# KS0210 keyestudio RPI TTP229L 16-key Capacitive Touch Keypad

![](media/image-20260113105440627.png)

## 1. Introduction

This keypad is designed for Raspberry Pi and supplies your Pi with 16 keys. It has an I2C communication mode and uses 3.3 V supply voltage with a power indicator.

We provide you with installation package, source codes and a document to help you complete your programs.

## 2. Specification

- Chip: TTP229-LSF
- Supply Voltage: 3.3V
- Interface: I2C

## 3. Shipping List

- keyestudio RPI TTP229L 16-key Capacitive Touch Keypad x1
- M2.5*6MM screw x 6
- M2.5*19MM copper pillar x 3

![](media/image-20260113110040642.png)

## 4. Connection Diagram

Plug it directly into Raspberry Pi to start your works as shown in below figure.

After power-on have about 0.5sec stable-time. During the time do not touch the key pad, and all functions are disabled.

![](media/image-20260113110148684.png)

## 5. Sample Code

**Download Resources :  [Resources](./Resources.7z)**

```c
#include <bcm2835.h>  
#include <stdio.h>
#include <unistd.h>
unsigned char WriteBuf;
unsigned char WriteBuf1;  
unsigned int ReadBuf0;  

int main(int argc, char **argv)  
{  
    if (!bcm2835_init())  
    return 1;  
    bcm2835_i2c_begin();  
    bcm2835_i2c_setSlaveAddress(0x57);  
    bcm2835_i2c_set_baudrate(10000);  
    printf("start..........\n"); 

    while(1)  
    {  
		WriteBuf = 0x00;  
		bcm2835_i2c_write_read_rs(&WriteBuf,2,&WriteBuf1,2);  
		bcm2835_i2c_read (&ReadBuf0,2);        
		printf("TTP229:%d\n",ReadBuf0);
		printf ("\r");
		fflush (stdout);
		bcm2835_delay(100);  
    }   
    bcm2835_i2c_end();  
    bcm2835_close();  
    return 0;  
} 
```

## 6. Program Writing

**1.Installing bcm-2835 Library**

Here is the tutorial for installing bcm-2835 library in Raspberry Pi. To install bcm-2835, first we need to download bcm2835 library.

**Step1:** Now after downloading library, copy it in any folder of your raspberry pi by winSCP(we provide its installation package, but please refer to usage by yourselves).

**Step2:** Now it’s time to extract the library, so open terminal of raspberry pi and go to the folder where you have copied your library and type this command: **tar zxvf bcm2835-1.39.tar.gz**

**Step3:** Now to into library folder, type this command: **cd bcm2835-1.39**

**Step4:** Now, we are ready to install bcm2835 library, so to start installation type this command: **./configure**

**Step5:** then type this command: **make**

**Step6:** then this: **sudo make check**

**Step7:**and finally this: **sudo make install**

Congrats your library is installed. Now use “#include <bcm2835.h>” in your program to use bcm2835 library.

**2.Programming**

Now it's time to write a program. If you need to create a new directory within raspberry pi, you can use the ‘mkdir’ command. So type at your terminal: **mkdir rpi_shield**.

Then copy the file **rpi_TTP229L** provided by us and put it into the directory rpi_shield through winSCP. Next, type this command: c**d rpi_TTP229L** to go inside the rpi_TTP229L folder.

Then type this command: **make** to make an executable file; This means this is the file we run to launch the program as shown in below figure.

To make a new directory, you just need to add the name of the directory after the command, such as 'mkdir new_directory'.

Finally type this: **sudo ./TTP229** to launch the program.

![image-20260113111803668](media/image-20260113111803668.png)

## 7. Result

Touch the keys, and corresponding value is printed on the terminal as shown in below figure.
Use **Ctrl+C** to exit the processing program.

![](media/image-20260113111904816.png)

**sudo ./TTP229** to running program

![](media/image-20260113111919132.png)

Touching different keys to print various value.