SquareUp is the most amazing way to process credit cards at craft fairs! I used to have a 'knuckle-buster' which scared the heck out of me every time I used it. It wasn't long after I got my Smartphone that I discovered Square (thanks Jef!) and I promptly dumped the beast. Now I keep my processor in a ring box instead of a suitcase.
If you want to sign up for Square go to https://squareup.com/ . They will send you the device for FREE. If you need it sooner than next week you can buy one cheap at radio Shack and Square will refund you. NO, I don't work for them and NO, I don't get a kickback. And Square isn't JUST for craft fairs. Ya gotta check it out.
Since I already added the appropriate text to each photo I won't be adding any additional verbiage. Besides, I've had 2 glasses of wine and it's past my bedtime. Here ya go...
And if you vend at craft fairs you'll find your sales will pretty much double because no one carries cash anymore. You really need to check this out!