List of Parts

Part Quantity Source Cost/unit
ESP8266 2  https://www.digikey.com/product-detail/en/sparkfun-electronics/WRL-13678/1568-1235-ND/5725944  $6.95
TEPT5700 Phototransistor 1 https://www.digikey.com/product-detail/en/vishay-semiconductor-opto-division/TEPT5700/751-1059-ND/1681193  $1.53
 Microstick 2 https://www.digikey.com/en/product-highlight/m/microchip-technology/microstick-ii-dev-kit $36.70
 Adafruit TFT LCD 1 https://www.digikey.com/products/en?mpart=2478&v=1528  $27.50
LED 3 https://www.digikey.com/product-detail/en/cree-inc/C503B-RAN-CZ0C0AA1/C503B-RAN-CZ0C0AA1-ND/6561758 $0.15
FS5103R Servo 2 https://www.digikey.com/product-detail/en/adafruit-industries-llc/154/1528-1496-ND/5774222 $12
Multipole Ring Magnet 2 https://supermagnetman.com/products/r1050?variant=11410341251 $3 for 3
Hall Effect 2 https://www.digikey.com/product-detail/en/melexis-technologies-nv/US5881LUA-AAA-000-BU/US5881LUA-AAA-000-BU-ND/431876 $1
Voltage Reg 2 https://www.digikey.com/product-detail/en/stmicroelectronics/LD1117V33/497-1491-5-ND/586012 $1
Buttons 4 https://www.digikey.com/product-detail/en/e-switch/PS1023ABLK/EG2001-ND/82862 $1.51
Linear Devices  (2) 1nF Cap, (1) 30uF Cap, (1) 10k Resh, (1) 910k Resh  $0.01
Power Supply 2 https://www.digikey.com/product-detail/en/triad-magnetics/WSU050-2000/237-1385-ND/3094911 $10
Laser Cut Parts Custom N/A
PCB Custom (Milled) N/A
ABS shaft https://www.mcmaster.com/#8587k35/=1a6n8jw $2.50
Screws https://www.mcmaster.com/#91772a115/=1a6nac0 $5.29
Nuts https://www.mcmaster.com/#90480a005/=1a6naow $0.87

The total cost comes out to ~$177.48.  However, our actual cost was much lower, as many parts were sourced locally (including the Microsticks and LCD).  The cost of the custom PCB and laser cut mechanical parts were free for us, but would be ~$10 each in terms of materials if the materials were not stocked already.