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This is a SLIP interface for the STM32F446RE Nucleo Board. It is designed to work specifically with the esp-link software for the ESP8266. The program is an example of a rest command.
STMClient.cpp
- Committer:
- ShaneKirkbride
- Date:
- 2016-08-17
- Revision:
- 8:6a3b7c5d9ba7
- Parent:
- 4:31bed73a0d08
File content as of revision 8:6a3b7c5d9ba7:
#include "STMClient.h" #include "millis.h" #define xstr(s) str(s) #define str(s) #s #define SLIP_END 0300 // indicates end of packet #define SLIP_ESC 0333 // indicates byte stuffing #define SLIP_ESC_END 0334 // ESC ESC_END means END data byte #define SLIP_ESC_ESC 0335 // ESC ESC_ESC means ESC data byte //===== Input // Process a received SLIP message STMClientPacket* STMClient::protoCompletedCb(void) { // the packet starts with a STMClientPacket STMClientPacket* packet = (STMClientPacket*)_proto.buf; if (_debugEn) { // _debug->printf("STMC: got %i @ %i:\n\r 0x%x\n\r 0x%x\n\r 0x%x\n\r", _proto.dataLen,(uint32_t)_proto.buf, packet->cmd, packet->value, packet->argc); for (uint16_t i=8; i<_proto.dataLen; i++) { // _debug->printf("%x", *(uint8_t*)(_proto.buf+i)); } //_debug->printf("\n\r"); } // verify CRC uint16_t crc = crc16Data(_proto.buf, _proto.dataLen-2, 0); //_debug->printf("CRC: %i\n\r",crc); //wait(0.5); uint16_t resp_crc = *(uint16_t*)(_proto.buf+_proto.dataLen-2); //_debug->printf("resp_crc: %i\n\r",resp_crc); if (crc != resp_crc) { DBG("STMC: Invalid CRC\n\r"); wait(0.25); return NULL; //maybe the CRC isn't getting calculated correctly... } // dispatch based on command if (packet->cmd == CMD_RESP_V) { // value response _debug->printf("RESP_V: 0x%x \n\r",packet->value); return packet; } else if (packet->cmd == CMD_RESP_CB) { FP<void, void*> *fp; // callback reponse _debug->printf("RESP_CB: 0x%x 0x%x \n\r", packet->value, packet->argc); fp = (FP<void, void*>*)packet->value; if (fp->attached()) { STMClientResponse resp(packet); (*fp)(&resp); } return NULL; } else { // command (NOT IMPLEMENTED) _debug->printf("CMD 0x%x Value 0x%x ??\n\r", packet->cmd, packet->value); return NULL; } } // Read all characters available on the serial input and process any messages that arrive, but // stop if a non-callback response comes in STMClientPacket *STMClient::Process() { int value; while (_serial->readable()) { value = _serial->getc(); if (value == SLIP_ESC) { _proto.isEsc = 1; } else if (value == SLIP_END) { STMClientPacket *packet = _proto.dataLen >= 8 ? protoCompletedCb() : 0; _proto.dataLen = 0; _proto.isEsc = 0; if (packet != NULL) return packet; } else { if (_proto.isEsc) { if (value == SLIP_ESC_END) value = SLIP_END; if (value == SLIP_ESC_ESC) value = SLIP_ESC; _proto.isEsc = 0; } if (_proto.dataLen < _proto.bufSize) { _proto.buf[_proto.dataLen++] = value; } } } return NULL; } //===== Output // Write a byte to the output stream and perform SLIP escaping void STMClient::write(uint8_t data) { switch (data) { case SLIP_END: _serial->putc(SLIP_ESC); _serial->putc(SLIP_ESC_END); break; case SLIP_ESC: _serial->putc(SLIP_ESC); _serial->putc(SLIP_ESC_ESC); break; default: _serial->putc(data); } } // Write some bytes to the output stream void STMClient::write(void* data, uint16_t len) { uint8_t *d = (uint8_t*)data; //_debug->printf("Writing: 0x%x\n\r", (const char*)data); while (len--) { write(*d++); } } // Start a request. cmd=command, value=address of callback pointer or first arg, // argc=additional argument count void STMClient::Request(uint16_t cmd, uint32_t value, uint16_t argc) { //_debug->printf("Starting a request...