ESP32 Smartphone Prototype

#include <Arduino.h>
#include <SPI.h>
#include <Adafruit_GFX.h>
#include <Adafruit_ST7789.h>
#include <driver/i2s.h>
#include <math.h>
#include <XPT2046_Touchscreen.h>
#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <HTTPClient.h>
#include <FS.h>
using fs::FS;
#include <WebServer.h>
#include <Preferences.h>
#include <time.h>
#include <SD.h>
#include <BLEDevice.h>
#include <BLEScan.h>
#include <AudioFileSourceSD.h>
#include <AudioFileSourceICYStream.h>
#include <AudioGeneratorMP3.h>
#include <AudioGeneratorWAV.h>
#include <TJpg_Decoder.h>
#include <PNGdec.h>

// Single-row ST7789 module, XPT2046-compatible touch and integrated SD.
// Shared SPI: SCK/T_CLK/SD_SCK=12, MOSI/T_DIN/SD_MOSI=11,
// T_DO/SD_MISO=13; display MISO is unused. CS: LCD=10, touch=7, SD=6.
// LED backlight: 3V3 through external 100-ohm resistor (no GPIO).
// Do not use GPIO3: it is reserved as a strapping pin on this board.
class PocketDisplay : public Adafruit_ST7789 {
public:
  PocketDisplay() : Adafruit_ST7789(&SPI,10,9,8) {}
  // init() invokes begin() internally. Slow the initialization commands too,
  // not just the drawing that happens after init().
  void begin(uint32_t freq=0) override {
    Adafruit_ST77xx::begin(10000000);
  }
  void drawString(const String &s,int x,int y,int font=2) {
    setCursor(x,y); print(s);
  }
  void drawCentreString(const String &s,int x,int y,int font=2) {
    setCursor(x-s.length()*6*textsize_x/2,y); print(s);
  }
};
PocketDisplay tft;
XPT2046_Touchscreen touch(7);
const uint16_t TFT_WHITE=ST77XX_WHITE, TFT_YELLOW=ST77XX_YELLOW;
int volume=15;
bool audioReady=false;
void initAudio() {
  pinMode(5,OUTPUT); digitalWrite(5,LOW); // amplifier muted until test
  i2s_config_t c={};
  c.mode=(i2s_mode_t)(I2S_MODE_MASTER|I2S_MODE_TX);
  c.sample_rate=16000;
  c.bits_per_sample=I2S_BITS_PER_SAMPLE_16BIT;
  c.channel_format=I2S_CHANNEL_FMT_RIGHT_LEFT;
  c.communication_format=I2S_COMM_FORMAT_STAND_I2S;
  c.intr_alloc_flags=0; c.dma_buf_count=4; c.dma_buf_len=128;
  c.use_apll=false; c.tx_desc_auto_clear=true;
  i2s_pin_config_t pins={};
  pins.mck_io_num=I2S_PIN_NO_CHANGE; pins.bck_io_num=1;
  pins.ws_io_num=2; pins.data_out_num=4; pins.data_in_num=I2S_PIN_NO_CHANGE;
  if(i2s_driver_install(I2S_NUM_0,&c,0,nullptr)!=ESP_OK)return;
  if(i2s_set_pin(I2S_NUM_0,&pins)!=ESP_OK)return;
  i2s_zero_dma_buffer(I2S_NUM_0); audioReady=true;
}
void playTone() {
  if(!audioReady)return;
  i2s_zero_dma_buffer(I2S_NUM_0);
  digitalWrite(5,HIGH); // left channel; identical samples in both channels
  int16_t samples[256];
  for(int block=0;block<16;++block) {
    for(int j=0;j<128;++j) {
      int n=block*128+j;
      float envelope=fminf(1.0f,fminf(n/160.0f,(2047-n)/160.0f));
      int16_t v=(int16_t)((8000*volume/100.0f)*envelope*sinf(2*PI*660*n/16000.0f));
      samples[2*j]=samples[2*j+1]=v;
    }
    size_t written=0;
    i2s_write(I2S_NUM_0,samples,sizeof(samples),&written,portMAX_DELAY);
  }
  // Let the final DMA blocks finish before muting the amp.
  delay(40); digitalWrite(5,LOW); i2s_zero_dma_buffer(I2S_NUM_0);
}
TaskHandle_t audioTaskHandle=nullptr;
void audioWorker(void *) {
  while(true) {ulTaskNotifyTake(pdTRUE,portMAX_DELAY);playTone();}
}
void soundTest();
WebServer server(80);
Preferences prefs;
uint16_t BG=0x1082, FG=0xFFFF, GRAY=0x2945;
bool lightMode=false; int settingsTab=0;
void applyTheme(){BG=lightMode?0xEF7D:0x1082;FG=lightMode?0x0843:0xFFFF;GRAY=lightMode?0xCE79:0x2945;}
enum Page {HOME,FILES,IMAGES,CALC,SETTINGS,RADIO,NOTES,TIMER,STOPWATCH,PREVIEW,APPS,ACTIONS,PLAYER,CALENDAR,CHAT,GAME,GAMELIST,CHESS,CONTROL,TICTACTOE,MEMORY,MUSIC,MAKER,UTILITY};
Page page=HOME;
bool dirty=true,down=false,portal=false,connectPending=false,sdReady=false;
String ssid,password,lastClock,lastDate,lastTimer,note,message;
// Versioned affine calibration handles exchanged axes, mirroring and skew.
