Implement LF RFID emulation (#208)

* migrate code from old repo, not work
* fix emulation
* disable irq handling while RFID emulating
* add testcase

applications/input/input.c

@@ -4,7 +4,7 @@
 #include <flipper_v2.h>
 
 #ifdef APP_NFC
-void st25r3916Isr(void);
+void nfc_isr(void);
 #endif
 
 static volatile bool initialized = false;
@@ -104,7 +104,7 @@ void input_task(void* p) {
 void HAL_GPIO_EXTI_Callback(uint16_t pin) {
 #ifdef APP_NFC
     if(pin == RFID_PULL_Pin) {
-        st25r3916Isr();
+        nfc_isr();
         return;
     }
 #endif

applications/lf-rfid/em4100.c

@@ -0,0 +1,68 @@
+#include "flipper_v2.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(270);
+            gpio_write(pin, data[j]);
+            delay_us(270);
+            gpio_write(pin, !data[j]);
+        }
+    }
+
+    gpio_write(pin, false);
+    taskEXIT_CRITICAL();
+}

applications/lf-rfid/lf-rfid.c

@@ -44,10 +44,22 @@ static void input_callback(InputEvent* input_event, void* ctx) {
 }
 
 extern TIM_HandleTypeDef htim15;
+void em4100_emulation(uint8_t* data, GpioPin* pin);
+void prepare_data(uint32_t ID, uint32_t VENDOR, uint8_t* data);
 
 void lf_rfid_workaround(void* p) {
     osMessageQueueId_t event_queue = osMessageQueueNew(1, sizeof(AppEvent), NULL);
 
+    // create pin
+    GpioPin pull_pin = {.pin = GPIO_PIN_15, .port = GPIOB};
+    // TODO open record
+    GpioPin* pull_pin_record = &pull_pin;
+
+    gpio_init(pull_pin_record, GpioModeOutputPushPull);
+
+    uint8_t emulation_data[64];
+    prepare_data(4378151, 01, emulation_data);
+
     State _state;
     _state.freq_khz = 125;
     _state.on = false;
@@ -73,7 +85,7 @@ void lf_rfid_workaround(void* p) {
 
     AppEvent event;
     while(1) {
-        osStatus_t event_status = osMessageQueueGet(event_queue, &event, NULL, 10000);
+        osStatus_t event_status = osMessageQueueGet(event_queue, &event, NULL, 100);
         State* state = (State*)acquire_mutex_block(&state_mutex);
 
         if(event_status == osOK) {
@@ -81,6 +93,7 @@ void lf_rfid_workaround(void* p) {
                 // press events
                 if(event.value.input.state && event.value.input.input == InputBack) {
                     hal_pwmn_stop(&htim15, TIM_CHANNEL_1); // TODO: move to furiac_onexit
+                    gpio_init(pull_pin_record, GpioModeInput);
                     // TODO remove all widgets create by app
                     widget_enabled_set(widget, false);
                     furiac_exit(NULL);
@@ -111,6 +124,12 @@ void lf_rfid_workaround(void* p) {
         hal_pwmn_set(
             state->on ? 0.5 : 0.0, (float)(state->freq_khz * 1000), &htim15, TIM_CHANNEL_1);
 
+        if(!state->on) {
+            em4100_emulation(emulation_data, pull_pin_record);
+        } else {
+            gpio_write(pull_pin_record, false);
+        }
+
         // common code, for example, force update UI
         widget_update(widget);
 

applications/nfc/nfc.c

@@ -48,6 +48,15 @@ struct Nfc {
 
 #define EXAMPLE_NFCA_DEVICES 5
 
+// TODO replace with pubsub
+static bool isr_enabled = false;
+
+void nfc_isr() {
+    if(isr_enabled) {
+        st25r3916Isr();
+    }
+}
+
 void nfc_worker_task(void* context) {
     Nfc* nfc = context;
     ReturnCode err;
@@ -61,6 +70,8 @@ void nfc_worker_task(void* context) {
 
     nfc->ticker = 0;
 
+    isr_enabled = true;
+
     while(widget_is_enabled(nfc->widget)) {
         rfalFieldOff();
         platformDelay(1000);
@@ -132,6 +143,7 @@ void nfc_worker_task(void* context) {
         widget_update(nfc->widget);
     }
 
+    isr_enabled = false;
     rfalFieldOff();
     rfalLowPowerModeStart();
     nfc->ret = ERR_NONE;