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Car Bluetooth Adapater - ImperiumBT
Introducere
ImperiumBT este un adaptor Bluetooth audio creat pentru casetofoanele din gama VAG (ex: Volkswagen Gamma 5, Audi Concert, Skoda Symphony, etc) care nu dispun de intrare auxiliara.
Proiectul are ca scop modernizarea acestor sisteme audio fara a le modifica structura, prin emularea unui CD changer prin interfata SPI a unui Arduino Uno si prin transmiterea semnalului audio de la un ESP32 cu Bluetooth integrat.
Simulare pentru prezentare
- un amplificator audio in clasa D, alimentat de la o sursa de 24v
- un difuzor JBL de 5inch/ 4Ω
- conexiune analog de la ESP32 catre amplificator
Functionalitati implementate
- Bluetooth Audio (A2DP) – conectare la telefon pentru redare muzica
- Emulare CD changer prin comunicare SPI intre Arduino si casetofon
- Iesire audio analog de la ESP32 la amplificator
- Ecran OLED care afiseaza melodia curenta, conexiunea activa, etc.
- Butoane fizice: Play/Pause, Next, Previous
Functionalitati suplimentare
- Hands-Free:
- microfon atasat la ESP32 pentru apeluri
- butoane pentru preluare / respingere apel
- posibil suport HFP (viitor)
- Extensibilitate:
- cititor microSD pentru redare locala de fisiere audio
- conector jack auxiliar pentru surse audio prin cablu
Hardware Design
Lista de piese
Diagrama Bloc pentru casetofon
Schema electrica
Software Design
<code C> #define DEBUG #define CDC_PREFIX1 0x53 #define CDC_PREFIX2 0x2C #define CDC_END_CMD 0x14 #define CDC_PLAY 0xE4 #define CDC_STOP 0x10 #define CDC_NEXT 0xF8 #define CDC_PREV 0x78 #define CDC_SEEK_FWD 0xD8 #define CDC_SEEK_RWD 0x58 #define CDC_CD1 0x0C #define CDC_CD2 0x8C #define CDC_CD3 0x4C #define CDC_CD4 0xCC #define CDC_CD5 0x2C #define CDC_CD6 0xAC #define CDC_SCAN 0xA0 #define CDC_SFL 0x60 #define CDC_PLAY_NORMAL 0x08 #define MODE_PLAY 0xFF #define MODE_SHFFL 0x55 #define MODE_SCAN 0x00 #include <Arduino.h> #include <SPI.h> volatile long prevMillis = 0; uint8_t cd; uint8_t tr; uint8_t mode; void send_package(uint8_t c0, uint8_t c1, uint8_t c2, uint8_t c3, uint8_t c4, uint8_t c5, uint8_t c6, uint8_t c7) { SPI.beginTransaction(SPISettings(62500, MSBFIRST, SPI_MODE1)); SPI.transfer(c0); delayMicroseconds(874); SPI.transfer(c1); delayMicroseconds(874); SPI.transfer(c2); delayMicroseconds(874); SPI.transfer(c3); delayMicroseconds(874); SPI.transfer(c4); delayMicroseconds(874); SPI.transfer(c5); delayMicroseconds(874); SPI.transfer(c6); delayMicroseconds(874); SPI.transfer(c7); SPI.endTransaction(); } void setup() { cd = 1; tr = 1; mode = MODE_PLAY; #ifdef DEBUG Serial.begin(9600); #endif delay(1000); wait for radio to boot
// Init SPI for Arduino Uno (uses default pins) SPI.begin(); // uses hardware SPI: SCK(13), MISO(12), MOSI(11)
send_package(0x74, 0xBE, 0xFE, 0xFF, 0xFF, 0xFF, 0x8F, 0x7C); // idle delayMicroseconds(10000); send_package(0x34, 0xFF, 0xFE, 0xFE, 0xFE, 0xFF, 0xFA, 0x3C); // load disc delayMicroseconds(100000); send_package(0x74, 0xBE, 0xFE, 0xFF, 0xFF, 0xFF, 0x8F, 0x7C); // idle delayMicroseconds(10000);
#ifdef DEBUG
Serial.println("Sent idle/load/idle commands");
#endif
}
void loop() {
if ((millis() - prevMillis) > 50) {
// disc trk min sec
send_package(0x34, 0xBF ^ cd, 0xFF ^ tr, 0xFF, 0xFF, mode, 0xCF, 0x3C);
prevMillis = millis(); // reset timer
#ifdef DEBUG
Serial.println("Sent packet");
#endif
}
} #define DEBUG #define CDC_PREFIX1 0x53 #define CDC_PREFIX2 0x2C #define CDC_END_CMD 0x14 #define CDC_PLAY 0xE4 #define CDC_STOP 0x10 #define CDC_NEXT 0xF8 #define CDC_PREV 0x78 #define CDC_SEEK_FWD 0xD8 #define CDC_SEEK_RWD 0x58 #define CDC_CD1 0x0C #define CDC_CD2 0x8C #define CDC_CD3 0x4C #define CDC_CD4 0xCC #define CDC_CD5 0x2C #define CDC_CD6 0xAC #define CDC_SCAN 0xA0 #define CDC_SFL 0x60 #define CDC_PLAY_NORMAL 0x08 #define MODE_PLAY 0xFF #define MODE_SHFFL 0x55 #define MODE_SCAN 0x00 #include <Arduino.h> #include <SPI.h> volatile long prevMillis = 0; uint8_t cd; uint8_t tr; uint8_t mode; void send_package(uint8_t c0, uint8_t c1, uint8_t c2, uint8_t c3, uint8_t c4, uint8_t c5, uint8_t c6, uint8_t c7) { SPI.beginTransaction(SPISettings(62500, MSBFIRST, SPI_MODE1)); SPI.transfer(c0); delayMicroseconds(874); SPI.transfer(c1); delayMicroseconds(874); SPI.transfer(c2); delayMicroseconds(874); SPI.transfer(c3); delayMicroseconds(874); SPI.transfer(c4); delayMicroseconds(874); SPI.transfer(c5); delayMicroseconds(874); SPI.transfer(c6); delayMicroseconds(874); SPI.transfer(c7); SPI.endTransaction(); } void setup() { cd = 1; tr = 1; mode = MODE_PLAY; #ifdef DEBUG Serial.begin(9600); #endif delay(1000); wait for radio to boot
// Init SPI for Arduino Uno (uses default pins) SPI.begin(); // uses hardware SPI: SCK(13), MISO(12), MOSI(11)
send_package(0x74, 0xBE, 0xFE, 0xFF, 0xFF, 0xFF, 0x8F, 0x7C); // idle delayMicroseconds(10000); send_package(0x34, 0xFF, 0xFE, 0xFE, 0xFE, 0xFF, 0xFA, 0x3C); // load disc delayMicroseconds(100000); send_package(0x74, 0xBE, 0xFE, 0xFF, 0xFF, 0xFF, 0x8F, 0x7C); // idle delayMicroseconds(10000);
#ifdef DEBUG
Serial.println("Sent idle/load/idle commands");
#endif
}
void loop() {
if ((millis() - prevMillis) > 50) {
// disc trk min sec
send_package(0x34, 0xBF ^ cd, 0xFF ^ tr, 0xFF, 0xFF, mode, 0xCF, 0x3C);
prevMillis = millis(); // reset timer
#ifdef DEBUG
Serial.println("Sent packet");
#endif
}
} </code C>
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