struct TouchMap { float x[3], y[3]; } touchMap;
const int16_t targetX[5]={24,215,215,24,120};
const int16_t targetY[5]={24,24,295,295,160};
float rawX[5],rawY[5];
uint8_t touchSamples=0;
int32_t touchSumX=0,touchSumY=0;
int16_t sampleMinX=4095,sampleMaxX=0,sampleMinY=4095,sampleMaxY=0;
uint32_t releaseSince=0;
int cal=0,utcOffset=0;
uint32_t nextTouch=0,nextTick=0,elapsed=0,started=0;
bool running=false,timerOn=false,ringing=false;
uint32_t countdownDeadline=0,timerMinutes=5,lastRing=0;
uint32_t displayHz=10000000;
String calcValue="0",calcStored=""; double accumulator=0; char operation=0; bool fresh=true;
String folder="/",paths[6],names[6]; bool dirs[6]; int filePage=0,fileCount=0; bool moreFiles=false;
File bmpFile;
uint32_t bmpOffset=0,bmpStride=0;
int bmpW=0,bmpH=0,bmpRow=0; bool bmpBottom=true;
uint8_t pixels[240*3]; uint16_t linePixels[240];
String previewText;
int wifiState=-3; // -3 idle, -2 scanning, -1 failed, >=0 result count
BLEScan *bleScan=nullptr;
volatile bool bleDone=false;
bool bleBusy=false;
String radioLines[4];
String scanRows[32],scanSsids[32],scanJson="[]"; bool wifiCompose=false; String wifiDraft,chosenSsid; int scanCount=0,scanOffset=0;
String scanKind="No scan yet";
void showScanRows(){for(int i=0;i<4;i++)radioLines[i]=scanOffset+i<scanCount?scanRows[scanOffset+i]:"";}

#include "lvgl_grid.h"
void text(const String &s,int x,int y,int size=1) {
  uiWidget(s,x,y,240-x,size>=2?32:18,false,0,size);
}
void button(const String &s,int x,int y,int w,int h) {
  uiWidget(s,x,y,w,h,true,lightMode?0x387b9c:0x253e58);
}
bool hit(int x,int y,int a,int b,int w,int h) {return x>=a&&x<a+w&&y>=b&&y<b+h;}
void valueBox(const String &s,int x,int y,int w,int h,int size=1) {
  uiWidget(s,x,y,w,h,false,0,size);
}
void resetTouchSamples() {
  touchSamples=0;touchSumX=touchSumY=0;
  sampleMinX=sampleMinY=4095;sampleMaxX=sampleMaxY=0;
}
void calibrationScreen(bool retry=false) {
  tft.fillScreen(BG);
  text("Touch setup "+String(cal)+"/5",20,70,2);
  text("Hold cross steady, then lift",20,105);
  text("Use a blunt plastic stylus",20,120);
  text(retry?"Not accurate - try again":"Touch the centre of each cross",20,200);
  int x=targetX[cal-1],y=targetY[cal-1];
  tft.drawCircle(x,y,12,FG);
  tft.drawLine(x-16,y,x+16,y,FG);tft.drawLine(x,y-16,x,y+16,FG);
}
void startCalibration() {
  cal=1;down=true;releaseSince=0;resetTouchSamples();calibrationScreen();
}
bool fitTouchMap() {
  // Normalized raw coordinates keep the least-squares system well scaled.
  float m[3][5]={};
  for(int k=0;k<5;k++) {
    float v[3]={rawX[k]/4095.0f,rawY[k]/4095.0f,1};
    for(int i=0;i<3;i++) {
      for(int j=0;j<3;j++)m[i][j]+=v[i]*v[j];
      m[i][3]+=v[i]*targetX[k];m[i][4]+=v[i]*targetY[k];
    }
  }
  for(int i=0;i<3;i++) {
    int pivot=i;
    for(int k=i+1;k<3;k++)if(fabsf(m[k][i])>fabsf(m[pivot][i]))pivot=k;
    if(fabsf(m[pivot][i])<0.0001f)return false;
    for(int j=0;j<5;j++){float v=m[i][j];m[i][j]=m[pivot][j];m[pivot][j]=v;}
    float d=m[i][i];for(int j=i;j<5;j++)m[i][j]/=d;
    for(int k=0;k<3;k++)if(k!=i){float f=m[k][i];for(int j=i;j<5;j++)m[k][j]-=f*m[i][j];}
  }
  TouchMap candidate;
  for(int i=0;i<3;i++){candidate.x[i]=m[i][3];candidate.y[i]=m[i][4];}
  for(int k=0;k<5;k++) {
    float x=rawX[k]/4095.0f,y=rawY[k]/4095.0f;
    float dx=candidate.x[0]*x+candidate.x[1]*y+candidate.x[2]-targetX[k];
    float dy=candidate.y[0]*x+candidate.y[1]*y+candidate.y[2]-targetY[k];
    if(!isfinite(dx)||!isfinite(dy)||dx*dx+dy*dy>14*14)return false;
  }
  touchMap=candidate;return true;
}
void acceptCalibrationPoint(float x,float y) {
  rawX[cal-1]=x;rawY[cal-1]=y;
  if(cal<5){++cal;calibrationScreen();return;}
  if(!fitTouchMap()){cal=1;calibrationScreen(true);return;}
  prefs.putBytes("touchMap",&touchMap,sizeof(touchMap));
  prefs.putUInt("touchVer",2);
  cal=0;dirty=true;
}
#include "apps.h"
void mountSD() {
  stopTrack();
  SD.end();sdReady=SD.begin(6,SPI,10000000);
  if(sdReady&&SD.cardType()==CARD_NONE){SD.end();sdReady=false;}
  message=sdReady?"SD ready":"No SD: insert FAT32 card";
}
void listFiles() {
  fileCount=0;moreFiles=false;
  if(!sdReady){message="No SD. Settings > Mount SD";return;}
  File dir=SD.open(folder);
  if(!dir||!dir.isDirectory()){folder="/";message="Cannot open folder";return;}
  int skip=filePage*6,seen=0;
  // At most 32 pages per folder keeps navigation bounded.
