Files
EMS-ESP32/src/emsuart.cpp
2019-05-26 15:56:00 +02:00

285 lines
10 KiB
C++

/*
* emsuart.cpp
*
* The low level UART code for ESP8266 to read and write to the EMS bus via uart
* Paul Derbyshire - https://github.com/proddy/EMS-ESP
*/
#include "emsuart.h"
#include "ems.h"
#include "ets_sys.h"
#include "osapi.h"
#include <Arduino.h>
#include <user_interface.h>
_EMSRxBuf * pEMSRxBuf;
_EMSRxBuf * paEMSRxBuf[EMS_MAXBUFFERS];
uint8_t emsRxBufIdx = 0;
os_event_t recvTaskQueue[EMSUART_recvTaskQueueLen]; // our Rx queue
//
// Main interrupt handler
// Important: do not use ICACHE_FLASH_ATTR !
//
static void emsuart_rx_intr_handler(void * para) {
static uint8_t length;
static uint8_t uart_buffer[EMS_MAXBUFFERSIZE];
// is a new buffer? if so init the thing for a new telegram
if (EMS_Sys_Status.emsRxStatus == EMS_RX_STATUS_IDLE) {
EMS_Sys_Status.emsRxStatus = EMS_RX_STATUS_BUSY; // status set to busy
length = 0;
}
// fill IRQ buffer, by emptying Rx FIFO
if (U0IS & ((1 << UIFF) | (1 << UITO) | (1 << UIBD))) {
while ((USS(EMSUART_UART) >> USRXC) & 0xFF) {
uart_buffer[length++] = USF(EMSUART_UART);
}
// clear Rx FIFO full and Rx FIFO timeout interrupts
U0IC = (1 << UIFF) | (1 << UITO);
}
// BREAK detection = End of EMS data block
if (USIS(EMSUART_UART) & ((1 << UIBD))) {
ETS_UART_INTR_DISABLE(); // disable all interrupts and clear them
U0IC = (1 << UIBD); // INT clear the BREAK detect interrupt
// copy data into transfer buffer
pEMSRxBuf->writePtr = length;
os_memcpy((void *)pEMSRxBuf->buffer, (void *)&uart_buffer, length);
// set the status flag stating BRK has been received and we can start a new package
EMS_Sys_Status.emsRxStatus = EMS_RX_STATUS_IDLE;
// call emsuart_recvTask() at next opportunity
system_os_post(EMSUART_recvTaskPrio, 0, 0);
// re-enable UART interrupts
ETS_UART_INTR_ENABLE();
}
}
/*
* system task triggered on BRK interrupt
* incoming received messages are always asynchronous
* The full buffer is sent to the ems_parseTelegram() function in ems.cpp.
*/
static void ICACHE_FLASH_ATTR emsuart_recvTask(os_event_t * events) {
_EMSRxBuf * pCurrent = pEMSRxBuf;
ems_parseTelegram((uint8_t *)pCurrent->buffer, (pCurrent->writePtr) - 1); // transmit EMS buffer, excluding the BRK
pEMSRxBuf = paEMSRxBuf[++emsRxBufIdx % EMS_MAXBUFFERS]; // next free EMS Receive buffer
}
/*
* flush everything left over in buffer, this clears both rx and tx FIFOs
*/
static inline void ICACHE_FLASH_ATTR emsuart_flush_fifos() {
uint32_t tmp = ((1 << UCRXRST) | (1 << UCTXRST)); // bit mask
USC0(EMSUART_UART) |= (tmp); // set bits
USC0(EMSUART_UART) &= ~(tmp); // clear bits
}
/*
* init UART0 driver
*/
void ICACHE_FLASH_ATTR emsuart_init() {
ETS_UART_INTR_DISABLE();
ETS_UART_INTR_ATTACH(NULL, NULL);
// allocate and preset EMS Receive buffers
for (int i = 0; i < EMS_MAXBUFFERS; i++) {
_EMSRxBuf * p = (_EMSRxBuf *)malloc(sizeof(_EMSRxBuf));
paEMSRxBuf[i] = p;
}
pEMSRxBuf = paEMSRxBuf[0]; // preset EMS Rx Buffer
// pin settings
PIN_PULLUP_DIS(PERIPHS_IO_MUX_U0TXD_U);
PIN_FUNC_SELECT(PERIPHS_IO_MUX_U0TXD_U, FUNC_U0TXD);
PIN_PULLUP_DIS(PERIPHS_IO_MUX_U0RXD_U);
PIN_FUNC_SELECT(PERIPHS_IO_MUX_U0RXD_U, FUNC_U0RXD);
// set 9600, 8 bits, no parity check, 1 stop bit
USD(EMSUART_UART) = (UART_CLK_FREQ / EMSUART_BAUD);
USC0(EMSUART_UART) = EMSUART_CONFIG; // 8N1
emsuart_flush_fifos();
// conf1 params
// UCTOE = RX TimeOut enable (default is 1)
// UCTOT = RX TimeOut Threshold (7bit) = want this when no more data after 2 characters. (default is 2)
// UCFFT = RX FIFO Full Threshold (7 bit) = want this to be 31 for 32 bytes of buffer. (default was 127).
