT1. Be sure the holder is flush against the printed circuit board before soldering. P4 Test point loop VCC 26-pin right angle header. Solder two pins at diagonal corners. Be sure the alignment is correct then solder the remaining pins. Use the wire lead clipped from a diode or resistor to form a small U-shaped loop at the VCC Test loop. Locations are circled in picture at left. Test point loop GND Test point loop GND Use the wire lead clipped from a diode or resistor to form a small U-shaped loop at the GND Test loop. Use the wire lead clipped from a diode or resistor to form a small U-shaped loop at the GND Test loop. This completes the Stage 1 Assembly. LaACES BalloonSat Assembly 12/12/2011 Page 8 of 17
Figure 3. BalloonSat at completion of Stage 1 assembly. Initial tests. Prior to installing the BASIC Stamp micro-controller and the other integrated circuits, you will verify that the power supply section is functioning properly. BalloonSat requires an external power source such as a battery pack or laboratory DC power supply capable of providing 9 to 15 VDC at approximately 100 milliamperes of current. Voltage regulator U3 on the BalloonSat board provides a regulated 5.0 volt output. This power supply level is designated as VCC. Use clip leads or fabricate a power cable to plug into J2 on the BalloonSat board. It is suggested that you color code the leads so that the GND or COMMON lead is BLACK and the + lead is RED. Voltage checks If the laboratory power supply has current limiting, set the current limit to no more than 100 milliamperes and the voltage to 9 volts. If the power supply is not adjustable, any voltage from 9 to 15 VDC is suitable. LaACES BalloonSat Assembly 12/12/2011 Page 9 of 17
Perform the following voltage checks. Successful completion is necessary before installing the BASIC Stamp and integrated circuits. The integrated circuits could be damaged by voltages much higher than 5 volts. Table 2. BalloonSat Initial Voltage Checks RED lead point BLACK lead point Expected Value Your Measured Value + pin of J2 GND Test loop 9V to 15V U1-21 GND Test loop 4.75V to 5.25V U1-23 GND Test loop 0.0V U2-8 GND Test loop 4.75V to 5.25V U4-14 GND Test loop 4.75V to 5.25V U5-2 GND Test loop 4.75V to 5.25V U6-7 GND Test loop 4.75V to 5.25V U7-1 GND Test loop 4.75V to 5.25V OK? Turn off the power supply and disconnect the power cable from J2 when the BalloonSat is not in use. This completes the preliminary testing. If the voltage tests results were not as expected, visually inspect the BalloonSat board for defective or missing solder joints or other construction or wiring errors. If all voltage checks were passed, proceed with final assembly. Final Assembly and Testing of BalloonSat In this phase you will plug in the BASIC Stamp module and the other integrated circuits, resistor networks, configuration jumpers and the real-time-clock back-up battery. After a final visual check of your work, you will apply power and perform a series of voltage checks prior to connecting to a personal computer for operational testing. Table 3. Installation of BASIC Stamp and Integrated Circuits. U1 Install U1, BASIC Stamp BS2P24, in its socket. Carefully remove the IC from its protective anti-static envelope. Identify Pin 1 of U1 s socket and Pin 1 on the IC. Align all 24 pins before gently but firmly pressing U1 into the socket. LaACES BalloonSat Assembly 12/12/2011 Page 10 of 17
