old phone dialer :-3D contacts and dialer keypads old phone dialer :-Black dialer and contacts list old phone dialer :-Blue contact dialer style old phone dialer :-Classic wooden style old phone dialer :-Black style keyboard old phone dialer :-Slick and smooth dialer rotation old phone dialer :-Unique and attractive retro phone dialers Real sound effects change with your finger speed The theme of the old phone will bring something retro and edgy to your phone dial pad. Change your dialer theme quickly and easily with this amazing old phone dialer. You can do that with the help of our old phone dialer application. If you like the old school style of Old Rotary Phone Dialer but you found it is too long to use it permanently you can enable the quick dial mode to combine the best of the old school style with the best of the 21st century.īring you and your phone back to the 20th century with Old Phone Rotary Dialer Keypad!!!It's time to turn your regular phone dialer keypad into a colorful old phone keypad. Launch Old Phone Dialer, turn the rotary and dial to number of your contacts and friends. Dial your desired numbers using old rotary dialer with classic old ring tunes while dialing through old phone dialer keyboard.įlash back to the 50's with this authentic old phone dialer. It's just 12 buttons arranged in a row/column fashion.Old Phone Dialer Keypad with rotary keyboard enables you to dial phone number using old fashioned mobile phones. There is no special metals that are vibrating. I cannot come with any explanation on what 'fried' your Arduino, whatever that means, but as long as the phone line is disconnected from the Arduino i see no problems. What Paul is talking about is the very first DTMF-phones that used rather archaic circuits to make the tones - that's not what is in your phone. To use it you need to remove all connections to the telephone's own circuit to use it. Your keypad is a simple one with rows and columns. The Wikipedia page you sent said: I think this is how my keypad works, the buttons themselves work as a wedge that pushes two pieces of metal strips to two contacts - one contact is connected to all the buttons in a row and the other to all the buttons in a column, this made me think that it would be as simple as using the Keypad.H library. Do you mean to say that when I push a button, the metal itself vibrates in a certain frequency, thus creating the right tone? I hope you can help me solve this problem as I really wouldn’t like to mistreat another Arduino I tried to be as precise as possible in describing what happens, if there’s any more necessary info missing please let me know.ĭang. Or did I just make the mistake of not adding the necessary protection to my Arduino’s inputs? It seems I could’ve had to add additional resistors to the rows or columns of the matrix (something I hadn’t done at first) to limit the current, but as there can be found several YouTube videos of people succesfully hooking up matrix keypads directly to an Arduino, I didn’t think it would be necessary.Ī different possible explanation could be found in the keypad itself - although I isolated the pins on the phone for the rows and columns from the rest of the original phone circuit (so if I press a key, the only two things making a connection should be the corresponding row and column pins), I still measure a minimal resistance of 170 ohms and a maximal resistance of 605 ohms between a row and a column if the corresponding key is pressed (so when it should short or have a resistance of nearly zero).Ĭould it be that the original circuit used different resistances by using different alloys in the keypad to let an analog input determine which key was pressed, or maybe even to directly produce the corresponding DTMF frequency?Īnd could it be that the additional unsuspected resistance in the circuit messed up my readings of the buttons pressed? To this point I’m still completely baffled to what caused this unfortunate situation and I’ve been searching and searching for a possible answer.

I’ve found the Keypad.H library and was using it to make sense of the keypad’s input, but when I connected all the wires to the phone’s keypad my output wasn’t as expected - and I even ended up frying one of my Nanos…!

I’m working on a project where I’m reusing an old DTMF phone with a 3x4 keypad to use in combination with an Arduino Nano.

Old phone keypad