// see https://www.espressif.com/sites/default/files/documentation/esp8266-technical_reference_en.pdf
USC1(EMSUART_UART) = 0; // reset config first
USC1(EMSUART_UART) = (EMS_MAX_TELEGRAM_LENGTH << UCFFT) | (0x02 << UCTOT) | (1 << UCTOE); // enable interupts
// set interrupts for triggers
USIC(EMSUART_UART) = 0xFFFF; // clear all interupts
USIE(EMSUART_UART) = 0; // disable all interrupts
// enable rx break, fifo full and timeout.
// not frame error UIFR (because they are too frequent) or overflow UIOF because our buffer is only max 32 bytes
USIE(EMSUART_UART) = (1 << UIBD) | (1 << UIFF) | (1 << UITO);
// set up interrupt callbacks for Rx
system_os_task(emsuart_recvTask, EMSUART_recvTaskPrio, recvTaskQueue, EMSUART_recvTaskQueueLen);
// disable esp debug which will go to Tx and mess up the line
system_set_os_print(0); // https://github.com/espruino/Espruino/issues/655
// swap Rx and Tx pins to use GPIO13 (D7) and GPIO15 (D8) respectively
#ifndef NO_UART_SWAP
system_uart_swap();
#endif
ETS_UART_INTR_ATTACH(emsuart_rx_intr_handler, NULL);
ETS_UART_INTR_ENABLE();
}
/*
* stop UART0 driver
* This is called prior to an OTA upload and also before a save to SPIFFS to prevent conflicts
*/
void ICACHE_FLASH_ATTR emsuart_stop() {
ETS_UART_INTR_DISABLE();
}
/*
* re-start UART0 driver
*/
void ICACHE_FLASH_ATTR emsuart_start() {
ETS_UART_INTR_ENABLE();
}
/*
* Send a BRK signal
* Which is a 11-bit set of zero's (11 cycles)
*/
void ICACHE_FLASH_ATTR emsuart_tx_brk() {
uint32_t tmp;
// must make sure Tx FIFO is empty
while (((USS(EMSUART_UART) >> USTXC) & 0xFF) != 0)
;
tmp = ((1 << UCRXRST) | (1 << UCTXRST)); // bit mask
USC0(EMSUART_UART) |= (tmp); // set bits
USC0(EMSUART_UART) &= ~(tmp); // clear bits
// To create a 11-bit <BRK> we set TXD_BRK bit so the break signal will
// automatically be sent when the tx fifo is empty
tmp = (1 << UCBRK);
USC0(EMSUART_UART) |= (tmp); // set bit
if (EMS_Sys_Status.emsTxMode <= 2) {
delayMicroseconds(EMSUART_TX_BRK_WAIT); // classic mode
} else if (EMS_Sys_Status.emsTxMode == 3) {
delayMicroseconds(EMSUART_TX_WAIT_BRK - EMSUART_TX_LAG); // 1144 (11 Bits)
}
USC0(EMSUART_UART) &= ~(tmp); // clear bit
}
/*
* set loopback mode and clear Tx/Rx FIFO
*/
static inline void ICACHE_FLASH_ATTR emsuart_loopback(bool enable) {
if (enable)
USC0(EMSUART_UART) |= (1 << UCLBE); // enable loopback
else
USC0(EMSUART_UART) &= ~(1 << UCLBE); // disable loopback
}
/*
* Send to Tx, ending with a <BRK>
*/
void ICACHE_FLASH_ATTR emsuart_tx_buffer(uint8_t * buf, uint8_t len) {
if (EMS_Sys_Status.emsTxMode == 0) { // Classic logic
for (uint8_t i = 0; i < len; i++) {
USF(EMSUART_UART) = buf[i];
}
emsuart_tx_brk(); // send <BRK>
} else if (EMS_Sys_Status.emsTxMode == 1) { // With extra tx delay for EMS+
for (uint8_t i = 0; i < len; i++) {
USF(EMSUART_UART) = buf[i];
delayMicroseconds(EMSUART_TX_BRK_WAIT); // https://github.com/proddy/EMS-ESP/issues/23#
}
emsuart_tx_brk(); // send <BRK>
} else if (EMS_Sys_Status.emsTxMode == 3) { // Junkers logic by @philrich
for (uint8_t i = 0; i < len; i++) {
USF(EMSUART_UART) = buf[i];
// just to be safe wait for tx fifo empty (needed?)
