| Item Number/Description | Price (Dec 2011) |
| PIC16F690-I/P-ND | |
| (IC PIC MCU flash 20DIP) | $2.44 |
| X909-ND | |
| ZIT-20.00MX ceramic resonator | $0.60 |
| 609-3291-ND | |
| Conn Header 6POS | $0.44 |
| A404AE-ND | |
| 20 Pin Solder Tail Dip Socket | $1.53 |
| 768-1028-ND | |
| Cable USB to TTL Serial Conv | $20.00 |
| Item Number/Description | Price (Dec 2011) |
| VTT3323LAH | |
| IR Detector: Excelitas Tech | $0.66 |
| Item Number/Description | Price (Dec 2011) |
| JW-140 | |
| 140 Piece Jumper Wire Set for Breadboards | 6.25 |
| PB-840 | |
| Breadboard, 840 Contacts | 7.65 |
We note that it is very important to have the correct IR detector. The one listed above, VTT3323LAH from Excelitas Tech (Perkin-Elmer), works well. The detector must have the following resistance properties: high resistance without laser (around 60000 Ohms), and a low resistance when the laser is shining on it (around 50 Ohms). This change in resistance from 50->60000 Ohms acts as a TTL switch on pin 11. I believe the pin goes from low to high at around 1000 Ohms.