  while(true) {
    File f=dir.openNextFile();if(!f)break;
    String name=f.name();int slash=name.lastIndexOf('/');if(slash>=0)name=name.substring(slash+1);
    String lower=name;lower.toLowerCase();bool isDir=f.isDirectory();f.close();
    if(page==IMAGES&&!isDir&&!lower.endsWith(".bmp")&&!lower.endsWith(".jpg")&&!lower.endsWith(".jpeg")&&!lower.endsWith(".png"))continue;
    if(seen++<skip)continue;
    if(fileCount==6){moreFiles=true;break;}
    names[fileCount]=(isDir?"[+] ":"")+name;
    paths[fileCount]=(folder=="/"?"/":folder+"/")+name;dirs[fileCount]=isDir;fileCount++;
  }
  dir.close();message="";
}
uint16_t read16(File &f) {uint16_t a=f.read();return a|((uint16_t)f.read()<<8);}
uint32_t read32(File &f) {uint32_t a=read16(f);return a|((uint32_t)read16(f)<<16);}
void openPreview(String path) {
  bmpFile.close();jpgPath="";previewText="";message="";dirty=true;
  String lower=path;lower.toLowerCase();
  File f=SD.open(path,FILE_READ);
  if(!f){message="Cannot open file";return;}
  if(lower.endsWith(".png")||lower.endsWith(".jpg")||lower.endsWith(".jpeg")) {
    f.close(); jpgPath=path; page=PREVIEW; return;
  } else if(lower.endsWith(".mp3")||lower.endsWith(".wav")||lower.endsWith(".waw")) {
    f.close();startTrack(path);page=PLAYER;return;
  } else if(lower.endsWith(".mp4")) {
    f.close();message="MP4 decoding unsupported on S3";return;
  } else if(lower.endsWith(".bmp")) {
    bool valid=read16(f)==0x4D42;read32(f);read32(f);uint32_t offset=read32(f),header=read32(f);
    int32_t w=(int32_t)read32(f),h=(int32_t)read32(f);
    uint16_t planes=read16(f),depth=read16(f);uint32_t compression=read32(f);
    if(!valid||header<40||w<1||w>240||h==0||h>232||h< -232||planes!=1||depth!=24||compression!=0) {
      message="Use 24-bit BMP <=240x232";f.close();return;
    }
    bmpW=w;bmpH=abs(h);bmpBottom=h>0;bmpOffset=offset;bmpStride=(w*3+3)&~3;
    if((uint64_t)offset+(uint64_t)bmpStride*bmpH>f.size()){message="Truncated BMP";f.close();return;}
    bmpRow=0;bmpFile=f;
  } else if(lower.endsWith(".txt")||lower.endsWith(".csv")) {
    while(f.available()&&previewText.length()<500) {char c=f.read();previewText+=c=='\n'?'\n':((c>=32&&c<127)?c:' ');}
    f.close();
  } else {f.close();message="Preview: BMP, TXT or CSV only";}
  page=PREVIEW;dirty=true;
}
void drawImageRow() {
  if(page!=PREVIEW||!bmpFile||bmpRow>=bmpH)return;
  int source=bmpBottom?bmpH-1-bmpRow:bmpRow;
  if(!bmpFile.seek(bmpOffset+source*bmpStride)||bmpFile.read(pixels,bmpW*3)!=(size_t)bmpW*3) {
    bmpFile.close();message="SD read failed";dirty=true;return;
  }
  for(int i=0;i<bmpW;i++)linePixels[i]=tft.color565(pixels[i*3+2],pixels[i*3+1],pixels[i*3]);
  // SD transaction is finished before starting the display transaction.