while (((USS(EMSUART_UART) >> USTXC) & 0xff) != 0)
;
// wait until bits are sent on wire
delayMicroseconds(EMSUART_TX_WAIT_BYTE - EMSUART_TX_LAG + EMSUART_TX_WAIT_GAP);
}
emsuart_tx_brk(); // send <BRK>
} else if (EMS_Sys_Status.emsTxMode == 2) { // smart Tx - take two - https://github.com/proddy/EMS-ESP/issues/103 by @susisstrolch
/*
* we emit the whole telegram, with Rx interrupt disabled, collecting busmaster response in FIFO.
* after sending the last char we poll the Rx status until either
* - size(Rx FIFO) == size(Tx-Telegram)
* - <BRK> is detected
* At end of receive we re-enable Rx-INT and send a Tx-BRK in loopback mode.
*/
ETS_UART_INTR_DISABLE(); // disable rx interrupt
// clear Rx status register - https://github.com/proddy/EMS-ESP/issues/103#issuecomment-495605798
USC0(EMSUART_UART) |= (1 << UCRXRST); // reset uart rx fifo
emsuart_flush_fifos();
// throw out the telegram...
for (uint8_t i = 0; i < len; i++) {
USF(EMSUART_UART) = buf[i]; // send each Tx byte
}
// wait until we received sizeof(telegram) or RxBRK (== collision detect)
while ((((USS(EMSUART_UART) >> USRXC) & 0xFF) < len) || (USIS(EMSUART_UART) & (1 << UIBD))) {
delayMicroseconds(11 * EMSUART_BIT_TIME); // burn CPU cycles...
}
// we got the whole telegram in Rx buffer
// on Rx-BRK (bus collision), we simply enable Rx and leave
// otherwise, we send the final Tx-BRK in loopback and enable Rx-INT.
// worst case, we'll see an additional Rx-BRK...
if (!(USIS(EMSUART_UART) & (1 << UIBD))) {
// no bus collision - send terminating BRK signal
emsuart_loopback(true);
USC0(EMSUART_UART) |= (1 << UCBRK); // set <BRK>
// wait until BRK detected...
while (!(USIS(EMSUART_UART) & (1 << UIBD))) {
delayMicroseconds(EMSUART_BIT_TIME / 8); // ~13µs
}
USC0(EMSUART_UART) &= ~(1 << UCBRK); // clear <BRK>
USIC(EMSUART_UART) = (1 << UIBD); // clear BRK detect IRQ
emsuart_loopback(false); // disable loopback mode
}
emsuart_flush_fifos(); // flush Rx buffer to be sure
ETS_UART_INTR_ENABLE(); // receive anything from FIFO...
}
}
/*
* Send the Poll (our own ID) to Tx as a single byte and end with a <BRK>
*/
void ICACHE_FLASH_ATTR emsuart_tx_poll() {
static uint8_t buf[1];
if (EMS_Sys_Status.emsReverse) {
buf[0] = {EMS_ID_ME | 0x80};
} else {
buf[0] = {EMS_ID_ME};
}
emsuart_tx_buffer(buf, 1);
}