| Title | Description | Cost | Link | Picture |
| Real Time Clocks DS1307 SMD | Real time clock chip DS1307 surface mount, needs oscillator and 2.2k resistors.Value: I²C, 2-Wire Serial | $3.53 | Link |
|
| PCB DS1307 Breakout Board | Breakout board for the DS1307 Real time clock chip. Uses I2C protocol. | $4.5 | Link |
|