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Product WIG-10216 | about 5 days ago

In a blatant attempt to get readers to my blog, I direct your attention to here . The firmware is now more than halfway done, it actually works. Go to this blog entry, get the links to the new firmware there. Use the bootloader tutorial to find out how to get the USB bootloader onto your Logomatic.

Sparkfun guys: You are welcome to examine this code, and if it meets your approval, use it on future production runs of the Logomatic.

Product RTL-09876 | about 8 months ago

Found it again – on a comment by another customer:
Battery protector – DW01
This says that the overdischarge protection kicks in at 2.4 plus or minus 0.1V, and reactivates once the battery is charged up to 3.0V.

Product RTL-09876 | about 8 months ago

Unfortunately I don’t have the part number for the battery protection circuit any more. Caution: doing this may void your warranty, but thats what Sparkfun customers do anyway, right? You can carefully peel back the yellow tape, then the masking tape underneath, to reveal a small circuit board with the battery soldered to one pair of terminals and the red and black wires to the other. There is one (or maybe two, I don’t remember now) chips on that board, in addition to the various passive components. I was able to read the part numbers and type them into Google. One of the hits was for a LiPo control circuit.
If you are careful, you can re-wrap the tape and keep using the battery with no trouble afterwards. Just don’t flex the metal tabs connecting the battery and board too much.

Product RTL-09876 | about 8 months ago

I opened up the yellow tape on one of my batteries to try and find the answer to this. The one I opened up was a 1100mAh from Sparkfun. I presume all the other sizes of batteries come from the same manufacturer. There is a battery protection circuit on this battery, and one of its functions is to protect against overdischarge. If I recall correctly, it cuts out when the battery voltage gets down to 2.5V, and re-enables when the voltage gets back above 2.75V. These are lower numbers than I have heard (around 3V minimum) but I have let these things discharge with no extra protection other than what’s under the yellow tape, with no explosions, no physical changes to the battery at all (heating, bulging, etc) and no apparent loss of life. I have yet to need to withdraw a battery from service due to overdischarge or any other reason, and some of my batteries are two years old.

Product SEN-10530 | about 10 months ago

Has anyone had any capacitor problems like with the early HMC5843 boards? Did Sparkfun do anything special with the caps on these ones, or are they ordinary garden-variety caps?

News - Set Your Project Free | last year

You seem to be selling day 1 and day 2 separately. Both are listed as coming with a bunch of hardware, including 2 xbees. How does that work? If I buy both days, do I get 4 xbees?

News - Friday New Product Post | about a year ago

Open that box up and Free the Kittenz!

News - Your Final AVC Reminder | about a year ago

I didn’t even know I had a logo, but I like it. USS Discovery. “I’m sorry Dave, I’m afraid I can’t do that.” You know that’s going on the vehicle now.

Product PRT-10300 | about a year ago

Nitpick: Check the units in “500mA per hour”. I am pretty sure you mean 500mA, or 500mAh/h, which is equivalent.

Product COM-00315 | about a year ago

Is there a way to use one of these and have a motor go forward, reverse, or coast? Most of the examples I have seen on the web only do forward, reverse, and brake. I need coast, not brake.