uv-k5-firmware-custom/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];

void AIRCOPY_SendMessage(void)
{
	unsigned int i;

	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 (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_GPIO5_PIN1, false);

	gAircopySendCountdown = 30;
}

void AIRCOPY_StorePacket(void)
{
	uint16_t Status;

	if (gFSKWriteIndex < 36)
		return;

	gFSKWriteIndex = 0;
	gUpdateDisplay = true;
	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)
	{
		uint16_t     CRC;
		unsigned int i;

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

		CRC = CRC_Calculate(&g_FSK_Buffer[1], 2 + 64);
		if (g_FSK_Buffer[34] == CRC)
		{
			const uint16_t *pData;
			uint16_t        Offset;

			Offset = g_FSK_Buffer[1];
			if (Offset < 0x1E00)
			{
				pData = &g_FSK_Buffer[2];
				for (i = 0; i < 8; i++)
				{
					EEPROM_WriteBuffer(Offset, pData);
					pData  += 4;
					Offset += 8;
				}
				
				if (Offset == 0x1E00)
					gAircopyState = AIRCOPY_COMPLETE;

				gAirCopyBlockNumber++;

				return;
			}
		}
	}
	gErrorsDuringAirCopy++;
}

static void AIRCOPY_Key_DIGITS(KEY_Code_t Key, bool bKeyPressed, bool bKeyHeld)
{
	if (!bKeyHeld && bKeyPressed)
	{
		uint32_t      Frequency;
		unsigned int  i;

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

		gInputBoxIndex = 0;

		NUMBER_Get(gInputBox, &Frequency);

		for (i = 0; i < 7; i++)
		{
			if (Frequency >= LowerLimitFrequencyBandTable[i] && Frequency <= UpperLimitFrequencyBandTable[i])
			{
				#ifdef ENABLE_VOICE
					gAnotherVoiceID        = (VOICE_ID_t)Key;
				#endif
				gRxVfo->Band               = i;
				Frequency                 += 75;
				Frequency                  = FREQUENCY_FloorToStep(Frequency, gRxVfo->StepFrequency, 0);
				gRxVfo->ConfigRX.Frequency = Frequency;
				gRxVfo->ConfigTX.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)
	{
		if (gInputBoxIndex == 0)
		{
			gFSKWriteIndex       = 0;
			gAirCopyBlockNumber  = 0;
			gErrorsDuringAirCopy = 0;
			gInputBoxIndex       = 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)
	{
		gFSKWriteIndex      = 0;
		gAirCopyBlockNumber = 0;
		gInputBoxIndex      = 0;
		gAirCopyIsSendMode  = 1;
		g_FSK_Buffer[0]     = 0xABCD;
		g_FSK_Buffer[1]     = 0;
		g_FSK_Buffer[35]    = 0xDCBA;

		AIRCOPY_SendMessage();
		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