2.8 KiB
2.8 KiB
Goal
Build a handheld device that can be used to test the 8 strand ribbon cables that connect the MRFC522 readers to the RPi breakout board.
To Do
- Design & print ribbon cable tester case bottom half 🔼 ➕ 2024-05-15 ✅ 2024-06-07
- Design & print ribbon cable tester case top half 🔼 ➕ 2024-05-15 ✅ 2024-06-08
- Design & print ribbon cable tester battery door 🔼 ➕ 2024-06-08 ✅ 2024-06-08
- Assembly the unit ➕ 2024-06-10 ✅ 2024-06-10
Parts List
| Part Code | Type | Value | Mfg Code |
|---|---|---|---|
| R1 | Resistor | 68 to 75 KΩ | |
| R2 | Resistor | 1 KΩ | |
| R3 | Resistor | 1 KΩ | |
| R4 | Resistor | 1 KΩ | |
| R5 | Resistor | 10 KΩ | |
| R6 | Resistor | 100 Ω | The ratio of R6:R7 is 1:3.3 (0.30) |
| R7 | Resistor | 330 Ω | |
| C1 | Ceramic Capacitor | 0.01 µF | 104 |
| C2 | Ceramic Capacitor | 10 µF | 106 |
| RV1 | Potentiometer | 100 KΩ | 104 |
| U1 | Integrated Circuit | LM555 | |
| U2 | Integrated Circuit | CD4017 | |
| D1 - D8 | 5mm LED | Red | |
| D9 - D16 | 5mm LED | Green | |
| D17 | 5mm LED | White | |
| J1 - J2 | IDC Socket | 8 pin | |
Build Notes
- Overall current draw is 0.03 A so power is ~0.27W
References
- This is a good tutorial, but there is no capacitor to pin 5 of the LM555 as in all the other articles, which seems wrong.
- LM555 datasheet
- 4017B datasheet
- The best LM555 tutorial. It actually works.