The Most Geeky Business Card: Runs Linux for Under $3

This Linux-running business card is crafted by embedded systems engineer George Hilliard. The entire card is the size of a credit card, ultra-thin, practical, and costs less than $3.

To create such a card, not only a certain level of theoretical knowledge is needed, but the components must also be inexpensive, so you won’t feel bad about giving them away. The processor is the key to keeping costs low. After extensive comparison and research, George chose the Allwinner F1C100s chip for this card, a compact and cost-effective chip that provides both RAM and CPU in a single package, greatly simplifying the overall design and construction of the card.

Many geek friends have made various interesting creative business cards, including USB business cards, cards with flashlights, and even cards with radio transmission functions, but there has yet to be a card that can run Linux. As a seasoned geek, George made one himself:

This is a complete and the smallest ARM architecture computer, running a custom Linux firmware built with Buildroot.

The card features George’s name, title, email, and other regular information, with a USB port on one corner. When this card is plugged into a computer, it boots up in 6 seconds. With a root filesystem that only requires 2.4 MB, the environment running on this PCB is incredibly minimal.

This card, costing less than $3, already has so many functions, no wonder George’s article garnered over 2000 likes on Hacker News in just one day. Now, let’s see how he did it.

As an engineer, George thoroughly enjoys designing and making this creative business card by hand, but finding sufficiently cheap components is indeed a hassle.

After some research, George chose a cost-effective chip from Allwinner Technology—F1C100s. This chip has been optimized for cost while integrating RAM and CPU, fully meeting functional requirements. This chip can be purchased on Taobao, while other components were sourced from LCSC.

George used JLC to create the PCB, spending only $8 for 10 circuit boards, with a matte black finish that feels good and is reasonably priced.

There were a few small issues during the first PCB production: first, the USB port was not long enough, making it difficult to connect stably with many USB interfaces; second, the chip pins were incorrect, which George adjusted manually.

George manually soldered these small-sized components with solder. Of course, the materials and components used are lead-free and harmless, making it perfectly fine to hand out as business cards.

Here’s the complete material cost:

Of course, George also noted that many costs are unquantifiable, such as shipping and trial-and-error costs, etc. But for a board that can run Linux, a cost of $3 is already very low.

Due to specifications and cost, this card lacks networking capabilities, and the I/O ports are limited, so it cannot run any heavyweight software. However, it does boot up in 6 seconds, and George managed to load the MicroPython interpreter, as well as the classic Unix maze exploration game Rogue and the number game 2048.

This card also stores George’s resume and some photos, as it is still a business card. All users can connect it to a computer via the USB port and log in to the root account through a virtual serial interface to access the system programs on the card.

In the process of making the PCB business card, George used the F1C100s chip and ran the mainstream Linux version 5.2 on it. Finally, George uploaded the schematic for the PCB business card and open-sourced all the code on GitHub.

PCB business card schematic

Source code address:

https://github.com/thirtythreeforty/businesscard-linux

In the original article, George shared detailed operational steps, providing more technical details for interested geek friends. I believe that with all the source code and step-sharing he provided, you too can create such a unique personal business card.

The Allwinner F1C100s integrates leading technologies for HD video decoding, high integration, and low power consumption, suitable for various multimedia audio and video devices. The F1C100s uses an ARM9 CPU, featuring excellent system integration capabilities, rich interfaces, and supporting low-power applications and operating systems like Melis and Linux, greatly enhancing development convenience.

F1C100s official introduction:

http://www.allwinnertech.com/index.php?c=product&a=index&id=73

F1C100s Brief:

http://www.allwinnertech.com/uploads/pdf/20181218155101eb.pdf