![](/media/cache/profiles/1f50893f80d6830d62765ffad7721742.50x50_q85.jpg)
A general demonstration color etch-a-sketch program using the QVGA TFT with HX8347D controller, Orange Board. Saves touchscreen calibaration data saved in tft.ini. Creates /local/tft.ini if missing. Also included is an Ethernet NTP client to update the RTC. Assumes all other Orange Board devices attached: Text LCD, SDHC Flash, Ethernet.
Dependencies: EthernetNetIf TextLCD mbed
Diff: Touch_tft/touch_tft.cpp
- Revision:
- 0:e065ca40f28a
diff -r 000000000000 -r e065ca40f28a Touch_tft/touch_tft.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Touch_tft/touch_tft.cpp Mon Aug 01 16:29:58 2011 +0000 @@ -0,0 +1,228 @@ +/* mbed library for resistive touch pads + * uses 4 pins - 2 IO and 2 Analog + + * c 2011 Peter Drescher - DC2PD + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + + +#include "touch_tft.h" +#include "mbed.h" + +#define threshold 0x2000 // threshold to detect pressed + +touch_tft::touch_tft(PinName xp, PinName xm, PinName yp, PinName ym, + PinName mosi, PinName miso, PinName sclk, PinName cs, PinName reset,const char* name): + _xp(xp),_xm(xm),_yp(yp),_ym(ym),_ax(xp),_ay(yp), + SPI_TFT(mosi,miso,sclk,cs,reset,name) { + xa = xp; + ya = yp; + +} + +point touch_tft::get_touch() { + unsigned short x1 = 0,x2 = 0, y1 = 0, y2 = 0; + unsigned int s1 = 0,s2 = 0,d1 , d2; + point p; + + do { + // read y voltage + _xp.output(); + _xm.output(); + switch (orientation) { + case(0): + case(3): + _xp = 1; + _xm = 0; + break; + case(1): + case(2): + _xp = 0; + _xm = 1; + break; + } + _ym.input(); // y- have to be passive + AnalogIn Ay(ya); // we have to call the constructor to switch to analog mode + wait_us(10); + y1 = Ay.read_u16(); // get y voltage + d1 = (y1 > y2)? (y1-y2) : (y2-y1); + if (((y1 < 8000) && (d1 < 2000)) || ((y1 > 8000) && (d1 < 150))) s1 ++; + else { + if (s1 > 0) s1 --; + } + y2 = y1; + // debug + //locate(1,7); + //printf("d: %4d y: %5d s1: %4d",d1,y1,s1); + + // read x voltage + _yp.output(); + _ym.output(); + switch (orientation) { + case(0): + case(1): + _yp = 1; + _ym = 0; + break; + case(2): + case(3): + _yp = 0; + _ym = 1; + break; + } + _xm.input(); // x- have to be passive + AnalogIn Ax(xa); // we have to call the constructor to switch to analog mode + wait_us(10); + x1 = Ax.read_u16(); // get x voltage + d2 = (x1 > x2)? (x1-x2) : (x2-x1); + if (((x1 < 8000) && (d2 < 2000)) || ((x1 > 8000) && (d2 < 150))) s2 ++; + else { + if (s2 > 0) s2 --; + } + x2 = x1; + // debug + //locate(1,8); + //printf("d: %4d x: %5d s2: %4d",d2,x1,s2); + + } while (s1 < 3 || s2 < 3); // read until we have three samples close together + switch (orientation) { + case(0): + case(2): + p.y = (x1+x2) / 2; // average of two sample + p.x = (y1+y2) / 2; + break; + case(1): + case(3): + p.x = (x1+x2) / 2; // average of two sample + p.y = (y1+y2) / 2; + break; + } + return(p); +} + +void touch_tft::calibrate(void) { + int i; + int a = 0,b = 0,c = 0, d = 0; + int pos; + point p; + + cls(); + line(0,3,6,3,White); + line(3,0,3,6,White); + pos = columns() / 2 - 5; + locate(pos,5); + printf("press cross"); + locate(pos,6); + printf("to calibrate"); + for (i=0; i<5; i++) { + do { + p = get_touch(); + } while (p.x < 0x2000 | p.y < 0x2000); // wait for touch + a += p.x; + b += p.y; + } + a = a / 5; + b = b / 5; + locate(pos,5); + printf("OK "); + do { + p = get_touch(); + } while (p.y > 0x2000 | p.x > 0x2000); // wait for no touch + + cls(); + line(width() -5, height() - 8,width() - 5,height() -1,White); // paint cross + line(width() - 8,height() - 5,width() - 1,height() - 5,White); + locate(pos,5); + printf("press cross"); + locate(pos,6); + printf("to calibrate"); + for (i=0; i<5; i++) { + do { + p = get_touch(); + } while (p.y < 0x2000 | p.x < 0x2000); // wait for touch + c+= p.x; + d+= p.y; + } + c = c / 5; + d = d / 5; + + locate(pos,5); + printf("OK "); + do { + p = get_touch(); + } while (p.y > 0x2000 | p.x > 0x2000); // wait for no touch + + cls(); + + x_off = a; + y_off = b; + + i = c-a; // delta x + pp_tx = i / (width() - 6); + + i = d-b; // delta y + pp_ty = i / (height() - 6); +} + +// kb adds \/ \/ \/ +unsigned short pp_txx, pp_tyy; +unsigned short xx_off,yy_off; +//unsigned short pp_txxx, pp_tyyy; +//unsigned short xxx_off,yyy_off; + +unsigned short touch_tft::getCalDataX() { + pp_txx = pp_tx; + return(pp_txx); +} + +unsigned short touch_tft::getCalDataY() { + pp_tyy = pp_ty; + return(pp_tyy); +} + +unsigned short touch_tft::getCalOffX() { + xx_off = x_off; + return(xx_off); +} + +unsigned short touch_tft::getCalOffY() { + yy_off = y_off; + return(yy_off); +} + +void touch_tft::setCalDataX(unsigned short pp_txx) { + pp_tx = pp_txx; +} +void touch_tft::setCalDataY(unsigned short pp_tyy) { + pp_ty = pp_tyy; +} +void touch_tft::setCalOffX(unsigned short xx_off) { + x_off = xx_off; +} +void touch_tft::setCalOffY(unsigned short yy_off) { + y_off = yy_off; +} + +// kb adds /\ /\ /\ + +point touch_tft::to_pixel(point a_point) { + point p; + + p.x = (a_point.x - x_off) / pp_tx; + if(p.x > width()) p.x = 0; + p.y = (a_point.y - y_off) / pp_ty; + if(p.y > height()) p.y = 0; + return (p); +} + +bool touch_tft::is_touched(point a){ + if (a.x > threshold & a.y > threshold) return(true); + else return(false); +}