diff options
| -rw-r--r-- | include/arch/atmega2560/driver/dmx.h | 21 | ||||
| -rw-r--r-- | src/arch/atmega2560/driver/dmx.cc | 53 |
2 files changed, 74 insertions, 0 deletions
diff --git a/include/arch/atmega2560/driver/dmx.h b/include/arch/atmega2560/driver/dmx.h new file mode 100644 index 0000000..5550c19 --- /dev/null +++ b/include/arch/atmega2560/driver/dmx.h @@ -0,0 +1,21 @@ +/* + * Copyright 2022 Daniel Friesel + * + * SPDX-License-Identifier: BSD-2-Clause + */ + +class DMX { + private: + DMX(const DMX ©); + + public: + static unsigned char const num_frames = 32; + unsigned char frames[num_frames]; + + DMX() {} + + void setup(); + void write(); +}; + +extern DMX dmx; diff --git a/src/arch/atmega2560/driver/dmx.cc b/src/arch/atmega2560/driver/dmx.cc new file mode 100644 index 0000000..1b21aea --- /dev/null +++ b/src/arch/atmega2560/driver/dmx.cc @@ -0,0 +1,53 @@ +/* + * Copyright 2022 Daniel Friesel + * + * SPDX-License-Identifier: BSD-2-Clause + */ +#include <avr/io.h> +#include "arch.h" +#include "driver/dmx.h" +#include "driver/gpio.h" + +#undef BAUD +#define BAUD 250000UL +#include <util/setbaud.h> + +void DMX::setup() +{ + UBRR3H = UBRRH_VALUE; + UBRR3L = UBRRL_VALUE; + +#if USE_2X + UCSR3A |= _BV(U2X3); +#else + UCSR3A &= ~_BV(U2X3); +#endif + + UCSR3B = _BV(TXEN3); + UCSR3C = _BV(USBS3) | _BV(UCSZ31) | _BV(UCSZ30); // MSB first, 8 data bits, 2 stop bits, no parity +} + +void DMX::write() +{ + // Disable UART for reset and mark signals + UCSR3B &= ~_BV(TXEN3); + gpio.output(GPIO::pj1, 0); + arch.delay_us(88); // break / reset + gpio.output(GPIO::pj1, 1); + arch.delay_us(8); // mark + UCSR3B |= _BV(TXEN3); // causes line to go high + for (uint8_t i = 0; i < 32; i++) { + while (!(UCSR3A & _BV(UDRE3))); + UDR3 = frames[i]; + } + for (uint8_t i = 0; i < 258 - num_frames; i++) { + while (!(UCSR3A & _BV(UDRE3))); + UDR3 = 0; + } + for (uint8_t i = 0; i < 255; i++) { + while (!(UCSR3A & _BV(UDRE3))); + UDR3 = 0; + } +} + +DMX dmx; |