Problems with ST touch library

fantery

Problems with ST touch library [Copy link]

STM8S103K uses ST touch library. The problem is that when the product load is small, the key works normally. When the load increases, the key sensitivity gradually decreases. Sometimes some keys will be marked as ERROR.

The main reason is that when the load increases, the key sensitivity also "gradually" decreases.

Have you encountered similar problems? How did you solve it?
Thank you!

zhangq

What does "load" mean?

How much does the load increase? Is there a specific value?

urmysuperstar

                                 Will the increased load affect the sensitivity of the buttons? No, the increased load should only increase the current.

qihaijun

The product has 2 loads, one is a DC12V/5W light, the other is a DC12V/3W fan

laofuzi

                                 I also think that the increase in load should only increase the current

haxinglong

                                 Is it introducing interference?

zyyu

                                 The load is not very large

inonme

2# The perfume city

product has 2 loads, one is a DC12V/5W light, the other is a DC12V/3W fan

Will the increase in load have any impact on the power supply? For example, voltage drop, voltage jitter, or fan rotation causing interference on VDD or VSS? These factors will affect the operation of the touch library.

ydyzz

                                 The anti-interference effect of the ST touch library is really not very good. I rewrote it myself and the effect is not bad. I continue to improve it. It is not as widely applicable as the ST touch library, that is, customized

hecf034

There has been some progress on this issue:

1. After the load is turned on, the MCU power supply has a glitch of about 50mv, and the use of variable frequency power supply has a glitch of more than 100mv. Whenever there is a power fluctuation, the touch sensitivity will have problems.

2. We used PB4 as a key pin and PB5 as a shielding pin. These two pins are special and are not suitable for key-related applications.

After using it, the PB4 button is often set to ERROR, and the shielding effect of the PB port is not ideal. Since the key often enters the ERROR state, the initial is re-made. Although it can be used, the effect is not ideal, and it is even worse under power interference.

Now the I/O port has been modified, and it feels much better. I will share with you if there is progress.

lilixia

                                 It is said that ST's RC mode touch library has relatively high power requirements, which is consistent with what LS said.

rcsun

                                 The person above said that the software's anti-interference function is not good enough?

linsijing

                                 No satisfactory answer to close the thread? ...

baiyang8361

It is said that ST's RC mode touch library has relatively high power requirements, which is consistent with what LS said.

In addition, since this library will disable interrupts when measuring charge and discharge time, it is not suitable for applications that require high interrupt response, such as simulating SIP interfaces.

lidj

In addition, since this library will disable interrupts when measuring charge and discharge time, it is not suitable for applications that require high interrupt response, such as simulating SIP interfaces.

The RC library will turn off interrupts when measuring charge and discharge time. There is no way to solve this problem. Only by turning off interrupts can the charge and discharge time be accurately measured. To solve this problem, you can consider using the STM8L touch library, which is said to be able to overcome this problem.