手工打造的逻辑分析探头

/************************************************************************** ATtiny1614 Logic Probe
 Schematic & PCB at https://www.hackster.io/john-bradnam/contact-digital-thermometer-ed18d2  2021-08-10 John Bradnam (jbrad2089@gmail.com)   Create program for ATtiny1614
 -------------------------------------------------------------------------- Arduino IDE: --------------------------------------------------------------------------  BOARD: ATtiny1614/1604/814/804/414/404/214/204  Chip: ATtiny1614  Clock Speed: 20MHz  millis()/micros(): "Enabled (default timer)"  Programmer: jtag2updi (megaTinyCore)
  ATTiny1614 Pins mapped to Ardunio Pins               +--------+          VCC + 1   14 + GND  (SS)  0 PA4 + 2   13 + PA3 10 (SCK)        1 PA5 + 3   12 + PA2 9  (MISO)  (DAC) 2 PA6 + 4   11 + PA1 8  (MOSI)        3 PA7 + 5   10 + PA0 11 (UPDI)  (RXD) 4 PB3 + 6    9 + PB0 7  (SCL)  (TXD) 5 PB2 + 7    8 + PB1 6  (SDA)              +--------+   **************************************************************************/
//Debug mode will use the TX pin to send serial messages. As this is also used//for Segment A, the display is disabled when DEBUG mode is enabled//#define DEBUG 
//Display Pins#define A_PIN 5     //PB2#define B_PIN 4     //PB3#define C_PIN 3     //PA7#define D_PIN 0     //PA4#define EF_PIN 1    //PA5#define G_PIN 2     //PA6
//Inputs#define VIN_PIN 9   //PA2#define PROBE_PIN 8 //PA1#define MODE_PIN 10 //PA3
#define ADC_PROBE ADC_MUXPOS_AIN1_gc#define ADC_VIN ADC_MUXPOS_AIN2_gc

//Outputs#define SPKR_PIN 6  //PB1
//Frequency for different states#define VDD_TONE 1760#define HIGH_TONE 880#define LOW_TONE 220#define GND_TONE 110#define BTN_TONE 440
//Pin and mask mapping tabletypedef struct {  int8_t pin;  int8_t mask;} SEG;
#define SEG_COUNT 6SEG segments[] = {  {A_PIN,  B00000001},  {B_PIN,  B00000010},  {C_PIN,  B00000100},  {D_PIN,  B00001000},  {EF_PIN, B00010000},  {G_PIN,  B00100000}};
//Character set#define CHAR_COUNT 10#define CHAR_SPACE 0#define CHAR_VDD 1#define CHAR_HIGH 2#define CHAR_FLOAT 3#define CHAR_LOW 4#define CHAR_GND 5#define CHAR_PULSE 6#define CHAR_CMOS 7#define CHAR_TTL 8#define CHAR_LS 9
uint8_t charset[] = {  B00000000,  //CHAR_SPACE  B00000001,  //CHAR_VDD  B00000110,  //CHAR_HIGH  B00100000,  //CHAR_FLOAT  B00011111,  //CHAR_LOW  B00001000,  //CHAR_GND  B00110011,  //CHAR_PULSE  B00011001,  //CHAR_CMOS  B00111000,  //CHAR_TTL  B00011000   //CHAR_LS};
char debugset[] = {  ' ',  //CHAR_SPACE  '+',  //CHAR_VDD  '1',  //CHAR_HIGH  '?',  //CHAR_FLOAT  '0',  //CHAR_LOW  '-',  //CHAR_GND  'P',  //CHAR_PULSE  'C',  //CHAR_CMOS  'T',  //CHAR_TTL  'L'   //CHAR_LS};
typedef struct {  float low;    //Maximum voltage a LOW state can be (fixed voltage)  float high;   //Minumum voltage a HIGH state can be as a percentage of VDD  uint8_t chr;  //Character to display for this family} FAMILY;
//This table defines the voltage levels for each family that the probe can measure#define NUMBER_OF_FAMILIES 3FAMILY families[NUMBER_OF_FAMILIES] = {  {0.8,80,CHAR_CMOS},   //CMOS family with tones  {0.4,48,CHAR_TTL},    //0.4, 2.4 (1987 - National LS S TTL Logic Databook)  {0.5,54,CHAR_LS}      //0.5, 2.7 (1987 - National LS S TTL Logic Databook)};
enum STATES { STATE_UNKNOWN, STATE_VDD, STATE_HIGH, STATE_FLOAT, STATE_LOW, STATE_GND, STATE_PULSE };
#define PULSE_PERIOD 100            //Maximum time between state changes to be detected as a pulse (1/2 the period => 5Hz)
uint8_t activeFamily = 0;           //Current chip family being testedSTATES lastState = STATE_UNKNOWN;   //Last state measuredSTATES activeState = STATE_UNKNOWN; //Current state at probefloat supplyVoltage = 0;            //VDD from 3V3 regulatorfloat probeVoltage = 0;             //Last reading from probefloat vinVoltage = 0;               //Last reading from VINlong pulseTimeout = 0;              //Timer used to measure pulsesbool waitingOnChange = false;       //Enabled when waiting on pulseTimeoutbool soundEnabled = false;          //Whether tones are played for the states
//-------------------------------------------------------------------------// Initialise Hardwarevoid setup(void){  for (int i = 0; i < SEG_COUNT; i++)  {    pinMode(segments[i].pin, OUTPUT);    digitalWrite(segments[i].pin, LOW);  }
  #ifdef DEBUG    Serial.begin(115200);  #endif
  pinMode(VIN_PIN, INPUT);  pinMode(PROBE_PIN, INPUT);  pinMode(MODE_PIN, INPUT_PULLUP);  pinMode(SPKR_PIN, OUTPUT);
  //Setup ADC  VREF.CTRLA = VREF_ADC0REFSEL_1V1_gc;  ADC0.CTRLC = ADC_REFSEL_VDDREF_gc | ADC_PRESC_DIV256_gc; // 78kHz clock  ADC0.CTRLA = ADC_ENABLE_bm;                              // Single, 10-bit
  measureSupplyVoltage();}
