flipperzero-firmware/applications/lf-rfid/em4100.c
coreglitch fd5f694758
[FL-812] Fix emulation timings (#314)
* fix timings
* fix default vendor id to 0
2021-01-29 02:45:32 +03:00

71 lines
1.8 KiB
C

#include <furi.h>
void prepare_data(uint32_t ID, uint32_t VENDOR, uint8_t* data) {
uint8_t value[10];
// vendor rows (4 bit in a row)
value[0] = (VENDOR >> 4) & 0xF;
value[1] = VENDOR & 0xF;
const uint8_t ROW_SIZE = 4;
const uint8_t HEADER_SIZE = 9;
// ID rows (4 bit in a row)
for(int i = 0; i < 8; i++) {
value[i + 2] = (ID >> (28 - i * ROW_SIZE)) & 0xF;
}
for(uint8_t i = 0; i < HEADER_SIZE; i++) {
data[i] = 1; // header
}
for(uint8_t i = 0; i < 10; i++) { // data
for(uint8_t j = 0; j < ROW_SIZE; j++) {
data[HEADER_SIZE + i * (ROW_SIZE + 1) + j] = (value[i] >> ((ROW_SIZE - 1) - j)) & 1;
}
// row parity
data[HEADER_SIZE + i * (ROW_SIZE + 1) + ROW_SIZE] =
(data[HEADER_SIZE + i * (ROW_SIZE + 1) + 0] +
data[HEADER_SIZE + i * (ROW_SIZE + 1) + 1] +
data[HEADER_SIZE + i * (ROW_SIZE + 1) + 2] +
data[HEADER_SIZE + i * (ROW_SIZE + 1) + 3]) %
2;
}
for(uint8_t i = 0; i < ROW_SIZE; i++) { //checksum
uint8_t checksum = 0;
for(uint8_t j = 0; j < 10; j++) {
checksum += data[HEADER_SIZE + i + j * (ROW_SIZE + 1)];
}
data[i + 59] = checksum % 2;
}
data[63] = 0; // stop bit
/*
printf("em data: ");
for(uint8_t i = 0; i < 64; i++) {
printf("%d ", data[i]);
}
printf("\n");
*/
}
void em4100_emulation(uint8_t* data, GpioPin* pin) {
taskENTER_CRITICAL();
gpio_write(pin, true);
for(uint8_t i = 0; i < 8; i++) {
for(uint8_t j = 0; j < 64; j++) {
delay_us(260);
gpio_write(pin, data[j]);
delay_us(260);
gpio_write(pin, !data[j]);
}
}
gpio_write(pin, false);
taskEXIT_CRITICAL();
}