LSU 09/19/2013BalloonSat Development Board1 The BalloonSat Development Board Programming Unit, Lecture 1

LSU 09/19/2013BalloonSat Development Board2 Background The LaACES BalloonSat Development Board evolved from CanSat, developed by Professor Bob Twiggs at Stanford University’s Space Science Development Laboratory. CanSat was designed to be accommodated within a soda can sized satellite enclosure. CanSat featured a BASIC Stamp micro-controller, an additional memory chip for data storage and a modem for connecting to an external radio transmitter/receiver.

LSU 09/19/2013BalloonSat Development Board3 From CanSat to BalloonSat ACES payloads did not need the modem of CanSat. No on-board analog-to-digital converter for sensors. Expanding CanSat with external electronics was inconvenient. LSU designed add-on prototype board. CanSat

LSU 09/19/2013BalloonSat Development Board4 BalloonSat Requirements LaACES BalloonSat designed to include –BASIC Stamp micro-controller –EEPROM memory for data storage and retrieval –Analog-to-Digital converter –Real Time Clock with provision for battery backup –Prototyping area –Expansion capability –Suitable for laboratory activities, payload applications

LSU 09/19/2013BalloonSat Development Board5 BalloonSat Features BASIC Stamp BS2P24 24LCxx EEPROM Real Time Clock 4 channel ADC V ref for ADC Temperature sensor 4 LED indicators prototyping area expansion connector BalloonSat

LSU 09/19/2013BalloonSat Development Board6 BalloonSat EEPROM Memory 24LCxx series CMOS Serial Electrically Erasable Programmable Read Only Memory (EEPROM) is supported. Synchronous serial interface, I 2 C compatible. The 24LC64 provided is a 64K chip organized as 8 blocks of 1K x 8-bits. Data retention of at least 200 years. Erase/write cycles > 10 5

LSU 09/19/2013BalloonSat Development Board7 BalloonSat Real Time Clock Dallas DS1302 Time keeping IC. Synchronous serial interface. Registers for Year, month, day, hour, minutes, seconds. Includes on-chip 31 x 8 bit RAM for scratchpad data storage. Low power requirements

LSU 09/19/2013BalloonSat Development Board8 Analog-to-Digital Converter BalloonSat includes a 4 channel ADC, ADC0834 –MICROWIRE synchronous serial interface Precision voltage reference AD780 –Selectable 2.50 or 3.00 VDC reference for ADC –On-chip temperature transducer On board operational amplifier for buffering and scaling temperature transducer output. Temperature signal can be connected to ADC channel 3.

LSU 09/19/2013BalloonSat Development Board9 Prototyping on BalloonSat Prototyping area features GND and VCC busses. Pads for BASIC Stamp I/O pins P0 - P15 Pad and bus layout is compatible with DIP IC’s (0.300” wide). GND and VCC testpoints Prototyping Area

LSU 09/19/2013BalloonSat Development Board10 Expanding BalloonSat –BASIC Stamp I/O pins are brought out on expansion connector. –Use of I/O pins must be planned to avoid device contention.

LSU 09/19/2013BalloonSat Development Board11 Flying BalloonSat Flying BalloonSat in a student balloon mission requires some special considerations not encountered on the lab bench. –Battery power required Low temperature and pressure environment Suitable batteries for main power and for RTC backup –Integrity of connections for flight applications, direct soldering of cables may be more reliable than connectors. Jumpers should be soldered or secured in place.

LSU 09/19/2013BalloonSat Development Board12 Activity P1 Identify and inventory parts in the BalloonSat kit. Assemble BalloonSat following instructions in manual. Perform functional tests (It’s all in the manual.)