TTP229-B

Introduction

The TTP229 is a chip used for touch pads. Typically the TTP229 is used with 8 or 16 keys. Power requirements are 2.4V - 5.5V which makes them ideal to use with ESP Easy, the communication protocol is I2C so essentially only 4 cables are needed for up to 16 keys. Please observe that the sibling module TTP229-B is not I2C compatible and thus not supported by ESP Easy!

Hardware

1st-GPIO -> SCL on the module 
2nd-GPIO -> SDA on the module (sometimes labeled SD0)
2.4-5.5V to module VCC 
GND to module GND

Please observe that you should NOT use default I2C pins since this will jam the I2C communication with the other I2C devices. This is because of the non-standard I2C protocol used by this module.

8 keys vs 16 keys

In order to get the 9-16 keys to work you need to bridge the P1.3 pair (see picture below). The setting will come active on boot of the module. Other settings is also possible but not covered in this guide.

ESP Easy

Use the device tab on the ESP Easy web interface and create a new task by editing one of the available tasks. Select "Keypad - ..." from the drop down box.

If you check "ScanCode" the key number will be reported and not the exponential numbering which is generally used when the module is set to allow multiple inputs simultaneously.

The values that this device reports will be as follows:

Key (ScanCode)	Value (8 key)	Value (16 key)	Extra information
1	257	1
2	514	2
3	1028	4
4	2056	8
5	4112	16
6	8224	32
7	16448	64
8	32896	128
9	-	256
10	-	512
11	-	1024
12	-	2048
13	-	4096
14	-	8192
15	-	16384
16	-	32768