  tft.drawRGBBitmap((240-bmpW)/2,38+bmpRow,linePixels,bmpW,1);
  if(++bmpRow>=bmpH)bmpFile.close();
}
void saveNote() {
  prefs.putString("note",note);message="Saved on device";
  if(sdReady){SD.remove("/note.txt");File f=SD.open("/note.txt",FILE_WRITE);if(f){bool ok=f.print(note)==note.length();f.close();message=ok?"Saved + SD /note.txt":"SD write failed";}else message="Device saved; SD failed";}
}
void switchPage(Page p) {
  deleteConfirm=false;
  // Web control stays available until explicitly closed.
  if(page==PLAYER && p!=PLAYER)stopTrack();
  jpgPath="";
  if(page==PREVIEW)bmpFile.close();
  page=p;message="";dirty=true;lastClock="";lastDate="";lastTimer="";
  if(p!=NOTES&&chatCompose){note=savedDraft;chatCompose=false;}
  if(p!=NOTES&&wifiCompose){note=wifiDraft;wifiCompose=false;}
  if(p==FILES||p==IMAGES){folder="/";filePage=0;listFiles();}
}
void bleComplete(BLEScanResults results){bleDone=true;}
void startBLE() {
  stopTrack();
  if(bleBusy)return;
  if(wifiState==-2){message="Wait for Wi-Fi scan";dirty=true;return;}
  if(!bleScan){BLEDevice::init("Pocket");bleScan=BLEDevice::getScan();bleScan->setActiveScan(true);}
  for(int i=0;i<4;i++)radioLines[i]="";
  bleDone=false;bleBusy=true;bleScan->clearResults();
  if(!bleScan->start(8,bleComplete,false)){bleBusy=false;message="BLE scan failed";}
  else message="Active BLE scan (8 seconds)";
  dirty=true;
}
void startWifi() {
  stopTrack();
  if(bleBusy||wifiState==-2){message="Wait for current scan";dirty=true;return;}
  WiFi.scanDelete();wifiState=-2;
  for(int i=0;i<4;i++)radioLines[i]="";
  int result=WiFi.scanNetworks(true);if(result==WIFI_SCAN_FAILED){wifiState=-1;message="Wi-Fi scan failed";}else message="Scanning Wi-Fi...";
  dirty=true;
}
void draw() {
  if(locked) { drawLockScreen(); dirty=false; return; }
  tft.fillScreen(BG);
  if(page>=APPS) {drawExtra();}
  else if(page==HOME) {
    drawWallpaper();
    tft.fillRoundRect(6,3,228,25,8,0x0843);
    uiWidget(WiFi.status()==WL_CONNECTED?LV_SYMBOL_WIFI " Wi-Fi":"Local",149,6,83,20,false,0);
    uiWidget("USB",104,6,40,20,false,0);
    drawAppGrid(false);
  } else {
    const char *titles[]={"","SD files","Gallery","Calculator","Settings","Wi-Fi / BLE scan","Notes","Countdown timer","Stopwatch","SD preview"};
    text(page==NOTES&&wifiCompose?"WiFi password":titles[page],8,10,2);button("Home",8,280,224,32);
    if(page==FILES||page==IMAGES) {
      text((moving?"Up: ":"")+folder.substring(0,moving?32:37),8,34);
      for(int i=0;i<fileCount;i++)button(names[i].substring(0,34),8,50+i*28,224,25);
      button(moving?"Paste":"Up",8,224,65,28);button("Prev",87,224,65,28);button("Next",167,224,65,28);
      if(!fileCount&&!message.length())text("Folder is empty",8,80);
    } else if(page==CALC) {
      const char *keys[]={"7","8","9","/","4","5","6","*","1","2","3","-","C","0",".","+"};
      for(int i=0;i<16;i++)button(keys[i],8+(i%4)*57,75+(i/4)*38,53,34);
      button("=",8,232,224,32);
    } else if(page==SETTINGS) {
      if(settingsTab==0){
        const String rows[]={"Appearance: "+String(lightMode?"Light":"Dark"),"Speaker / volume: "+String(volume)+"%","Wi-Fi / connect / BLE scan","Phone / web / security","Display / SD / time / lock"};
        for(int i=0;i<5;i++){tft.fillRect(8,44+i*40,224,36,GRAY);text(rows[i],14,57+i*40);text(">",218,57+i*40);}
      } else if(settingsTab==1){
        text("Wired speaker volume",8,48,2);text(String(volume)+"%",90,90,2);
        button("-5",8,125,105,38);button("+5",127,125,105,38);
        button("Stop music",8,174,105,32);button("Test",127,174,105,32);
        button("Ringtone test",8,212,224,24);button("Settings list",8,240,224,28);
      } else if(settingsTab==2){
        text("Connect phone to Pocket-Setup",8,48);text("AP password: pocket123",8,70);
        text("Web: "+WiFi.softAPIP().toString(),8,102);text("User: pocket",8,124);text("Pass: "+webPass,8,146);
        text("Change passwords in web settings",8,185);button("Settings list",8,240,224,28);
      } else {
        button("Touch calibration",8,44,224,30);button("Mount SD",8,80,105,30);button("Lock",127,80,105,30);
        text("Time zone: "+String(utcOffset)+" min",8,132);button("-15 min",8,154,105,32);button("+15 min",127,154,105,32);
        text("Set time from phone web controls",8,210);button("Settings list",8,240,224,28);
      }
    } else if(page==RADIO) {
      text(WiFi.status()==WL_CONNECTED?("Online: "+WiFi.SSID()).substring(0,36):"WiFi disconnected",8,32);
