Component Selection

Speaker Comparison

1. CMT-1209-590T Buzzer

   

   • $1.54/each
   • link to product

   Pros	Cons
   Loud Output (90 dB)	One tone
   Through Hole mount	Fixed resonant frequency
   Simple PWM drive

2. VECO 50CS08FH-1 Speaker

   

   • $0.59/each
   • Link to product

   Pros	Cons
   Low Cost	Pretty Quiet (85dB)
   Low Power Use	limited tone range
   Through hole mount

Choice: Option 1:VECO 50CS08FH-1 Speaker

Rationale: The VECO 50CS08FH-1 provides a easy to integrate solution for the outdoor temprature alert sound syestem. It can be used directly by th e micro controllers PWM signal with a op amp and transitstor. Wit it beinf through hole mount and solid sound with out requiring a dedicated audio driver. The alternative is too quiet for realistic outdoor use.

Op Amp Comparison

1. Microchip MCP6004

   

   • $0.67/each
   • link to product

   Pros	Cons
   has a Dip 14 package	Limited current drive
   Easy for 5V systems	low Bandwith (1 MHz)
   Has Rail to Rail Input and Output

2. Ti LM358

   

   • $0.27/each
   • Link to product

   Pros	Cons
   Really cheap and Available	Only handles 3.5V
   good for low frequency analog systems	Higher offset voltage

Choice: Microchip MCP6004 Rationale: The MCP6004 is made for 5V systems such as our Curisosity Nano. Its consumes low power and comes with the Dip-14 package. The alternitive was better in cost but lacks accepting 5V. The MCP is not complex and will be easy to integrate into our system.