RN1 Install resistor network RN1 in its socket. Verify proper orientation of Pin 1. The component will be marked with a dot near Pin 1. Color may vary. RN2 Install resistor network RN2 in its socket. Verify proper orientation of Pin 1. U2 Install integrated circuit U2, 24LC64 EEPROM in its socket. U2 is an 8-pin DIP package. Verify proper orientation of Pin 1. U4 Install integrated circuit U4, ADC0834 analog-to-digital converter, in its socket. U4 is a 14-pin DIP package. Verify correct orientation of Pin 1. U5 U6 U7 BT1 Install integrated circuit U5, AD780 voltage reference, an 8-pin DIP in its socket. Verify correct orientation of Pin 1. Install integrated circuit U6, AD820 opamp an 8-pin DIP, in its socket. Verify correct orientation of Pin 1. Install integrated circuit U7, DS1302 real-time-clock, an 8-pin DIP, in its socket. Verify correct orientation of Pin 1. Install the CR2032 coin cell in its battery holder. The part number and + sign should be UP and visible when the cell is installed correctly. Jumpers are used to configure options on the BalloonSat. Place jumpers as shown in the table below. This is the default configuration and is suitable for most applications of BalloonSat. Table 4. Installation of configuration jumpers. JMP1 Place a shorting jumper (shunt) on the pins of JMP1. JMP2 Place a shorting jumper (shunt) on the pins of JMP2 LaACES BalloonSat Assembly 12/12/2011 Page 11 of 17
JMP3 Place a shorting jumper across pins 2 and 3 of JMP3. This selects Internal Temperature Sensor for ADC channel 3. You are now ready for the final voltage checks of the fully-assembled BalloonSat. Connect to a power supply or battery pack. Perform the following voltage measurements and record the results in the table below. The voltage at U5, pin 6 is the reference voltage generated by U5. The voltage at U5, pin 3 is the BalloonSat internal temperature sensor output. At room temperature it should be about 0.5 volts. BT1 is the backup battery for the real-time-clock. A new CR2032 cell will have a terminal voltage near 3.2 volts. Table 5. BalloonSat Final Voltage Checks RED lead point BLACK lead point Expected Value Your Measured Value VCC Test loop GND Test loop 4.75V to 5.25V U5-6 GND Test loop 3.0V U5-3 GND Test loop About 0.5V Top of BT1 GND Test loop 3.2V OK? Operational Test The final test for the Stage 1 BalloonSat is to verify communication with the BASIC Stamp Editor. Install the Parallax BASIC Stamp Editor on a suitable personal computer. The BASIC Stamp Editor can be downloaded from Parallax, Inc. (www.parallax.com). Version 2.5.2 was current as of 06/30/2011. Connect BalloonSat to the laboratory power supply and adjust for +9 VDC. Connect a standard serial cable from an available serial port on the computer to the DB-9 connector on BalloonSat. For computers without a standard serial port, you can use a USB-toserial adapter. It should be installed and configured according to the instructions accompanying the adapter. LaACES BalloonSat Assembly 12/12/2011 Page 12 of 17
Turn on the power supply, then run the BASIC Stamp Editor. From the Run pull down menu select Identify. The BASIC Stamp Editor for Windows will attempt to establish communications with the BASIC Stamp via any available comm port. You should see a window showing the type of BASIC Stamp detected and its hardware revision number. The version number and comm port number may be different from the example in Figure 4. Figure 4. Screen shot of BASIC Stamp Editor. Programs can be written and downloaded to the BASIC Stamp. Using the BASIC Stamp Editor, type in the simple BASIC program example shown below or you may write your own program. Download and run by clicking the Run icon or from the Run dropdown menu. 'Output a count to the debug screen each second '{$STAMP BS2P} cycles VAR Word 'STAMP directive (specifies a BS2P) 'Variable to store counted cycles. cycles = 0 DEBUG CLS,"BalloonSat starting...",cr Loop: cycles = cycles + 1 PAUSE 1000 DEBUG "Cycle: ", DEC cycles,cr GOTO Loop EXAMPLE PROGRAM Listing 1. Example BASIC program. LaACES BalloonSat Assembly 12/12/2011 Page 13 of 17