      button("Scan WiFi",8,46,105,28);button("Scan BLE",127,46,105,28);
      for(int i=0;i<4;i++){tft.drawRect(8,80+i*22,224,21,0x4A69);text(radioLines[i].substring(0,36),11,86+i*22);}
      button("Prev",8,174,65,26);button("Next",87,174,65,26);button("AP on",167,174,65,26);
      if(portal){text("Web: "+WiFi.softAPIP().toString(),8,207);text("User: pocket  Pass: "+webPass,8,220);text("AP: Pocket-Setup / pocket123",8,233);}
      text(scanKind=="Wi-Fi"?"Tap network to connect":"BLE scan only; no BT audio",8,247);
    } else if(page==NOTES) {
      String keys=keyChars();
      int pos=0;for(int row=0;row<4;row++){for(int col=0;col<keyboardRowCount(row);col++)uiWidget(String(keys[pos++]),keyboardRowX(row)+col*24+1,91+row*29,22,27,true,row==0?0x176e96:0x253e58,2);}
      button("Space",8,211,68,28);button("Del",84,211,68,28);button(wifiCompose?"Join":chatCompose?"Send":"Save",160,211,72,28);
      button(keyMode==0?"ABC":keyMode==1?"abc":keyMode==2?"123":"#%$",8,244,58,27);text("120 chars",82,254);
    } else if(page==TIMER) {
      text("Duration: "+String(timerMinutes)+" min",8,80,2);
      button("-1 min",8,118,105,34);button("+1 min",127,118,105,34);
      button(timerOn?"Cancel":"Start",8,169,105,38);button("Silence",127,169,105,38);
      text("Keep USB connected.",8,226);text("Timer does not survive reset.",8,243);
    } else if(page==STOPWATCH) {
      button(running?"Pause":"Start",8,155,105,42);button("Reset",127,155,105,42);
    } else if(page==PREVIEW) {
      button("Back to files",8,280,224,32);
      if(jpgPath.length()){String e=jpgPath;e.toLowerCase();if(e.endsWith(".png"))drawPng(jpgPath);else drawJpeg(jpgPath);}
      if(previewText.length()) {
        int col=0,row=0;String line;
        for(unsigned i=0;i<previewText.length()&&row<27;i++) {
          char c=previewText[i];if(c=='\n'||col==37){text(line,8,38+row++*8);line="";col=0;if(c=='\n')continue;}
          line+=c;col++;
        }if(row<27)text(line,8,38+row*8);
      }
    }
  }
  if(message.length()&&page!=HOME)text(message.substring(0,37),8,266);
  dirty=false;lastClock="";lastDate="";lastTimer="";
}
void dynamicValues() {
  if(locked) { if(!unlockPad){time_t n=time(nullptr);String minute=String((long)(n/60));if(minute!=lastClock){lastClock=minute;drawLockScreen();}} return; }
  if(page==HOME) {
    time_t now=time(nullptr);String clock="--:--",date="Set time on phone";
    if(now>=1700000000){now+=utcOffset*60;struct tm t;gmtime_r(&now,&t);char b[32];strftime(b,sizeof(b),"%H:%M",&t);clock=b;strftime(b,sizeof(b),"%a %d %b %Y",&t);date=b;}
    if(clock!=lastClock){valueBox(clock,12,6,86,22);lastClock=clock;}
    if(date!=lastDate){valueBox(date+"  |  "+weatherLine,8,37,224,32);lastDate=date;}
  } else if(page==CALC) {
    if(calcValue!=lastClock){valueBox(calcValue.substring(0,18),8,44,224,20,2);lastClock=calcValue;}
  } else if(page==NOTES) {
    if(note!=lastClock) {
      String shown=note;if(wifiCompose){shown="";for(unsigned i=0;i<note.length();i++)shown+='*';}
      uiWidget(shown,8,42,224,42,false,0);lastClock=note;
    }
  } else if(page==TIMER||page==STOPWATCH) {
    uint32_t sec=page==TIMER?(timerOn?(uint32_t)max(0L,(long)(countdownDeadline-millis()+999))/1000:0):(elapsed+(running?millis()-started:0))/1000;
    char b[32];snprintf(b,sizeof(b),"%02lu:%02lu:%02lu",(unsigned long)(sec/3600),(unsigned long)((sec/60)%60),(unsigned long)(sec%60));
    String v=ringing&&page==TIMER?"TIME UP!":String(b);
    if(v!=lastTimer){valueBox(v,8,page==TIMER?42:80,224,28,3);lastTimer=v;}
  }
}
void calculator(char key) {
  if(key=='C'){calcValue="0";accumulator=0;operation=0;fresh=true;return;}
  if((key>='0'&&key<='9')||key=='.') {
    if(fresh){calcValue=key=='.'?"0":"";fresh=false;}
    if(key=='.'&&calcValue.indexOf('.')>=0)return;
    if(calcValue.length()<15){if(calcValue=="0"&&key!='.')calcValue="";calcValue+=key;}return;
  }
  double rhs=calcValue.toDouble();
  if(operation) {
    if(operation=='/'&&rhs==0){calcValue="Error";operation=0;fresh=true;return;}
    switch(operation){case '+':accumulator+=rhs;break;case '-':accumulator-=rhs;break;case '*':accumulator*=rhs;break;case '/':accumulator/=rhs;break;}
    char b[28];snprintf(b,sizeof(b),"%.8g",accumulator);calcValue=b;
  } else accumulator=rhs;
  operation=key=='='?0:key;fresh=true;
}
void tap(int x,int y) {
  if(locked){
    if(!unlockPad) return;
    // Keep the touch zones aligned with the visible 3-by-3 keypad.
