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Instrumented Football Helmet. Theory of Operation and Hardware Design. PIC 18F45K20 Microcontroller use at least 9 channels of ATD conversion with 2 more used for reference voltage 1 SPI used for SD interfacing 2 TTL pins for RS232 interfacing Operating Voltage: 1.8V to 3.6V 1.6-12 mA.
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Instrumented Football Helmet Theory of Operation and Hardware Design
PIC18F45K20 Microcontroller • use at least 9 channels of ATD conversion with 2 more used for reference voltage • 1 SPI used for SD interfacing • 2 TTL pins for RS232 interfacing • Operating Voltage: 1.8V to 3.6V • 1.6-12 mA OPERATION: Microcontroller
Accelerometers • Freescale MMA1212 and MMA2301 Accelerometers • x-axis and z-axis • Operating voltage: 5 V • Operating Current: 3-6 mA • Analog output between 0.5V and 4.5V • Matchport b/g Wireless Adapter • Operating voltage: 3.3 V • Operating Current: 20-223 mA • Connected to microcontroller via RS232 OPERATION Could not find tri-axis accelerometers available with required g measurement range, so two x-axis and 1 z-axis accelerometers will be paired. The Matchport has an embedded web server and output pins programmable from embedded software interface.
SD Card • Connect through SPI • 4 pin interface • Operating voltage: 3.3 V OPERATION The SD card will be interfaced with SPI using the integrated SPI on the PIC18 microcontroller.
Maxim MAX8856 Battery Recharger • USB or AC input • 3.5-4.2V SYS output • Maxim DS2784 Fuel Gauge • Operating voltage: 2.5-4.6V • Ultralife UBBP01 Lithium Ion Battery • 3.7 V rechargeable • 1800 mAh OPERATION: POWER