Months ago SparkFun mentioned that they were working on something similar to the Bus Pirate. We asked them to please consider using the Bus Pirate design because it already has a bunch of features, and it’s in the public domain.
Today we received a prototype of the SparkFun Bus Pirate. SparkFun is the fourth company to sell Bus Pirate hardware, a group that already includes an eBay seller, Fundamental Logic, and Seeed Studio.You might call this the Arduino-fication of the Bus Pirate.
It’s awesome that the Bus Pirate is becoming a popular, widely available prototyping tool. Hopefully SparkFun’s exposure gives a lot more people the chance to use one. Of course, we’d prefer you buy a Bus Pirate at Seeed Studio because each sale directly funds the development of this open source project.
We give our impressions of the SparkFun hardware after the break.
SparkFun started with the BPv3 design, and shrunk the passive components to 0402. This is probably their stock size, the way we use 0805. The Bus Pirate is intended as a hackable engineering tool, the 0402 parts make it more difficult to mod or repair by hand, but that won’t matter to most users.
The 0402 size components opened up a bunch of extra board space. SparkFun added a second USB status LED so that both RX and TX status are displayed. They were also able to move the IO header to the corner, and fit a shrouded connector.
The ICSP header to the PIC is unpopulated. We added our own connector between the PGC and PGD pins in order to trigger the bootloader for firmware upgrades.
SparkFun removed the ferrite bead that filters the USB power supply. They also replaced the 10uF tantalum capacitors on the voltage regulator outputs with ~1uF ceramics. We prefer to include the ferrite bead, but we may follow their lead and reduce the output capacitance on future designs that use MIC5205 regulators.
We had seen the schematics for this Bus Pirate prior to receiving the hardware. VR2, the 3.3volt regulator for PIC, was listed as a 5volt part. The PIC24FJ64GA002 is a 3.3volt PIC, 5volts will eventually ruin the chip. We reported the error, but noticed that they included the 5volt regulator on this prototype. We’re not sure if this is just an engineering sample, or if they had actually manufactured some Bus Pirates with this defect. Update: yes, some shipped, but it has been corrected.
After we hot-aired off the 5volt regulator and replaced it with the correct 3.3volt regulator, the PIC still seems to work. The Bus Pirate passed a self-test without errors.
The Bus Pirate developers don’t get a cut of the SparkFun Bus Pirate sales, but we’re proud our hardware is featured at another site. SparkFun is a great company with a reputation for working with open source hardware.
If you want to support the development of the Bus Pirate, and new features like the AVR STK500v2 programmer clone and the PIC programmer firmware currently in development, please consider buying a Bus Pirate at Seeed Studio.
Each Bus Pirate purchased at Seeed Studio funds the development of this open source project, the bounties placed on new features, and the staff who answer questions in the forum. If you order one from SparkFun, that’s great too!