You should see BalloonSat writing to the debug window each second with the incremented value of the variable cycles. Figure 5. Screen shot of BASIC Stamp Editor window while running the example program. If your BalloonSat passed all voltage checks and runs the example program, it is ready for use. For further information on the BASIC Stamp hardware and software, refer to the Parallax, Inc. website for additional resources including a detailed reference manual and example programs. The Help function built into the BASIC Stamp Editor is a valuable resource for beginning and advanced programmers alike. LaACES BalloonSat Assembly 12/12/2011 Page 14 of 17
BalloonSat Connectors and Jumpers Table 6. Connector J1, Serial Communications J1 Pin Signal 2 SOUT, serial data out from BASIC Stamp to host PC 3 SIN, serial data in from host PC to BASIC Stamp 4 ATN, connects to PC DTR for programming 5 GND, Common Table 7. Connector J2, Power Input J2 Pin Signal 1 GND, DC Common GND connection, power source 2 Vin, 9 to 15VDC power input Vin from battery or power supply Table 8. Connector P4, Sensor Board Interface P4 Pin Signal 1 BalloonSat VCC 5.0V from BalloonSat voltage regulator 3 P9 I 2 C SCL (BASIC Stamp P9) 5 P8 I 2 C SDA (BASIC Stamp P8) 7 P3 BASIC Stamp P3 9 P2 BASIC Stamp P2 11 P1 BASIC Stamp P1 13 P0 BASIC Stamp P0 15 ADC3 Analog input to ADC channel 3 17 ADC2 Analog input to ADC channel 2 19 ADC1 Analog input to ADC channel 1 21 ADC0 Analog input to ADC channel 0 23 BalloonSat VREF 2.5V or 3.0V Vref 25 BalloonSat VCC 5.0V from BalloonSat voltage regulator Note: All P4 even numbered pins (2 through 26) are GND Table 9. Jumper JMP1 JMP1 State Function Jumper Inserted Connect ATN line from Stamp to J1 Normal Stamp Editor connection Jumper Removed ATN line disconnected from J1 Terminal emulator, e.g. TERM232 Table 10. Jumper JMP2 JMP2 State Function Jumper Inserted Set BalloonSat Vref = 3.0V Jumper Removed Set BalloonSat Vref = 2.5V Table 11. Jumper JMP3 JMP2 State Function Jumper pin 1 to 2 Select external source for ADC3 Jumper pin 2 to 3 Select internal temperature sensor for ADC3 LaACES BalloonSat Assembly 12/12/2011 Page 15 of 17
Table 12. BalloonSat Bill of Materials. BalloonSat Bill of Materials Quantity Part ID Description Semiconductors 1 D1 1N5819 schottky diode, axial leads 4 DS1-DS4 LED, Red wate clear,round 3mm T-1, 0.1in lead spacing 1 U1 BASIC Stamp BS2P24, DIP-24, 0.6in. Spacing 1 U2 24LC64 EEPROM 64K-bit, DIP-8 1 U3 LM7805 Positive 5Volt Regulator, TO-220 1 U4 ADC0834 4-channel ADC, DIP-14 (alternate p/n TLC0834) 1 U5 AD780 voltage reference, DIP-8 1 U6 AD820 single operational amplifier, DIP-8 1 U7 DS1302N real-time-clock, DIP-8 Other Electronics 1 BT1 CR2032 Lithium coin cell, 3V, 20mm 1 Y1 Crystal, 32.768 khz, fundamental, 12.5 pf, radial lead Resistors 4 R1,R2,R3,R4 2.2K 1/4 W 5% RED-RED-RED 1 R5 1.2K 1/4 W 5% BROWN-RED-RED 1 R6 6.2K 1/4 W 5% BLUE-RED-RED 2 RN1,RN2 10K Resister Network, SIP-10 1 RV1 500 ohm top adjust, 20-turn potentiometer, 0.1" LS in-line, Bourns 3299 Capacitors 1 C1 47 uf, 25 volt electrolytic, radial 2mm LS 10 C2,C3,C5,C6,C8, 0.1 uf, 50 V, Kemet monolithic ceramic, 0.2" LS, marked "104" C10-C13,C21 3 C4,C7,C20 15 uf, 25 V, electrolytic, radial, 0.1" LS Hardware 1 PCB BalloonSat Printed circuit Board, LSU 02/2011 BSAT30 1 holder for BT1 Battery holder for CR2032 coin cell, Tyco 12059-1 1 J1 DB-9F connector, right angle PCB mount 1 J2 2 conductor pin header, 5mm spacing 1 Connector, 2-pin, wire mount (mating connector for J2) 1 P4 Connector, 2 x 13 male pin header, right angle 2 JMP1,JMP2 1 X 2 pin header, 0.1" LS 1 JMP3 1 x 3 pin header, 0.1" LS 3 shunt/jumper Shorting jumper for JMP1,JMP2,JMP3 4 Socket DIP-8 IC socket, 8-pin, 0.3" spacing, machined pin 1 Socket DIP-14 IC socket, 14-pin, 0.3" spacing, machined pin 1 Socket DIP-24 IC socket, 24-pin, 0.6" spacing, machined pin 2 Socket SIP-10 socket, 10-pin, 0.1" pin spacing LaACES BalloonSat Assembly 12/12/2011 Page 16 of 17
Figure 7. BalloonSat Component Placement Diagram (Silk Screen Overlay) Figure 8. BalloonSat Copper Layers (Red = Top Copper; Blue = Bottom Copper) Fig 6. BalloonSat Schematic Diagram LaACES BalloonSat Assembly 12/12/2011 Page 17 of 17