SMD solder challenge PCB
So, you got your hands on one of those credit card sized PCBs and are wondering what blinking shenanigans it holds? Well, you came to the right place.
Until CTFv3 starts, you can pass the time with testing your soldering skills while completing this (off the record) soldering challenge. Mhmm, on a second thought though, maybe you will be awarded some extra points in case you post a video of the fully assembled and working PCB (or at least how far you got).
Anyhow, here is the BOM (bill of materials) you need to source in order to start. The use of a reflow oven is not forbidden, but real hacker use their old and prooven soldering iron for this (as was the official rule set for the DC26 soldering challenge).
Orientation of the diodes: The cathode of all diodes is facing the battery / away from the MCU. Check the datasheets of the individual diodes for their anode/cathode markings. Pin 1 of the MCU is in the lower left corner (i.e., furthest away from of the ISP pads and the battery).
Once assembled, you need to flash the MCU with the provided firmware first. Here is the download link for the firmware. Use a regular AVR ISP in order to programm the chip.
Credits schematic & firmware: MakersBox. Go and visit his hackaday.io page for some assembly tips, videos, ...
| Quantity | Component | Component Name |
|---|---|---|
| 1x | U1 | IC MCU 8BIT 8KB FLASH 8SOIC Atmel ATTINY85V-10SUR, https://www.digikey.com/short/3253mp |
| 1x | BAT | HOLDER BATTERY 20MM COIN Linx BAT-HLD-001, https://www.digikey.com/short/3rbvh8 |
| 1x | C1 | CAP CER 0.1UF 50V X7R 1206 KEMET C1206C104K5RAC7867, https://www.digikey.com/short/32vmjq |
| 1x | D0 | LED RED CLEAR 1206 SMD Lite-On LTST-C150KRKT, https://www.digikey.com/short/3253m7 |
| 1x | D1 | LED ORANGE CLEAR 0805 SMD Dialight 5988130107F, https://www.digikey.com/product-detail/en/dialight/5988130107F/350-2040-1-ND/1291344 |
| 1x | D2 | LED YELLOW CLEAR 0603 SMD Lite-On LTST-C191KSKT, https://www.digikey.com/short/3wzzr2 |
| 1x | D3 | LED GREEN CLEAR 0402 SMD SunLED XZVG68W-2, https://www.digikey.com/short/3wzzfm |
| 1x | D4 | LED BLUE CLEAR 0201 SMD Kingbright APG0603PBC-TT-5MAV, https://www.digikey.com/short/3wzzfr |
| 1x | R0 | RES SMD 330 OHM 5% 1/4W 1206 Yageo RC1206JR-07330RL, https://www.digikey.com/short/3253mf |
| 1x | R1 | RES SMD 330 OHM 5% 1/8W 0805 YYageo RC0805JR-07330RL, https://www.digikey.com/short/3wzz2f |
| 1x | R2 | RES SMD 330 OHM 5% 1/10W 0603 Yageo RC0603JR-07330RL, https://www.digikey.com/short/3wzz20 |
| 1x | R3 | RES SMD 330 OHM 5% 1/16W 0402 Yageo RC0402JR-07330RL, https://www.digikey.com/short/3wzzwq |
| 1x | R4 | RES SMD 180 OHM 5% 1/20W 0201 Panasonic ERJ-1GEJ181C, https://www.digikey.com/short/3wzzwz |
Note: Components listed from the digikey catalouge are only examples. Other components matching the criteria will do fine as well. In case you order from digikey, they have free shipping (import duty included) on orders over 50€ netto. Maybe a good thing to pool orders...
