Bus Pirate IC test PCB

A discussion in the forum led to the creation of a new chip demonstration/test PCB for the Bus Pirate. This board has spaces for several commonly-sampled I2C and 1-Wire devices, and an HD44780 LCD tester:


  • 24LC EEPROM (PTH and SMD)
  • TC74 temperature sensor (PTH)
  • DS1085(L)/DS1077(L) frequency generator (SMD)
  • PCF8563/DS1307 real-time clock (PTH)
  • MCP3021 analog to digital converter (SMD)
  • MCP4725 digital to analog converter (SMD)
  • PCF8574 I/O expander, compatible with Bus Pirate HD44780 LCD tester (PTH)


  • DS2431 EEPROM (PTH)
  • DS1822 temperature sensor (PTH)
  • DS2450 analog to digital converter (SMD)
  • Extra footprints for TO-92 1-wire devices

HD44780 LCDs

  • The PCF8574 is routed to an LCD connector that’s compatible with the Bus Pirate’s LCD library.

Our plan is to make a few the next time we order PCBs, and give them away. We can probably squeeze a few more chips onto the board if you have any requests. Are there any other chips you’d like to see on this board, either from our existing demos or maybe a new device?

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  1. I just finished something else that I was working on today and was going to take a stab at this. Glad to see that you found time to hop on this already.

    lol, i knew someone was going to want the nunchuck connector… ;)

    From eye-balling the PCB image, it doesn’t appear that the headers for the I2C interface and the VOut/AIn are on a 0.1″ grid (but if they are, never mind!). Having any PTHs that you might want to sink down into a 0.1″ solderless breadboard would be (more than) nice. Not that we *have* to learn from Arduino’s mistake(s), but… :)

    I’ve heard that one of the problems that people have with 1-wire is dangling devices off of long wires (that run out to the garage/shed/etc.). So unless the TO-92 PTHs are on a standard header grid/size (like 0.1″ or whatever JST uses), it might be nice to have such a header on the existing TO-92 daisychain. Perhaps even make that header be to an RJ-11 footprint on the board edge.

    HD44780 connector’s great, BTW.

    In my own head, I was (also) thinking of having an SPI section, also separately powered. For instance, for an MSOP-8 LTC1602 (SPI) DAC and the SPI-flavored 23K SRAM, 25AA/CAT25 EEPROMs.
    But I’ll grant that these choices are driven by parts that I already have but hadn’t yet gotten around to frobnicating. If I2C @400MHz is fast enough to do good audio, then SPI may not be necessary/desirable to others.

    Looks like the board may already longer than 10cm though (?). Might you want to keep it to 10cm x 10cm by design to take advantage of “the Seeed special”?

    Looks really good Ian. Have you had anyone put another set of eyes on the sch/brd files yet? If not, I’ll try to take a look at it if you’d like.

  2. Thanks for the suggestions.

    I’ve moved the ADC/DAC pin headers to the edge of the PCB.

    There were some SPI parts on the board, but the combined routing got pretty messy, and the PCB pretty big. There’s also the problem if individual chip select lines. There was a PC keyboard connector too, but it didn’t work out. Maybe in the next revision or on a separate PCB.

  3. Ian,
    congrats on this, looks like a great idea to me, to improve & extend usage of the Bus Pirate. I would love to use it, mainly for I2C & testing HD44780 LCDs, so keep us posted when you get PCBs.
    I’m waiting for my own BPv3, ordered bu the end of November, but still in HK due to HK Post’s overload. Still hoping to get it by Christmas, though :)
    Cheers !

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