Some info The app works on the LG Optimus V but it does not work on the Atrix 4G it keeps acting like it detects card data so I assume its reading from the second microphone. For the users asking New vs Old it does not work on the new readers. However cracking open the New reader and desoldering the board and wires then adding a 100ohm 1/8watt resistor inline seems to work well.
Droid X2 Did not work on a Droid X2 version 2.3.5. Get the bad read message. Tried various credit cards. Square worked just fine, even on a card that I have trouble with at the store. It would be nice to know what it thinks it got.
Red circle stays red, will not read cards, using a homemade reader, an actual credit card reader head direct wired to the mic terminals of the TRRS plug. May work with the square reader, but I don't know how to tell the old non encrypted one from the new one. Tried tweaking settings, still no luck. Update: I now have a generic reader, and it reads cards 2 out of 5 times with the app.
Didn't work at all for me on Acer A500 using various cards the SquareUp app can read easily. Every swipe failed with a, "bad read, try again" error.
It doesn't work Moto G 1st and 2do generation. Always 'Bad read'. I tried with different settings without any result.
Works with Galaxy S3 This worked with my Galaxy S3 (model i747). I used the original Square credit card reader and was able to read Visa, Master Card, driver's license, and several other magnetic stripe cards. By creating a shim, I was able to read each track on the card and pull data such as card number, expiration date, name, and address. I set the sample rate to 22050, threshold level to 50%, and silence level to 500. If you receive the "bad read" error, try applying different pressure to the card as you swipe or swipe back and forth. The Square readers are temperamental. Functionality is perfect but I'd like to see some improvements to the user interface.
Removed a few debug statements that might leak info through logs, attempt to fix occasional NullPointer crash on Square dongle insert/remove.