hult
Active Member
A low-power barometer and one-channel air temperature sensor with RS-232 interface can be purchased for $17 on ebay:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=110709906816&ssPageName=STRK:MEWNX:IT
It uses a MS5561 10-1100 millibar serial-output pressure sensor and a 20-pin PIC16F690 microcontroller with "nanoWatt" technology, and 10-bit ADC on a 24-pin carrier PCB. It can be configured for pressure and temperature to be read with simple ASCII commands via RS-232.
PCB Schematic here: http://www.sure-electronics.net/download/MB-SM11111_SCH.pdf
PCB Manual here: http://www.sure-electronics.net/download/MB-SM11111_Ver1.0_EN.pdf
The schematic indicates that the PIC programming and clear pins are brought out to a 5-pin header at J2. So one should be able to reprogram the PIC and repurpose the I/O pins within the constaints of the modest on-chip memory -- and asuming competence in PIC programming. I do AVR but not PIC.
PIC: http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en023112
Sensor: http://www.amsys.info/products/ms5561.htm
I purchased it for evaluation as a vacuum leak detector for an underwater (SCUBA diving) camera housing but it would also be very applicable to home automation.
I'll let y'all know what I learn once it arrives.
Hope This Helps ... Marc
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=110709906816&ssPageName=STRK:MEWNX:IT
It uses a MS5561 10-1100 millibar serial-output pressure sensor and a 20-pin PIC16F690 microcontroller with "nanoWatt" technology, and 10-bit ADC on a 24-pin carrier PCB. It can be configured for pressure and temperature to be read with simple ASCII commands via RS-232.
PCB Schematic here: http://www.sure-electronics.net/download/MB-SM11111_SCH.pdf
PCB Manual here: http://www.sure-electronics.net/download/MB-SM11111_Ver1.0_EN.pdf
The schematic indicates that the PIC programming and clear pins are brought out to a 5-pin header at J2. So one should be able to reprogram the PIC and repurpose the I/O pins within the constaints of the modest on-chip memory -- and asuming competence in PIC programming. I do AVR but not PIC.
PIC: http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en023112
Sensor: http://www.amsys.info/products/ms5561.htm
I purchased it for evaluation as a vacuum leak detector for an underwater (SCUBA diving) camera housing but it would also be very applicable to home automation.
I'll let y'all know what I learn once it arrives.
Hope This Helps ... Marc