    if(y>=160&&y<256){int col=x/80,row=(y-160)/32; if(col<3&&row<3){char digit='1'+row*3+col; if(unlockInput.length()<6)unlockInput+=digit;lockNotice="";
      if(unlockInput.length()==6){
        if(unlockInput==prefs.getString("lockPass","111122")){locked=false;unlockPad=false;keypadPainted=false;unlockInput="";page=HOME;}
        else{unlockInput="";lockNotice="Wrong passcode";}
      }
      dirty=true;return;}}
    if(y>=258&&y<288){if(x<80){unlockInput="";lockNotice="";dirty=true;}else if(x<160){if(unlockInput.length())unlockInput.remove(unlockInput.length()-1);dirty=true;}else if(unlockInput==prefs.getString("lockPass","111122")){locked=false;unlockPad=false;unlockInput="";dirty=true;}else{unlockInput="";lockNotice="Wrong passcode";dirty=true;} }
    return;
  }
  if(page>=APPS){tapExtra(x,y);return;}
  if(page!=HOME&&y>=280){if(page==PREVIEW){switchPage(FILES);}else switchPage(HOME);return;}
  if(page==HOME) {
    tapPhoneHome(x,y);
  } else if(page==FILES||page==IMAGES) {
    if(y>=30&&y<49&&moving){int slash=folder.lastIndexOf('/');folder=slash>0?folder.substring(0,slash):"/";filePage=0;listFiles();dirty=true;}
    else if(y>=50&&y<218){int i=(y-50)/28;if(i<fileCount){if(dirs[i]){folder=paths[i];filePage=0;listFiles();dirty=true;}else if(!moving){selected=paths[i];page=ACTIONS;dirty=true;}}}
    else if(y>=224&&y<252){if(x<80&&moving){bool ok=moveFile(selected,(folder=="/"?"/":folder+"/")+baseName(selected));moving=false;listFiles();message=ok?"Moved":"Move failed; destination exists?";dirty=true;return;}if(x<80){int slash=folder.lastIndexOf('/');folder=slash>0?folder.substring(0,slash):"/";filePage=0;}else if(x<160){if(filePage)filePage--;}else if(moreFiles)filePage++;listFiles();dirty=true;}
  } else if(page==CALC) {
    if(y>=75&&y<227&&x>=8&&x<236){int col=(x-8)/57,row=(y-75)/38;if(row<4&&col<4)calculator("789/456*123-C0.+"[row*4+col]);}
    else if(y>=232&&y<264)calculator('=');
  } else if(page==SETTINGS) {
    if(settingsTab==0&&y>=44&&y<244){int row=(y-44)/40;
      if(row==0){lightMode=!lightMode;applyTheme();prefs.putBool("light",lightMode);}
      else if(row==1)settingsTab=1;else if(row==2)switchPage(RADIO);else if(row==3)settingsTab=2;else settingsTab=3;
    }else if(y>=240&&y<268)settingsTab=0;
    else if(settingsTab==1){if(y>=125&&y<163){volume=constrain(volume+(x<120?-5:5),0,100);audioOut.SetGain(volume/100.0f);prefs.putInt("volume",volume);}else if(y>=174&&y<206){if(x<120)stopTrack();else soundTest();}else if(y>=212&&y<236){stopTrack();ringAlert();}}
    else if(settingsTab==3){if(y>=44&&y<74)startCalibration();else if(y>=80&&y<110){if(x<120)mountSD();else{locked=true;unlockPad=false;}}else if(y>=154&&y<186){utcOffset=constrain(utcOffset+(x<120?-15:15),-720,840);prefs.putInt("utc",utcOffset);}}
    dirty=true;
  } else if(page==RADIO) {
    if(y>=46&&y<74){if(x<120)startWifi();else startBLE();}
    else if(y>=80&&y<168&&scanKind=="Wi-Fi"){int i=scanOffset+(y-80)/22;if(i<scanCount&&scanSsids[i].length()){chosenSsid=scanSsids[i];wifiDraft=note;wifiCompose=true;note="";switchPage(NOTES);message="Password then Join (blank: open)";}}
    else if(y>=174&&y<200){if(x<80)scanOffset=max(0,scanOffset-4);else if(x<160&&scanOffset+4<scanCount)scanOffset+=4;else if(x>=160)setupPortal();showScanRows();dirty=true;}
  } else if(page==NOTES) {
    if(y>=91&&y<207){int key=keyboardHit(x,y);if(key>=0&&note.length()<120)note+=keyChars()[key];}
