8-bit|16-bit parallell ILI9341

You need to change “byte” to “gpio_dev*” to get it compiled.

gpio_dev* xp_port = digitalPinToPort(xp);
gpio_dev* yp_port = digitalPinToPort(yp);
gpio_dev* xm_port = digitalPinToPort(xm);
gpio_dev* ym_port = digitalPinToPort(ym);


There is some progress … I can see some readings but they are unstable and unreliable. And it is not showing a pressure …

I can’t help much other than suggesting to compare your code with the function TouchScreen::pressure(void) from STM32F1/libraries/Touch-Screen-Library_STM/TouchScreen_STM.cpp

konczakp wrote:There is some progress … I can see some readings but they are unstable and unreliable. And it is not showing a pressure …

… also beware that Touch-Screen-Library_STM shows clearly that when use in AVR mode, it is using 10bits ADC, so 1024 range, while in STM32 it is 12bits with 4096 range.

This is working sketch in which only range left for calibration

//for STM32
#define YP PB0 // RS must be an analog pin, use "An" notation!
#define XM PA0 // CS must be an analog pin, use "An" notation!
#define YM PB7 // D0 can be a digital pin
#define XP PA1 // D1 can be a digital pin

#define pressureThreshhold 20
#define NUMSAMPLES 6

void setup(void) {
Serial.begin(115200);
}

void loop(void) {

// For better pressure precision, we need to know the resistance
// between X+ and X- Use any multimeter to read it
// For the one we're using, its 300 ohms (rxplate) across the X plate

getPoint_new(XP, YP, XM, YM, 300);

}

void getPoint_new(byte xp, byte yp, byte xm, byte ym, int rxplate) {

int x, y, z;
int samples[NUMSAMPLES];
byte i, valid;

gpio_dev* xp_port = digitalPinToPort(xp);
gpio_dev* yp_port = digitalPinToPort(yp);
gpio_dev* xm_port = digitalPinToPort(xm);
gpio_dev* ym_port = digitalPinToPort(ym);

byte xp_pin = digitalPinToBitMask(xp);
byte yp_pin = digitalPinToBitMask(yp);
byte xm_pin = digitalPinToBitMask(xm);
byte ym_pin = digitalPinToBitMask(ym);

valid = 1;

pinMode(yp, INPUT);
pinMode(ym, INPUT);

*portOutputRegister(yp_port) &= ~yp_pin;
*portOutputRegister(ym_port) &= ~ym_pin;

pinMode(xp, OUTPUT);
pinMode(xm, OUTPUT);

*portOutputRegister(xp_port) |= xp_pin;
*portOutputRegister(xm_port) &= ~xm_pin;

for (i=0; i<NUMSAMPLES; i++) {
samples[i] = analogRead(yp);
}

insert_sort(samples, NUMSAMPLES);

x = (4096-samples[NUMSAMPLES/2]);

pinMode(xp, INPUT);
pinMode(xm, INPUT);

*portOutputRegister(xp_port) &= ~xp_pin;

pinMode(yp, OUTPUT);
*portOutputRegister(yp_port) |= yp_pin;
pinMode(ym, OUTPUT);

for (i=0; i<NUMSAMPLES; i++) {
samples[i] = analogRead(xm);
}

insert_sort(samples, NUMSAMPLES);

y = (4096-samples[NUMSAMPLES/2]);

// Set X+ to ground
pinMode(xp, OUTPUT);
*portOutputRegister(xp_port) &= ~xp_pin;

// Set Y- to VCC
*portOutputRegister(ym_port) |= ym_pin;

// Hi-Z X- and Y+
*portOutputRegister(yp_port) &= ~yp_pin;
pinMode(yp, INPUT);

int z1 = analogRead(xm);
int z2 = analogRead(yp);

if (rxplate != 0) {

// now read the x
float rtouch;
rtouch = z2;
rtouch /= z1;
rtouch -= 1;
rtouch *= x;
rtouch *= rxplate;
rtouch /= 1024;
z = rtouch;

} else {

z = (1023-(z2+z1));

}

if (! valid) {
z = 0;
}

if (z > pressureThreshhold && z < 1000){
Serial.print("X = "); Serial.print(x);
Serial.print("\tY = "); Serial.print(y);
Serial.print("\tPressure = "); Serial.println(z);
}

}

static void insert_sort(int array[], uint8_t size) {
uint8_t j;
int save;

for (int i = 1; i < size; i++) {
save = array[i];
for (j = i; j >= 1 && save < array[j - 1]; j--)
array[j] = array[j - 1];
array[j] = save;
}
}

First, you need to be aware that this lib use straight 8 bits of PA7-PA0 for data bus. Moving PA0 to CS you will need to change the write8() function too.
BTW, there was a typo in the comments of Adafruit_ILI9341_8bit_STM.h :
//Pin stm32 |PA7|PA6|PA5|PA4|PA3|PA2|PC1|PA0|

Switching PORTA to PORTB sounds good. How can I do This ?

Look here :

#define TFT_CNTRL GPIOB
#define TFT_DATA GPIOA


So doing this way I should get :

Port data |D7 |D6 |D5 |D4 |D3 |D2 |D1 |D0 |
Pin stm32 |PB7|PB6|PB5|PB4|PB3|PB2|PB1|PB0|

Control pins |RD |WR |RS |CS |RST|
Pin stm32 |PA4|PA5|PA6|PA7|PA8|

But there is small problem. There is no PB2 pin : http://www.stm32duino.com/download/file.php?id=17

PB2 is Boot1, but, I’m not sure if it is usable.

Image

ohhh :/ it is not usable then. So can those pins be shifted to start not from PB0 but from PB3 ? If yes then how to do this in those functions? Will this affect SPI2? I hope not because I will need to use it.

konczakp wrote:ohhh :/ it is not usable then. So can those pins be shifted to start not from PB0 but from PB3 ? If yes then how to do this in those functions? Will this affect SPI2? I hope not because I will need to use it.

in this way it will cut me off from both SPI. I need one of the SPI to be usable.

ahull wrote:PB2 is Boot1, but, I’m not sure if it is usable.

You mean a hardware pull down like 4,7kOhm between PB2 and GND? In this way I’ll be able to use this pin normally and also be able to enter bootloader ?

Yes ! in my case, I’m using 10K, and within my firmware, the PDB2 is then set as a GPIO output in setup().

okey, so as a conclusion I will set in library code

#define TFT_CNTRL GPIOA
#define TFT_DATA GPIOB


Boot1 is ignored unless Boot0 is pulled high.

The Maple mini leaves Boot1 floating.

This only becomes an issue if you want to flash via Serial, in which. case you need to make sure Boot1 is pulled low, otherwise flashing via serial is unreliable as the code can get flashed into RAM not ROM

Unfortunately after changes screen is not working. I’ve change connections to :

Port data |D7 |D6 |D5 |D4 |D3 |D2 |D1 |D0 |
Pin stm32 |PB7|PB6|PB5|PB4|PB3|PB2|PB1|PB0|

Control pins |RD |WR |RS |CS |RST|
Pin stm32 |PA4|PA5|PA6|PA7|PA8|