// // FILE: TM1637.cpp // AUTHOR: Rob Tillaart // DATE: 2019-10-28 // VERSION: 0.3.4 // PURPOSE: TM1637 library for Arduino // URL: https://github.com/RobTillaart/TM1637_RT // NOTE: // on the inexpensive TM1637 boards @wfdudley has used, keyscan // works if you add a 1000 ohm pull-up resistor from DIO to 3.3v // This reduces the rise time of the DIO signal when reading the key info. // If one only uses the pull-up inside the microcontroller, // the rise time is too long for the data to be read reliably. #include "TM1637.h" #define TM1637_ADDR_AUTO 0x40 #define TM1637_READ_KEYSCAN 0x42 #define TM1637_ADDR_FIXED 0x44 #define TM1637_CMD_SET_DATA 0x40 #define TM1637_CMD_SET_ADDR 0xC0 #define TM1637_CMD_DISPLAY 0x88 /*************** --- | | --- | | --- . -01- 20 | | 02 -40- 10 | | 04 -08- .80 */ // PROGMEM ? static uint8_t seg[] = { 0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07, 0x7f, 0x6f, // 0 - 9 0x77, 0x7c, 0x39, 0x5e, 0x79, 0x71, 0x00, 0x40 // A - F, ' ', '-' }; static uint8_t alpha_seg[] = { 0x00, 0x74, 0x10, 0x00, // g, h, i, j, 0x00, 0x38, 0x00, 0x54, // k, l, m, n, 0x5c, 0x00, 0x00, 0x50, // o, p, q, r, 0x00, 0x31, 0x1c, 0x1c, // s, t, u, v, 0x00, 0x00, 0x00, 0x00 // w, x, y, z }; TM1637::TM1637() { _brightness = 0x03; _bitDelay = 10; } // wrapper, will become obsolete 0.4.0. void TM1637::init(uint8_t clockPin, uint8_t dataPin, uint8_t digits) { begin(clockPin, dataPin, digits); } void TM1637::begin(uint8_t clockPin, uint8_t dataPin, uint8_t digits) { _clock = clockPin; _data = dataPin; _digits = digits; pinMode(_clock, OUTPUT); digitalWrite(_clock, HIGH); pinMode(_data, OUTPUT); digitalWrite(_data, HIGH); // TODO: replace _digits by a display enumeration? if (_digits == 4 ) { setDigitOrder(3,2,1,0); } else // (_digits == 6 ) // default { setDigitOrder(3,4,5,0,1,2); } } void TM1637::displayInt(long value) { uint8_t data[8] = { 16, 16, 16, 16, 16, 16, 16, 16}; long v = value; int last = _digits; bool neg = (v < 0); if (neg) { v = -v; last--; data[last] = 17; // minus sign; } for (int i = 0; i < last; i++) { long t = v / 10; data[i] = v - 10 * t; // faster than % v = t; } displayRaw(data, -1); } void TM1637::displayFloat(float value) { uint8_t data[8] = { 16, 16, 16, 16, 16, 16, 16, 16}; float v = value; int dpos = _digits-1; int last = _digits; bool neg = (v < 0); if (neg) { v = -v; dpos--; last--; data[last] = 17; // minus sign; } while (v >= 10) { v /= 10; dpos--; } for (int i = last-1; i > -1; i--) { int d = v; data[i] = d; v -= d; v *= 10; } displayRaw(data, dpos); } void TM1637::displayHex(uint32_t value) { uint8_t data[8] = { 16, 16, 16, 16, 16, 16, 16, 16}; uint32_t v = value; for (int i = 0; i < _digits; i++) { uint32_t t = v / 16; data[i] = v & 0x0F; // faster than % v = t; } displayRaw(data, -1); } void TM1637::displayClear() { uint8_t data[8] = { 16, 16, 16, 16, 16, 16, 16, 16}; displayRaw(data, -1); } void TM1637::setBrightness(uint8_t b) { _brightness = b; if (_brightness > 0x07) _brightness = 0x07; } void TM1637::setDigitOrder(uint8_t a, uint8_t b, uint8_t c, uint8_t d, uint8_t e, uint8_t f, uint8_t g, uint8_t h) { _digitOrder[0] = a; _digitOrder[1] = b; _digitOrder[2] = c; _digitOrder[3] = d; _digitOrder[4] = e; _digitOrder[5] = f; _digitOrder[6] = g; _digitOrder[7] = h; } // Set sign bit on any char to display decimal point void TM1637::displayPChar( char * data ) { start(); writeByte(TM1637_ADDR_AUTO); stop(); start(); writeByte(TM1637_CMD_SET_ADDR); for (int d = _digits-1; d >=0 ; d--) { uint8_t i = _digitOrder[d]; writeByte( asciiTo7Segment(data[i]) ); } stop(); start(); writeByte(TM1637_CMD_DISPLAY | _brightness); stop(); } void TM1637::displayRaw(uint8_t * data, uint8_t pointPos) { uint8_t b = 0; start(); writeByte(TM1637_ADDR_AUTO); stop(); start(); writeByte(TM1637_CMD_SET_ADDR); for (uint8_t d = 0; d < _digits; d++) { uint8_t i = _digitOrder[d]; data[i] &= 0x7f; if (data[i] <= 17) // HEX DIGIT { b = seg[data[i]]; } else if (data[i] <= 37) // ASCII { b = alpha_seg[data[i] - 18]; } // do we need a decimal point if ((i == pointPos) || (data[i] & 0x80)) { b |= 0x80; } writeByte(b); } stop(); start(); writeByte(TM1637_CMD_DISPLAY | _brightness); stop(); } ////////////////////////////////////////////////////// // // PRIVATE // uint8_t TM1637::writeByte(uint8_t data) { // shift out data 8 bits LSB first for (uint8_t i = 8; i > 0; i--) { writeSync(_clock, LOW); writeSync(_data, data & 0x01); writeSync(_clock, HIGH); data >>= 1; } writeSync(_clock, LOW); writeSync(_data, HIGH); writeSync(_clock, HIGH); // get ACKNOWLEDGE pinMode(_data, INPUT); delayMicroseconds(_bitDelay); uint8_t rv = digitalRead(_data); // FORCE OUTPUT LOW pinMode(_data, OUTPUT); digitalWrite(_data, LOW); delayMicroseconds(_bitDelay); return rv; } void TM1637::start() { writeSync(_clock, HIGH); writeSync(_data, HIGH); writeSync(_data, LOW); writeSync(_clock, LOW); } void TM1637::stop() { writeSync(_clock, LOW); writeSync(_data, LOW); writeSync(_clock, HIGH); writeSync(_data, HIGH); } void TM1637::writeSync(uint8_t pin, uint8_t val) { digitalWrite(pin, val); #if defined(ESP32) nanoDelay(2); #endif // other processors may need other "nanoDelay(n)" } // keyscan results are reversed left for right from the data sheet. // here are the values returned by keyscan(): // pin 2 3 4 5 6 7 8 9 // sg1 sg2 sg3 sg4 sg5 sg6 sg7 sg8 // 19 k1 0xf7 0xf6 0xf5 0xf4 0xf3 0xf2 0xf1 0xf0 // 20 k2 0xef 0xee 0xed 0xec 0xeb 0xea 0xe9 0xe8 uint8_t TM1637::keyscan(void) { uint8_t halfDelay = _bitDelay >> 1; uint8_t key; start(); key = 0; writeByte(TM1637_READ_KEYSCAN); // includes the ACK, leaves DATA low pinMode(_data, INPUT_PULLUP); for (uint8_t i = 0; i <= 7; i++) { writeSync(_clock, LOW); delayMicroseconds(halfDelay); writeSync(_clock, HIGH); delayMicroseconds(halfDelay); key >>= 1; key |= (digitalRead(_data)) ? 0x80 : 0x00 ; } writeSync(_clock, LOW); delayMicroseconds(halfDelay); writeSync(_clock, HIGH); // wait for ACK delayMicroseconds(halfDelay); // FORCE OUTPUT LOW pinMode(_data, OUTPUT); digitalWrite(_data, LOW); delayMicroseconds(halfDelay); stop(); return key; } // nanoDelay() makes it possible to go into the sub micron delays. // It is used to lengthen pulses to be minimal 400 ns but not much longer. See datasheet. void TM1637::nanoDelay(uint16_t n) { volatile uint16_t i = n; while (i--); } uint8_t TM1637::asciiTo7Segment ( char c ) { /* -01- 20 | | 02 -40- 10 | | 04 -08- .80 */ // 7+1 Segment patterns for ASCII 0x30-0x5F const uint8_t asciiToSegments[] = { 0x3f,0x06,0x5b,0x4f, 0x66,0x6d,0x7d,0x07, // 0123 4567 0x7f,0x6f,0x09,0x89, 0x58,0x48,0x4c,0xD3, // 89:; <=>? 0x5f,0x77,0x7c,0x39, 0x5E,0x79,0x71,0x3d, // @ABC DEFG 0x76,0x06,0x0E,0x75, 0x38,0x37,0x54,0x5c, // HIJK LMNO 0x73,0x67,0x50,0x6D, 0x78,0x3E,0x1C,0x9c, // PQRS TUVW 0x76,0x6E,0x5B,0x39, 0x52,0x0F,0x23,0x08 // XYZ[ /]^_ }; uint8_t segments = c & 0x80; c &= 0x7f; if ( c >= 0x60 ) c -= 0x20 ; // a-z -> A-Z if ( c == '.' ) segments = 0x80; // decimal point only if ( c == '-' ) segments |= 0x40; // minus sign if ( ( c >= 0x30 ) && ( c <= 0x5F ) ) { segments |= asciiToSegments[ c - 0x30 ]; } return segments; } // -- END OF FILE --