Introduction to my Business Card

After 4 years working in an international IT consulting company, I have decided that now it is time to change my current professional career.

The world of the business software (for banking, insurance, services…) is boring, monotone and it is not  challenging enough for me. I would like to redirect my labor situation toward a field more related with the electronic engineering, which is my real passion.


Unfortunately, if the opportunities to work in electronics were scarce and poor (specially with ASIC or RF design, my two favorites  areas), now with the current economical crisis… finding a job (or even an internship) in this field is almost impossible. Or at least, I had no luck so far even considering that I am open to work anywhere in the world.



First impressions matter

In this hard scenario, the Human Resources recruiters receive hundreds of resumes a day from people competing for the same position.

With this avalanche of CVs is impossible for HR to make a full assessment of each candidate. Therefore, the first filtering criteria that is usually applied is the presentation: If your resume does not cause a good impression to the recruiter from the first moment, you will be automatically discarded, regardless of your qualifications.


Any chance to make your CV stand out from others must be seized. A good cover letter and a good presentation is essential, but do not ensure you that will catch enough attention from the reader.
Is at this point when I had the idea to design my own business cards to attach with my resume or give in interviews.


This card, in order to be “flashy”, had to meet the following requirements:

  • Contain my contact information (Captain Obvious to the rescue!).
  • Convey professionalism.
  • Serve as an example of my engineering skills.
  • Have some use besides being a business card. This way, it would prevent to be throw away at the first opportunity.

At first I thought about making a version of my Open RFID Tag with one side of the PCB printed with my contact details and a firmware preloaded to emulate some RFID tag containing the same contact info.
I discard the idea because  few HR recruiters must have an RFID reader in their offices or homes, so they could hardly see the card working.

At the end I opted to do some kind of USB-device card.



My business card

The result is a card with the size of a credit card (85.6 × 54 mm, although thicker) with two punched corners.
In the center there is a “window” to accommodate the microcontroller soldered bottom-up. Otherwise, If the micro was soldered on the PCB (bottom-down), the card would have been very thick and could not be stored comfortably in a pocket wallet.

The front side has my contact details and  the back side has all the electronic parts soldered.

Front side, with the contact information  (phone number censored in the image)


Back side, with the soldered parts.


The corners can be torn apart, exposing an USB connector that lets you plug the card directly to your computer


Corners torn.


The card plugged to the computer



When the card is connected, the computer recognize it as a mass storage unit and will open automatically (Autorun.inf) my resume, cover letter, portfolio, website or any other document.



The main purpose of the card is to work as an USB memory.

The firmware uses the internal flash of the microcontroller, so the capacity  of the mass storage unit is only 24 KB max. Enough to put a cover letter and resume in HTML.
If more memory is needed, the current PCB and circuitry supports  an external 8-pin SPI (or I2C) flash memory chip (up to 32MB!). Interesting for providing the project documentation or code!

In addition, the microcontroller firmware includes a bootloader that allows you to run small programs stored in the USB drive. These programs add functionalities to the card.

At the moment, the following applications are available:

  • Datalogger:
    Capture digital signals.  Capturing modes (without compression / worst case):

    • 8 channels @ 500KHz
    • 4 channels @ 1MHz
    • 2 channels @ 2MHz
    • 1 channel @ 4MHz.
  • Oscilloscope :
    10 bits of resolution. Capture modes:

    • 4 channels @ 67.5KHz
    • 2 channels @ 125KHz;
    • 1 channel @ 250KHz;


These other applications are under development:

  • USB to RS232, SPI, I2C or CAN adapter (bridge)
  • General purpose I/O port for controlling electronic devices and circuits.


Moreover, all the microcontroller pins are available thanks to a Molex connector (not soldered), so the card can also be used as a trainer board for the PIC 24FJ64GB002. Useful for those who wants to enter into the world of microelectronics and embedded systems.


Clearly, it is not the cheaper business card in the world (about 5 euros/piece for a small batch order), but it is a (relatively) small price for having a card in your pocket that has more CPU power than the computer that led the man to the moon.


Technical specifications

  • 16 bits microcontroller PIC 24FJ64GB002  @ 32 MHz (16 MIPS)
  • 64 KB of Flash and 8KB of RAM. External SPI or I2C memory optional (up to 32MB)
  • Up to 11 digital I/Os available (Four of them tolerant to 5 volts)
  • Up to 4 analog channels.
  • ICSP port for debugging and programming. The 3 pins of the ICSP connector can be also used as GP I/Os.


Applications, source and schematics

Click on the image to download the schematics:



I will release the apps and sources under a GPL (or similar) as soon as I solve some questions regarding to the licensing.
The firmware uses part of the Microchip USB stack implementation, whose source is royalty free but is not licensed under an Open Software License. I need to know the limitations of this license before releasing the code.