Dings and Dents
Updated 1 September 2012 to include the XBee Explorer Dongle
Updated 2 September 2012 to include the Bluetooth Mate Silver
I do a lot of my electronic parts shopping at Sparkfun and one of the categories in their catalog is what they refer to as Dings and Dents. These are what others would call production scrap, boards that for some reason didn’t work out and aren’t worth the time and cost to debug. Rather than throw them out, Sparkfun sells them “as is” for a few dollars apiece. Its a good deal since it cuts down on electronic waste and if you’re good with a soldering iron you can salvage some good parts or even repair them.
Just today I received a few of these boards (there’s no ordering particular ones, you just get what you get) and thought it would be interesting to keep track of my experience with them. Out of the boards received, what’s salvageable? What’s repairable? And most important, what’s my return on investment?
In this particular shipment I ordered 10 boards and received:
- 1 FTDI Basic
- 2 IOIO boards
- 1 Arduino Pro
- 1 BigEasyDriver
- 2 XBee Explorer USB
- 1 XBee Explorer Dongle
- 1 Bluetooth Mate Silver
- 1 Nordic Fob
Total cost, including shipping, was ~$50.
And so, in no particular order…
The BigEasyDriver is a stepper motor driver board for bi-polar stepper motors. I’m not currently doing any robotics so for now this one is set aside.
- Cost – $5.00
- Worth – $0.00
The FTDI Basic is a simple breakout board for the FTDI FT232RL USB to serial IC. Sparkfun has two versions, one for 3.3V, the other for 5V. The boards for each version are almost identical. The difference between them is a jumper on the back. Depending upon which board you want (3.3V or 5V) you short either the left hand or right hand pair.
On this particular board the jumpers for 3.3V were shorted via a board trace, indicating it is the 3.3V version. However, there was also a solder blob shorting the 5V jumpers. I removed the solder blob and plugged the board into a USB port. The computer recognized the board, loaded the drivers, and proceeded to work normally.
- Cost – $5.00
- Worth – $14.95
XBee Explorer USB – Module 1
The XBee Explorer USB is a USB to serial base unit for XBee units. It consists of an FT232RL with headers so you have access to the XBee serial and programming pins. I don’t have any XBee modules but like the idea of an FT232 board that can be used with jumpers to connect to a circuit under test.
When plugged into a USB port, Windows identified the first module as an unrecognized USB device. I pulled it and verified voltage levels on the chip, then started looking at the board schematic and checking traces.
Within a few minutes I found a short between the D+ and D- lines on the USB connector. After reflowing the solder for these pins, Windows recognized the device, loaded the drivers, and it worked normally.
- Cost – $3.00
- Worth – $24.95
XBee Explorer Dongle
The XBee Explorer Dongle is the same thing as the XBee Explorer USB but with a USB connector mounted on the board so it can be plugged directly into the USB socket. I don’t know why this was included in Dings and Dents because it was recognized and functioned as a USB to serial converter as soon as it was plugged in. There may be some issues related to the data lines that I can’t test right now but until proven otherwise I’m going to call this one a win.
- Cost – $3.00
- Worth $24.95
Bluetooth Mate Silver
The Bluetooth Mate Silver is a bluetooth modem designed for use with the Arduino Pro. Like the XBee Explorer Dongle, I don’t know why this was included in Dings and Dents because as soon as I powered it up it connected to my computer, showing up as a Bluetooth serial connection. The only hiccup I ran into was when I was prompted for a pairing code the first time I tried to establish a connection but that was easily remedied looking at the comments on the Sparkfun site (the code is 1234).
- Cost – $3.00
- Worth – -$39.95
At this point I’ve checked out five boards, four of which were either easily repairable or in working order to begin with. The list price for these four boards is ~$105 so even if none of the remaining boards work out I’ve made back the original $50 investment.
Keep in mind that Dings and Dents are kind of a crapshoot. You get no choice regarding what you get and it may turn out the next time I do this I get no salvageable boards, but at the very least there will be some good surface mount parts.