\n\r"); wait(0.25); crc = 0; _serial->putc(SLIP_END); write(&cmd, 2); crc = crc16Data((unsigned const char*)&cmd, 2, crc); write(&argc, 2); crc = crc16Data((unsigned const char*)&argc, 2, crc); write(&value, 4); crc = crc16Data((unsigned const char*)&value, 4, crc); } // Append a block of data as an argument to the request void STMClient::Request(const void* data, uint16_t len) { uint8_t *d = (uint8_t*)data; // write the length write(&len, 2); crc = crc16Data((unsigned const char*)&len, 2, crc); // output the data for (uint16_t l=len; l>0; l--) { write(*d); crc = crc16Add(*d, crc); d++; } // output padding uint16_t pad = (4-(len&3))&3; uint8_t temp = 0; while (pad--) { write(temp); crc = crc16Add(temp, crc); } } /* // Append a block of data located in flash as an argument to the request void STMClient::Request(const __FlashStringHelper* data, uint16_t len) { // write the length write(&len, 2); crc = crc16Data((unsigned const char*)&len, 2, crc); // output the data PGM_P p = reinterpret_cast<PGM_P>(data); for (uint16_t l=len; l>0; l--) { uint8_t c = pgm_read_byte(p++); write(c); crc = crc16Add(c, crc); } // output padding uint16_t pad = (4-(len&3))&3; uint8_t temp = 0; while (pad--) { write(temp); crc = crc16Add(temp, crc); } } */ // Append the final CRC to the request and finish the request void STMClient::Request(void) { write((uint8_t*)&crc, 2); _serial->putc(SLIP_END); } //===== Initialization void STMClient::init() { _proto.buf = _protoBuf; _proto.bufSize = sizeof(_protoBuf); _proto.dataLen = 0; _proto.isEsc = 0; } STMClient::STMClient(Serial* serial) : _serial(serial) { _debugEn = false; init(); } STMClient::STMClient(Serial* serial, Serial* debug) : _debug(debug), _serial(serial) { _debugEn = true; init(); } void STMClient::DBG(const char* info) { if (_debugEn) _debug->printf(info); } //===== Responses // Wait for a response for a given timeout STMClientPacket *STMClient::WaitReturn(uint32_t timeout) { uint32_t wait = millis(); while (millis() - wait < timeout) { STMClientPacket *packet = Process(); if (packet != NULL) return packet; } return NULL; } //===== CRC hSTMper functions uint16_t STMClient::crc16Add(unsigned char b, uint16_t acc) { acc ^= b; acc = (acc >> 8) | (acc << 8); acc ^= (acc & 0xff00) << 4; acc ^= (acc >> 8) >> 4; acc ^= (acc & 0xff00) >> 5; return acc; } uint16_t STMClient::crc16Data(const unsigned char *data, uint16_t len, uint16_t acc) { for (uint16_t i=0; i<len; i++) acc = crc16Add(*data++, acc); return acc; } //===== Basic requests built into STMClient bool STMClient::Sync(uint32_t timeout) { //_debug->printf("syncing..."); wait(0.5); // send sync request Request(CMD_SYNC, (uint32_t)&wifiCb, 0); Request(); // empty the response queue hoping to find the wifiCb address STMClientPacket *packet; while ((packet = WaitReturn(timeout)) != NULL) { if (packet->value == (uint32_t)&wifiCb) { // _debug->printf("SYNC!"); wait(0.5); return true; } _debug->printf("BAD: %s /n/r", packet->value); } // doesn't look like we got a real response return false; } //look in cmd.c for this. Puts ESP to sleep until a fall edge triggers on RST for it to reset. void STMClient::Sleep(void){ Request(CMD_SLEEP, 0, 0); Request(); } void STMClient::GetWifiStatus(void) { Request(CMD_WIFI_STATUS, 0, 0); Request(); }