    else if(y>=211&&y<239){if(x<80){if(note.length()<120)note+=' ';}else if(x<156){if(note.length())note.remove(note.length()-1);}else{if(wifiCompose){ssid=chosenSsid;password=note.substring(0,63);prefs.putString("ssid",ssid);prefs.putString("pass",password);note=wifiDraft;wifiCompose=false;connectPending=true;switchPage(RADIO);message="Connecting to "+ssid;}else if(chatCompose){outbox=note;note=savedDraft;chatCompose=false;switchPage(CHAT);}else saveNote();dirty=true;}}
    else if(y>=244&&y<271&&x<66){keyMode=(keyMode+1)%4;dirty=true;}
  } else if(page==TIMER) {
    if(y>=118&&y<152){timerMinutes=constrain((int)timerMinutes+(x<120?-1:1),1,180);dirty=true;}
    else if(y>=169&&y<207){if(x<120){timerOn=!timerOn;if(ringing)stopTrack();ringing=false;if(timerOn)countdownDeadline=millis()+timerMinutes*60000;}else {ringing=false;stopTrack();}dirty=true;}
  } else if(page==STOPWATCH&&y>=155&&y<197) {
    if(x<120){if(running)elapsed+=millis()-started;else started=millis();running=!running;dirty=true;}
    else {elapsed=0;started=millis();lastTimer="";}
  }
}
void setup() {
  Serial.begin(115200); // Do not wait for a computer: display starts standalone.
  // Deselect EVERY device before enabling the shared clock and data wires.
  for(int pin:{10,7,6}){digitalWrite(pin,HIGH);pinMode(pin,OUTPUT);}
  digitalWrite(5,LOW);pinMode(5,OUTPUT); // mute amplifier during startup
  digitalWrite(8,HIGH);pinMode(8,OUTPUT);
  delay(150); // allow the external module's supply to settle
  Serial.println("POCKET: starting ST7789, SCK12 MOSI11 CS10 DC9 RST8, 10MHz");
  SPI.begin(12,13,11,10);
  // Library drives RESET low then high and sends sleep-out/display-on.
  // The begin() override above guarantees conservative init command speed.
  tft.init(240,320,SPI_MODE0);
  tft.setRotation(0);tft.setSPISpeed(10000000);tft.setTextWrap(false);
  Serial.println("POCKET: LCD commands sent (no display readback)");
  tft.fillScreen(BG);
  prefs.begin("pocket-s3",false);drawerLoad();
  backgroundPath=prefs.getString("background","/background.jpg");ringtonePath=prefs.getString("ringtone","");
  streamURL=prefs.getString("stream","");
  lightMode=prefs.getBool("light",false);applyTheme();volume=constrain(prefs.getInt("volume",15),0,100);audioOut.SetGain(volume/100.0f);
  // Ignore old 40MHz preference on each cold start while troubleshooting.
  displayHz=10000000;
  Serial.println("POCKET: starting touch and audio");
  touch.begin();touch.setRotation(0);initAudio();
  // Audio decoding and UI share one task: no simultaneous SPI/I2S users.
  Serial.println("POCKET: mounting SD (card optional)");
  mountSD();message="";
  Serial.println(sdReady?"POCKET: SD ready":"POCKET: no SD; continuing without card");
  bool validTouch=prefs.getUInt("touchVer",0)==2 &&
    prefs.getBytesLength("touchMap")==sizeof(touchMap);
  if(validTouch){
    prefs.getBytes("touchMap",&touchMap,sizeof(touchMap));
    for(int i=0;i<3;i++)if(!isfinite(touchMap.x[i])||!isfinite(touchMap.y[i]))validTouch=false;
  }
  // Hold the screen during startup to recover without using misaligned menus.
  if(touch.touched())validTouch=false;
  utcOffset=constrain(prefs.getInt("utc",0),-720,840);note=prefs.getString("note","").substring(0,120);
  // Boot directly into the real UI: no SPI test, splash or animation.
  // Show it before radio/web initialization so networking cannot delay it.
