Commodity parts like ceramic capacitors, resistors, LEDs, and discrete transistors cover circuit boards and seemingly overtake the expensive ICs they support. Engineers affectionately refer to these parts as "jelly beans." From hobbyists doing one-off builds up to houses doing full production runs, one challenge for everyone is keeping track of reels of those jelly bean parts. To address this challenge, Great Big Factory is launching a Crowd Supply campaign for an open sourced surface-mount component reel counter called BeanCounter.
"Whether you’re making a few widgets for fun, throwing together badges for a con, or stocking your online shop, you have better ways to spend your time than counting grains of rice." — Great Big Factory
The pocket-sized device measures 25 by 117 millimeters and weighs only 50 grams. While an external 3V supply can power it, most users will appreciate that it also runs from a single CR2032 coin-cell battery. Counting happens with two IR photointerrupters.
The IR sensors count the holes in the tape reel, and then a Microchip ATtiny861V 8-bit microcontroller does a little math to determine the parts count. The count depends on the component pitch, which the user can configure.
BeanCounter can count opaque-style tapes 8 millimeters wide and up to 2 millimeters high. Great Big Factory says this covers 0805 or smaller components for LEDs, passives, and SOT23 packages. The three digits, stylized like 7-segment displays, can count to 999.
Two counting modes cover the two main use models for BeanCounter. First, in inventory mode, BeanCounter polls as fast as possible with a single sensor so that it can count tape or partial reels pulled in one direction.
While in dispense mode, both sensors monitor the direction that tape moves through BeanCounter. This feature is ideal for taking parts off the shelf or kitting them.
BeanCounter's design is open source. The Arduino firmware, EAGLE schematics, and PCB files are available in this GitHub repository.
We reached out to Nick Poole of Great Big Factory to inquire about pricing. Poole said that is one of the details being finalized. However, compared to some of the existing commercial options that are somewhat similar (on paper), BeanCounter will definitely be an affordable alternative. Additionally, there are plans to offer "Shop Packs" with multiple units and other battery options.
Update: the BeanCounter Crowd Supply campaign is now live. The price starts at 75 USD before shipping. (Shipping to the United States is free and 10 USD to the rest of the world.