Low Power Switch Contact Monitor
Budget: $25 – $50 CAD
CPU Environment: Arm Cortex M4 - Hope RF LORA6601 integrated CPU and LORA transceiver.
Monitor 5 I/O pins - to determine if a switch contact is open or closed (this may be an analog resistance measurement - I will define threshold of open and closed in ohms)
Closed is Good, open is alarm condition
Contacts check 1/15 seconds, or allow a variable set during compile so we can test different values.
Also use A/D to drive an LM84T temperature sensor and measure once per minute (variable so we can play with different time periods of how often we check)
Also - possibly a simple interrrupt if 75C is exceeded
Alarm condition if temperature is over 75C
once per 5 minutes - (this is a 'status ok' message)
When alarm conditions occur (contact open or temperature >75C) alarm message sent.
"pairing" prompt on power up or magnetic gauss sensor to send message for "Pairing" to a receiver.
Message payload is 6bits - we have this defined.
Device sends messages only
1650mAH battery - target 5 years life
Power source 3V non rechargeable lithium battery or Thionyl Chloride
Monitor 5 I/O pins - to determine if a switch contact is open or closed (this may be an analog resistance measurement - I will define threshold of open and closed in ohms)
Closed is Good, open is alarm condition
Contacts check 1/15 seconds, or allow a variable set during compile so we can test different values.
Also use A/D to drive an LM84T temperature sensor and measure once per minute (variable so we can play with different time periods of how often we check)
Also - possibly a simple interrrupt if 75C is exceeded
Alarm condition if temperature is over 75C
once per 5 minutes - (this is a 'status ok' message)
When alarm conditions occur (contact open or temperature >75C) alarm message sent.
"pairing" prompt on power up or magnetic gauss sensor to send message for "Pairing" to a receiver.
Message payload is 6bits - we have this defined.
Device sends messages only
1650mAH battery - target 5 years life
Power source 3V non rechargeable lithium battery or Thionyl Chloride