RA8875::_initializeFT5206(void) Loop problems?

[GremlinsInGame]

void RA8875::_initializeFT5206(void)
{
	uint8_t i;
	for (i=0x80;i<=0x89;i++){
		_sendRegFT5206(i,_FT5206REgisters[i-0x80]);
	}
	_sendRegFT5206(0x00,0x00);//Device Mode
}

Gives Warnings:
RA8875.cpp: In member function void RA8875::_initializeFT5206()
RA8875.cpp: 5265:43: warning: iteration 9u invokes undefined behavior [-Waggressive-loop-optimizations]
_sendRegFT5206(i,_FT5206REgisters[i-0x80])
RA8875.cpp:5264: note containing loop
for (i=0x80;i<=0x89;i++){

Could this be a problem? And how to solve?

[M-rTom]

What happens if you try something like this? for (i=0;i<=9;i++) _sendRegFT5206(0x80+i,_FT5206REgisters[i]); Tom From: GremlinsInGame [mailto:[email protected]] Sent: Wednesday, October 04, 2017 9:39 PM To: sumotoy/RA8875 Cc: Subscribed Subject: [sumotoy/RA8875] RA8875::_initializeFT5206(void) Loop problems? (#127) void RA8875::_initializeFT5206(void) { uint8_t i; for (i=0x80;i<=0x89;i++){ _sendRegFT5206(i,_FT5206REgisters[i-0x80]); } _sendRegFT5206(0x00,0x00);//Device Mode } Gives Warnings: RA8875.cpp: In member function void RA8875::_initializeFT5206() RA8875.cpp: 5265:43: warning: iteration 9u invokes undefined behavior [-Waggressive-loop-optimizations] _sendRegFT5206(i,_FT5206REgisters[i-0x80]) RA8875.cpp:5264: note containing loop for (i=0x80;i<=0x89;i++){ Could this be a problem? And how to solve? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#127> , or mute the thread <https://github.com/notifications/unsubscribe-auth/AQZWzKbkfr8EjPnwcTTKP55adMwKyryaks5spF1JgaJpZM4PujTS> .Image removed by sender.

[GremlinsInGame]

Thank you for the input. I adjusted my code based on your suggestion and then
I just realized that in RA8875UserSettings.h that the _FT5206REgisters[] Array is getting filled with 9 Values but the For Loop is being iterated 10 times.. i<=9
This is/was stuffing a random memory value into the FT5205 0x89 register.
I imagine this causes problems for people.

Also,
Some of the the values that are in _FT5206REgisters[] don't seem to be correct.
Default Values that are listed in the FT5206 Datasheet seem to work better for me.

[seamaster101]

Hi GremlinsInGame,
I read your post for soem of the values for _FT5206REgisters[]. Below is what i found in RA8875UserSettings.h. Is that what you are referring too?
#include "Wire.h"//include the support for FT5206 static const uint8_t _FT5206REgisters[9] = { 0x16,0x3C,0xE9,0x01,0x01,0xA0,0x0A,0x06,0x28 };

what are the new values that you are using? I did look in the datasheet but wasn't sure what to replace these values with.
can you post the line for the values that you are using?
Thanks!

[GremlinsInGame]

The Values I am using now are:

static const uint8_t _FT5206REgisters[9] = {
0x3C,0x30,0x02,0x5C,0x0A, 0x02,0x00,0x02,0x0C
};

You can find the Default Values and descriptions of the Registers starting on Page 34 of this datasheet.
http://www.buydisplay.com/download/ic/FT5206.pdf

I think the Defaults for the FT5206 are (In Decimal)
//70, 60, 16, 60, 10, 20, 0, 2, 12

[seamaster101]

Thank you!