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TTP229 Capacitive-Sensitive Keyboard? — Parallax Forums

TTP229 Capacitive-Sensitive Keyboard?

Has anyone had success connecting a TTP229 capacitive-touch 4x4 keyboard to a Prop-1 chip? I have the TTP229 data sheet and have tried all clocking arrangements for the serial I/O with the chip, but never get any data. I have a logic analyzer that shows no data during the 16 pulses from the Prop-1. The TTP229 board might be useful in a middle-school class, but not unless I can get some software to work. Any help greatly appreciated. Thanks. --Jon


  • Try this one, works with most sticky back amazon arduino keypads, use pins 0- thru 7, If you change pins you have to modify both objects. Attach connector in the correct direction

  • The pad with the IC, is I2C

  • Try out the Basic I2C, If you don't have it already. And write one, there are a few out there you could modify

  • I forgot to mention the B version vs. the L version.

  • PropGuy2PropGuy2 Posts: 329
    edited 2021-06-02 01:05

    A good keypad / board is hard to find, and everyone needs one, or two. If anyone can get a 4x4 or 4x5 capacitive touch keypad to work Reliably and without Glitches, with over-voltage protection and ferrite beads for RF immunity, I could manufacture 100's or 1000's at a good price and sell all of them.

  • I have it working with the BS2, checkout my post under Basic Stamp

  • Thank you all for your comments and suggestions. I did get soft ware working on an Arduino and on a BBC Micro:Bit. Next up is a QuickStart board. The trick is to set the proper timing of the pulses--a delay of 10 microsec does the job--between each logic transition; that is, 0-->1 and 1-->0 on the clock signal from the computer to the keyboard. Use a delay of 3 millisec between successive bursts of 16 clock pulses so the TTP229 can reset itself. If you try to run scans faster than that you will not get good data. --Jon

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