AN3404

Low power mode management by the STM8TL5x STMTouch Library

Doc ID 018847 Rev 3

25/30

Code example 1

// Configure the Zone

TSL_acq_ZoneConfig(&MyZone, 0);

// Set the AL bit to exit from WFI mode only on PXS interrupt

CFG->GCR |= (uint8_t)CFG_GCR_AL;

// Start Bank acquisition

TSL_acq_BankStartAcq();

wfi();

// Process Objects

TSL_obj_GroupProcess(&MyObjGroup);

// DxS processing

TSL_dxs_FirstObj(&MyObjGroup);

With MyZone being declared as followed:

TSL_Zone_T MyZone = {MyBankSorting, 0, TSLPRM_TOTAL_BANKS};

And MyBankSorting as followed:

TSL_tIndex_T MyBankSorting[TSLPRM_TOTAL_BANKS] = {0, 1, 2, 3};

MyBankSorting is a simple array of index referring to an acquisition bank number.

The second element of MyZone is the index to an element in MyBankSorting used as the

first bank to be acquired.

The third element of MyZone is the number of banks belonging to this Zone.

In this simple example, all the banks are defined in MyZone and sorted from the first to the

last.

User can imagine to declare many zones from a single bank sorting table:

TSL_Zone_T MyZone = {MyBankSorting, 0, TSLPRM_TOTAL_BANKS};

TSL_Zone_T MyZone1 = {MyBankSorting, 1, 3};

TSL_Zone_T MyZone2 = {MyBankSorting, 3, 2};

And MyBankSorting as followed:

TSL_tIndex_T MyBankSorting[TSLPRM_TOTAL_BANKS] = { 0, 1, 2, 3, 6, 5, 4};

With such declaration, the acquisition on MyZone will acquire all acquisition banks, while

MyZone1 acquires only bank 1, 2, 3 and MyZone2 acquires only bank 3 and 6.

7.2.2

Very low power management with proximity detection

This example shows how to manage a proximity detection by scanning the key each 512

ms. This is done by alternating Active-halt mode with the AWU and Active-halt mode with

ProxSense. Once a proximity is detected, a scan of the touch keys is performed. This last