//--------------------------------------------------------------------// Main program loopvoid loop(void){  if (buttonPressed())  {    activeFamily++;    if (activeFamily == NUMBER_OF_FAMILIES)    {      activeFamily = 0;      soundEnabled = !soundEnabled;   //Turn/off audio    }    showChar(families[activeFamily].chr);    noTone(SPKR_PIN);    if (soundEnabled)    {      tone(SPKR_PIN, BTN_TONE);    }    waitForButtonRelease();    noTone(SPKR_PIN);
    //Force an update    waitingOnChange = false;    lastState = STATE_UNKNOWN;  }  testProbe();}
//--------------------------------------------------------------------// Test if button pressedbool buttonPressed(){  bool result = false;  if (digitalRead(MODE_PIN) == LOW)  {    delay(10);    //Debounce    return (digitalRead(MODE_PIN) == LOW);  }  return result;}
//--------------------------------------------------------------------// Wait until the button is releasedvoid waitForButtonRelease(){  while (digitalRead(MODE_PIN) == LOW) ;}
//--------------------------------------------------------------------// Measure the voltages and dislay the results if changedvoid testProbe(){    //Voltages are feed through divide by 4 resistor voltage converter   //so they need to multiplied by 4.   probeVoltage = measureVoltage(ADC_PROBE) * 4;  vinVoltage = measureVoltage(ADC_VIN) * 4;
  //Calculate HIGH and VDD thresholds from VIN voltage  float vdd = vinVoltage - 0.1;  float high = families[activeFamily].high * vinVoltage / 100;  bool pulse = false;    //Workout state  if (probeVoltage < 0.1)  {    activeState = STATE_GND;  }  else if (probeVoltage <= families[activeFamily].low)  {    activeState = STATE_LOW;  }  else if (probeVoltage < high)  {    activeState = STATE_FLOAT;  }  else if (probeVoltage <= vdd)  {    activeState = STATE_HIGH;  }  else  {    activeState = STATE_VDD;  }
    if (activeState != lastState) //Only do something if state changes  {    #ifdef DEBUG      Serial.println("p=" + String(probeVoltage) + ", vin=" + String(vinVoltage) + ", vdd=" + String(supplyVoltage));      delay(200);    #endif        if ((activeState == STATE_HIGH) ^ (lastState == STATE_HIGH)) //Change in state from either LOW to HIGH or HIGH to LOW    {      pulse = (waitingOnChange && millis() < pulseTimeout); //If state change within PULSE_PERIOD signal it as a pulse      pulseTimeout = millis() + PULSE_PERIOD;               //Set next timeout      waitingOnChange = true;                               //and signal we are waiting on a state change    }    else    {      //This isn't a pulse      waitingOnChange = false;      pulse = false;    }
    //Turn off any sound from the last state    noTone(SPKR_PIN);
    //Show the result    int chr = (pulse) ? CHAR_PULSE : (uint8_t)activeState;    showChar(chr);
    if (soundEnabled) //Play sound if enabled    {      switch(chr)      {        case CHAR_VDD: tone(SPKR_PIN, VDD_TONE); break;        case CHAR_HIGH: tone(SPKR_PIN, HIGH_TONE); break;        case CHAR_LOW: tone(SPKR_PIN, LOW_TONE); break;        case CHAR_GND: tone(SPKR_PIN, GND_TONE); break;      }    }
    //Record last state    lastState = activeState;  }}
//--------------------------------------------------------------------// Display character on 7 segment display// chr - character to show (0 <= chr < CHAR_COUNT)void showChar(uint8_t chr){  if (chr < CHAR_COUNT)  {    #ifdef DEBUG      Serial.println(debugset[chr]);    #else      uint8_t mask = charset[chr];      for (int i = 0; i < SEG_COUNT; i++)      {        digitalWrite(segments[i].pin, (mask & segments[i].mask) ? HIGH : LOW);      }    #endif  }    }
//--------------------------------------------------------------------------// Measure supply voltage// Source: David Johnson-Davies - www.technoblogy.com - 13th April 2021void measureSupplyVoltage() {  ADC0.MUXPOS = ADC_MUXPOS_INTREF_gc;                  // Measure INTREF  ADC0.COMMAND = ADC_STCONV_bm;                        // Start conversion  while (ADC0.COMMAND & ADC_STCONV_bm);                // Wait for completion  uint16_t adc_reading = ADC0.RES;                     // ADC conversion result  supplyVoltage = 1126.4 / adc_reading;}
//--------------------------------------------------------------------------// Measure voltage of a given pin// adcMux - ADC_Ax constant for the pin to measurefloat measureVoltage(uint8_t adcMux) {  ADC0.MUXPOS = adcMux;                                // Measure Analog pin  ADC0.COMMAND = ADC_STCONV_bm;                        // Start conversion  while (ADC0.COMMAND & ADC_STCONV_bm);                // Wait for completion  uint16_t adc_reading = ADC0.RES;                     // ADC conversion result  return supplyVoltage * adc_reading / 1024;}