uvk5cec/app/aircopy.c

/* Copyright 2023 Dual Tachyon
 * https://github.com/DualTachyon
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *     Unless required by applicable law or agreed to in writing, software
 *     distributed under the License is distributed on an "AS IS" BASIS,
 *     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *     See the License for the specific language governing permissions and
 *     limitations under the License.
 */

#ifdef ENABLE_AIRCOPY

#include "app/aircopy.h"
#include "audio.h"
#include "driver/bk4819.h"
#include "driver/crc.h"
#include "driver/eeprom.h"
#include "frequencies.h"
#include "misc.h"
#include "radio.h"
#include "ui/helper.h"
#include "ui/inputbox.h"
#include "ui/ui.h"

static const uint16_t Obfuscation[8] = { 0x6C16, 0xE614, 0x912E, 0x400D, 0x3521, 0x40D5, 0x0313, 0x80E9 };

AIRCOPY_State_t gAircopyState;
uint16_t gAirCopyBlockNumber;
uint16_t gErrorsDuringAirCopy;
uint8_t gAirCopyIsSendMode;

uint16_t g_FSK_Buffer[36];

bool AIRCOPY_SendMessage(void)
{
	static uint8_t gAircopySendCountdown = 1;

	if (gAircopyState != AIRCOPY_TRANSFER) {
		return 1;
	}

	if (--gAircopySendCountdown) {
		return 1;
	}

	g_FSK_Buffer[1] = (gAirCopyBlockNumber & 0x3FF) << 6;

	EEPROM_ReadBuffer(g_FSK_Buffer[1], &g_FSK_Buffer[2], 64);

	g_FSK_Buffer[34] = CRC_Calculate(&g_FSK_Buffer[1], 2 + 64);

	for (unsigned int i = 0; i < 34; i++) {
		g_FSK_Buffer[i + 1] ^= Obfuscation[i % 8];
	}

	if (++gAirCopyBlockNumber >= 0x78) {
		gAircopyState = AIRCOPY_COMPLETE;
	}

	RADIO_SetTxParameters();

	BK4819_SendFSKData(g_FSK_Buffer);
	BK4819_SetupPowerAmplifier(0, 0);
	BK4819_ToggleGpioOut(BK4819_GPIO1_PIN29_PA_ENABLE, false);

	gAircopySendCountdown = 30;

	return 0;
}

void AIRCOPY_StorePacket(void)
{
	if (gFSKWriteIndex < 36) {
		return;
	}

	gFSKWriteIndex = 0;
	gUpdateDisplay = true;
	uint16_t Status = BK4819_ReadRegister(BK4819_REG_0B);
	BK4819_PrepareFSKReceive();

	// Doc says bit 4 should be 1 = CRC OK, 0 = CRC FAIL, but original firmware checks for FAIL.

	if ((Status & 0x0010U) != 0 || g_FSK_Buffer[0] != 0xABCD || g_FSK_Buffer[35] != 0xDCBA) {
		gErrorsDuringAirCopy++;
		return;
	}

	for (unsigned int i = 0; i < 34; i++) {
		g_FSK_Buffer[i + 1] ^= Obfuscation[i % 8];
	}

	uint16_t CRC = CRC_Calculate(&g_FSK_Buffer[1], 2 + 64);
	if (g_FSK_Buffer[34] != CRC) {
		gErrorsDuringAirCopy++;
		return;
	}

	uint16_t Offset = g_FSK_Buffer[1];

	if (Offset >= 0x1E00) {
		gErrorsDuringAirCopy++;
		return;
	}

	const uint16_t *pData = &g_FSK_Buffer[2];
	for (unsigned int i = 0; i < 8; i++) {
		EEPROM_WriteBuffer(Offset, pData);
		pData += 4;
		Offset += 8;
	}

	if (Offset == 0x1E00) {
		gAircopyState = AIRCOPY_COMPLETE;
	}

	gAirCopyBlockNumber++;
}

static void AIRCOPY_Key_DIGITS(KEY_Code_t Key, bool bKeyPressed, bool bKeyHeld)
{
	if (bKeyHeld || !bKeyPressed) {
		return;
	}

	INPUTBOX_Append(Key);

	gRequestDisplayScreen = DISPLAY_AIRCOPY;

	if (gInputBoxIndex < 6) {
#ifdef ENABLE_VOICE
		gAnotherVoiceID = (VOICE_ID_t)Key;
#endif
		return;
	}

	gInputBoxIndex = 0;
	uint32_t Frequency = StrToUL(INPUTBOX_GetAscii()) * 100;

	for (unsigned int i = 0; i < BAND_N_ELEM; i++) {
		if (Frequency < frequencyBandTable[i].lower || Frequency >= frequencyBandTable[i].upper) {
			continue;
		}

		if (TX_freq_check(Frequency)) {
			continue;
		}

#ifdef ENABLE_VOICE
		gAnotherVoiceID = (VOICE_ID_t)Key;
#endif

		Frequency = FREQUENCY_RoundToStep(Frequency, gRxVfo->StepFrequency);
		gRxVfo->Band = i;
		gRxVfo->freq_config_RX.Frequency = Frequency;
		gRxVfo->freq_config_TX.Frequency = Frequency;
		RADIO_ConfigureSquelchAndOutputPower(gRxVfo);
		gCurrentVfo = gRxVfo;
		RADIO_SetupRegisters(true);
		BK4819_SetupAircopy();
		BK4819_ResetFSK();
		return;
	}

	gRequestDisplayScreen = DISPLAY_AIRCOPY;
}

static void AIRCOPY_Key_EXIT(bool bKeyPressed, bool bKeyHeld)
{
	if (bKeyHeld || !bKeyPressed) {
		return;
	}

	if (gInputBoxIndex == 0) {
		gFSKWriteIndex = 0;
		gAirCopyBlockNumber = 0;
		gInputBoxIndex = 0;
		gErrorsDuringAirCopy = 0;
		gAirCopyIsSendMode = 0;

		BK4819_PrepareFSKReceive();

		gAircopyState = AIRCOPY_TRANSFER;
	} else {
		gInputBox[--gInputBoxIndex] = 10;
	}

	gRequestDisplayScreen = DISPLAY_AIRCOPY;
}

static void AIRCOPY_Key_MENU(bool bKeyPressed, bool bKeyHeld)
{
	if (bKeyHeld || !bKeyPressed) {
		return;
	}

	gFSKWriteIndex = 0;
	gAirCopyBlockNumber = 0;
	gInputBoxIndex = 0;
	gAirCopyIsSendMode = 1;
	g_FSK_Buffer[0] = 0xABCD;
	g_FSK_Buffer[1] = 0;
	g_FSK_Buffer[35] = 0xDCBA;

	GUI_DisplayScreen();

	gAircopyState = AIRCOPY_TRANSFER;
}

void AIRCOPY_ProcessKeys(KEY_Code_t Key, bool bKeyPressed, bool bKeyHeld)
{
	switch (Key) {
	case KEY_0:
	case KEY_1:
	case KEY_2:
	case KEY_3:
	case KEY_4:
	case KEY_5:
	case KEY_6:
	case KEY_7:
	case KEY_8:
	case KEY_9:
		AIRCOPY_Key_DIGITS(Key, bKeyPressed, bKeyHeld);
		break;
	case KEY_MENU:
		AIRCOPY_Key_MENU(bKeyPressed, bKeyHeld);
		break;
	case KEY_EXIT:
		AIRCOPY_Key_EXIT(bKeyPressed, bKeyHeld);
		break;
	default:
		break;
	}
}

#endif