// Sample program demonstrating the use of the Big Integer Library. // Standard libraries #include #include // `BigIntegerLibrary.hh' includes all of the library headers. #include "BigIntegerLibrary.hh" int main() { /* The library throws `const char *' error messages when things go * wrong. It's a good idea to catch them using a `try' block like this * one. Your C++ compiler might need a command-line option to compile * code that uses exceptions. */ try { BigInteger a; // a is 0 int b = 535; /* Any primitive integer can be converted implicitly to a * BigInteger. */ a = b; /* The reverse conversion requires a method call (implicit * conversions were previously supported but caused trouble). * If a were too big for an int, the library would throw an * exception. */ b = a.toInt(); BigInteger c(a); // Copy a BigInteger. // The int literal is converted to a BigInteger. BigInteger d(-314159265); /* This won't compile (at least on 32-bit machines) because the * number is too big to be a primitive integer literal, and * there's no such thing as a BigInteger literal. */ //BigInteger e(3141592653589793238462643383279); // Instead you can convert the number from a string. std::string s("3141592653589793238462643383279"); BigInteger f = stringToBigInteger(s); // You can convert the other way too. std::string s2 = bigIntegerToString(f); // f is implicitly stringified and sent to std::cout. std::cout << f << std::endl; /* Let's do some math! The library overloads most of the * mathematical operators (including assignment operators) to * work on BigIntegers. There are also ``copy-less'' * operations; see `BigUnsigned.hh' for details. */ // Arithmetic operators BigInteger g(314159), h(265); std::cout << (g + h) << '\n' << (g - h) << '\n' << (g * h) << '\n' << (g / h) << '\n' << (g % h) << std::endl; // Bitwise operators BigUnsigned i(0xFF0000FF), j(0x0000FFFF); // The library's << operator recognizes base flags. std::cout.flags(std::ios::hex | std::ios::showbase); std::cout << (i & j) << '\n' << (i | j) << '\n' << (i ^ j) << '\n' // Shift distances are ordinary unsigned ints. << (j << 21) << '\n' << (j >> 10) << '\n'; std::cout.flags(std::ios::dec); // Let's do some heavy lifting and calculate powers of 314. int maxPower = 10; BigUnsigned x(1), big314(314); for (int power = 0; power <= maxPower; power++) { std::cout << "314^" << power << " = " << x << std::endl; x *= big314; // A BigInteger assignment operator } // Some big-integer algorithms (albeit on small integers). std::cout << gcd(BigUnsigned(60), 72) << '\n' << modinv(BigUnsigned(7), 11) << '\n' << modexp(BigUnsigned(314), 159, 2653) << std::endl; // Add your own code here to experiment with the library. } catch(char const* err) { std::cout << "The library threw an exception:\n" << err << std::endl; } return 0; } /* The original sample program produces this output: 3141592653589793238462643383279 314424 313894 83252135 1185 134 0xFF 0xFF00FFFF 0xFF00FF00 0x1FFFE00000 0x3F 314^0 = 1 314^1 = 314 314^2 = 98596 314^3 = 30959144 314^4 = 9721171216 314^5 = 3052447761824 314^6 = 958468597212736 314^7 = 300959139524799104 314^8 = 94501169810786918656 314^9 = 29673367320587092457984 314^10 = 9317437338664347031806976 12 8 1931 */ 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105

# I2C Master Driver

The I2C Master drivers used in QMK have a set of common functions to allow portability between MCUs.

## Available functions

|Function                                                                                                          |Description                                                                                                                                                                  |
|------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|`void i2c_init(void);`                                                                                            |Initializes the I2C driver. This function should be called once before any transaction is initiated.                                                                         |
|`uint8_t i2c_start(uint8_t address);`                                                                             |Starts an I2C transaction. Address is the 7-bit slave address without the direction bit.                                                                                     |
|`uint8_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout);`                        |Transmit data over I2C. Address is the 7-bit slave address without the direction. Returns status of transaction.                                                             |
|`uint8_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout);`                         |Receive data over I2C. Address is the 7-bit slave address without the direction. Saves number of bytes specified by `length` in `data` array. Returns status of transaction. |
|`uint8_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout);`       |Same as the `i2c_transmit` function but `regaddr` sets where in the slave the data will be written.                                                                          |
|`uint8_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout);`        |Same as the `i2c_receive` function but `regaddr` sets from where in the slave the data will be read.                                                                         |
|`uint8_t i2c_stop(void);`                                                                                         |Ends an I2C transaction.                                                                                                                                                     |