  if(!validTouch)startCalibration();
  else {dirty=true;draw();}
  WiFi.mode(WIFI_STA);ssid=prefs.getString("ssid","");password=prefs.getString("pass","");
  if(ssid.length())WiFi.begin(ssid.c_str(),password.c_str());
  configTime(0,0,"pool.ntp.org","time.nist.gov");
  setupPortal();
  Serial.println("POCKET: setup complete, UI running");
}
void loop() {
  static uint32_t heartbeat=0;
  if(millis()-heartbeat>=5000){
    heartbeat=millis();Serial.printf("POCKET: UI alive, display %lu MHz, SD %s\n",
      (unsigned long)(displayHz/1000000),sdReady?"ready":"absent");
  }
  if(portal)server.handleClient();
  mediaTick();gameTick();
  if(connectPending){connectPending=false;WiFi.begin(ssid.c_str(),password.c_str());}
  if(wifiState==-2) {
    int n=WiFi.scanComplete();
    if(n!=WIFI_SCAN_RUNNING){wifiState=n;message=n>=0?String(n)+" WiFi networks (top 4)":"WiFi scan failed";
      scanCount=constrain(n,0,32);scanOffset=0;scanKind="Wi-Fi";scanJson="[";
      for(int i=0;i<scanCount;i++){scanSsids[i]=WiFi.SSID(i);scanRows[i]=WiFi.SSID(i).substring(0,17)+" "+String(WiFi.RSSI(i))+" ch"+String(WiFi.channel(i));if(i)scanJson+=",";scanJson+="{\"name\":"+jsonString(WiFi.SSID(i))+",\"address\":"+jsonString(WiFi.BSSIDstr(i))+",\"rssi\":"+String(WiFi.RSSI(i))+",\"channel\":"+String(WiFi.channel(i))+",\"secured\":"+(WiFi.encryptionType(i)==WIFI_AUTH_OPEN?"false":"true")+"}";}
      scanJson+="]";showScanRows();
      WiFi.scanDelete();if(page==RADIO)dirty=true;
    }
  }
  if(bleDone) {
    bleDone=false;bleBusy=false;BLEScanResults *results=bleScan->getResults();int n=results->getCount();
    message=String(n)+" BLE devices (first 4)";
    scanCount=min(n,32);scanOffset=0;scanKind="BLE active";scanJson="[";
    for(int i=0;i<scanCount;i++){BLEAdvertisedDevice d=results->getDevice(i);String name=d.haveName()?String(d.getName().c_str()):"Unnamed";String addr=d.getAddress().toString().c_str();scanRows[i]=name.substring(0,20)+" "+String(d.getRSSI());if(i)scanJson+=",";scanJson+="{\"name\":"+jsonString(name)+",\"address\":"+jsonString(addr)+",\"rssi\":"+String(d.getRSSI())+",\"services\":"+jsonString(d.haveServiceUUID()?String(d.getServiceUUID().toString().c_str()):String(""))+"}";}
    scanJson+="]";showScanRows();
    bleScan->clearResults();if(page==RADIO)dirty=true;
  }
  uint32_t now=millis();
  if(timerOn&&(int32_t)(now-countdownDeadline)>=0){timerOn=false;ringing=true;lastRing=now-1500;lastTimer="";}
  // Chimes run in a separate task so touch and display remain responsive.
  if(ringing&&(uint32_t)(now-lastRing)>=1500){lastRing=now;ringAlert();}
  if((int32_t)(now-nextTouch)>=0) {
    nextTouch=now+8;
    TS_Point p=touch.getPoint();
    if(p.z<400) {
      resetTouchSamples();
      if(!releaseSince)releaseSince=now;
      if(now-releaseSince>=(locked&&unlockPad?16:64)){if(gestureActive&&!cal)finishGesture();gestureActive=false;down=false;}
    } else {
      if(!cal&&gestureActive){float u=p.x/4095.0f,v=p.y/4095.0f;gestureX=constrain((int)lroundf(touchMap.x[0]*u+touchMap.x[1]*v+touchMap.x[2]),0,239);gestureY=constrain((int)lroundf(touchMap.y[0]*u+touchMap.y[1]*v+touchMap.y[2]),0,319);}
      releaseSince=0;
      if(!down && p.x>0 && p.x<4095 && p.y>0 && p.y<4095) {
        sampleMinX=min(sampleMinX,p.x);sampleMaxX=max(sampleMaxX,p.x);
        sampleMinY=min(sampleMinY,p.y);sampleMaxY=max(sampleMaxY,p.y);
        if(sampleMaxX-sampleMinX>140 || sampleMaxY-sampleMinY>140)resetTouchSamples();
        else {
          touchSumX+=p.x;touchSumY+=p.y;++touchSamples;
          if(touchSamples>=(cal?12:3)) {
            float rx=(float)touchSumX/touchSamples,ry=(float)touchSumY/touchSamples;
            down=true;resetTouchSamples();
            if(cal)acceptCalibrationPoint(rx,ry);
            else {
              float u=rx/4095.0f,v=ry/4095.0f;
              int x=lroundf(touchMap.x[0]*u+touchMap.x[1]*v+touchMap.x[2]);
              int y=lroundf(touchMap.y[0]*u+touchMap.y[1]*v+touchMap.y[2]);
              // Reject far-out readings rather than turning them into edge taps.
              if(x>=-8&&x<=247&&y>=-8&&y<=327){gestureActive=true;gestureStartedAt=millis();gestureStartX=gestureX=constrain(x,0,239);gestureStartY=gestureY=constrain(y,0,319);if(locked&&unlockPad){keypadPressHandled=true;tap(gestureX,gestureY);}
                else if(!locked&&page==GAME)gameTouch(gestureX,gestureY);}
            }
          }
        }
      }
    }
  }
  if(!cal){if(!locked && WiFi.status()==WL_CONNECTED && (weatherNext==0 || (int32_t)(now-weatherNext)>=0)){ updateWeather(); weatherNext=millis()+1200000UL; dirty=true; } if(dirty)draw();if((int32_t)(now-nextTick)>=0){nextTick=now+100;dynamicValues();}drawImageRow();}
  delay(1);
}