/*
xsns_22_sr04.ino - SR04 ultrasonic sensor support for Tasmota
Copyright (C) 2021 Nuno Ferreira and Theo Arends
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see .
*/
#ifdef USE_SR04
/*********************************************************************************************\
* HC-SR04, HC-SR04+, JSN-SR04T - Ultrasonic distance sensor
*
* Code for SR04 family of ultrasonic distance sensors
* References:
* - https://www.dfrobot.com/wiki/index.php/Weather-proof_Ultrasonic_Sensor_SKU_:_SEN0207
\*********************************************************************************************/
#define XSNS_22 22
#ifndef SR04_MAX_SENSOR_DISTANCE
#define SR04_MAX_SENSOR_DISTANCE 500
#endif
enum Sr04CommsMode { SR04_MODE_NONE, // No hardware detected
SR04_MODE_TRIGGER_ECHO, // Mode 1 - Trigger and Echo connection
SR04_MODE_SER_RECEIVER, // Mode 2 - Serial receive only
SR04_MODE_SER_TRANSCEIVER, // Mode 3 - Serial transmit and receive
SR04_NOT_DETECTED }; // Not yet detected
#include
#include
struct {
float distance;
uint8_t valid;
uint8_t type = SR04_NOT_DETECTED;
} SR04;
NewPing* sonar = nullptr;
TasmotaSerial* sonar_serial = nullptr;
uint16_t Sr04TMiddleValue(uint16_t first, uint16_t second, uint16_t third) {
uint16_t ret = first;
if (first > second) {
first = second;
second = ret;
}
if (third < first) {
return first;
} else if (third > second) {
return second;
} else {
return third;
}
}
uint16_t Sr04TMode2Distance(void) {
uint8_t buffer[4]; // Accommodate either 2 or 4 bytes of data
uint32_t buffer_idx = 0;
uint32_t end = millis() + 100;
while (millis() < end) {
if (sonar_serial->available() && (buffer_idx < sizeof(buffer))) {
buffer[buffer_idx++] = sonar_serial->read();
end = millis() + 10;
}
delay(1);
}
if (SR04_MODE_NONE == SR04.type) { // Only log during detection
AddLog(LOG_LEVEL_DEBUG, PSTR("SR4: Received '%*_H'"), buffer_idx, buffer);
}
uint32_t distance = 0;
if (buffer_idx > 2) { // JSN-SR04T serial has four bytes
// FF00FAF9
uint8_t crc = buffer[0];
crc += buffer[1];
crc += buffer[2];
if (crc == buffer[3]) { // Check crc sum
distance = (buffer[1] << 8) + buffer[2];
} else {
AddLog(LOG_LEVEL_ERROR, PSTR("SR4: CRC error"));
}
}
else if (buffer_idx > 1) { // US-100 serial has no CRC
// 00FA = 250 millimeter
distance = (buffer[0] << 8) + buffer[1];
}
return distance;
}
uint16_t Sr04TMode3Distance() {
sonar_serial->write(0x55);
sonar_serial->flush();
return Sr04TMode2Distance();
}
/*********************************************************************************************/
void Sr04TModeDetect(void) {
SR04.type = SR04_MODE_NONE;
if (!PinUsed(GPIO_SR04_ECHO)) { return; }
int sr04_echo_pin = Pin(GPIO_SR04_ECHO);
int sr04_trig_pin = Pin(GPIO_SR04_TRIG); // if GPIO_SR04_TRIG is not configured use single PIN mode with GPIO_SR04_TRIG as -1
sonar_serial = new TasmotaSerial(sr04_echo_pin, sr04_trig_pin, 1);
if (sonar_serial && sonar_serial->begin(9600)) {
DEBUG_SENSOR_LOG(PSTR("SR4: Detect mode"));
if (PinUsed(GPIO_SR04_TRIG)) {
SR04.type = (Sr04TMiddleValue(Sr04TMode3Distance(), Sr04TMode3Distance(), Sr04TMode3Distance()) != 0) ? SR04_MODE_SER_TRANSCEIVER : SR04_MODE_TRIGGER_ECHO;
} else {
SR04.type = (Sr04TMiddleValue(Sr04TMode2Distance(), Sr04TMode2Distance(), Sr04TMode2Distance()) != 0) ? SR04_MODE_SER_RECEIVER : SR04_MODE_TRIGGER_ECHO;
}
} else {
SR04.type = SR04_MODE_TRIGGER_ECHO;
}
if (SR04.type < SR04_MODE_SER_RECEIVER) {
if (sonar_serial) {
delete sonar_serial;
sonar_serial = nullptr;
}
sr04_trig_pin = (PinUsed(GPIO_SR04_TRIG)) ? Pin(GPIO_SR04_TRIG) : Pin(GPIO_SR04_ECHO); // if GPIO_SR04_TRIG is not configured use single PIN mode with GPIO_SR04_ECHO only
sonar = new NewPing(sr04_trig_pin, sr04_echo_pin, SR04_MAX_SENSOR_DISTANCE);
delay(100); // give time to inizialise, preventing ping_median fails
if (!sonar || !sonar->ping_median(5)) {
SR04.type = SR04_MODE_NONE;
}
} else {
if (sonar_serial) {
if (sonar_serial->hardwareSerial()) {
ClaimSerial();
}
#ifdef ESP32
AddLog(LOG_LEVEL_DEBUG, PSTR("SR4: Serial UART%d"), sonar_serial->getUart());
#endif
}
}
AddLog(LOG_LEVEL_INFO,PSTR("SR4: Mode %d"), SR04.type);
}
void Sr04TReading(void) {
if (TasmotaGlobal.uptime < 3) { return; }
if (SR04.valid) {
SR04.valid--;
} else {
SR04.distance = 0;
}
float distance;
switch (SR04.type) {
case SR04_NOT_DETECTED:
Sr04TModeDetect();
SR04.valid = (SR04.type) ? SENSOR_MAX_MISS : 0;
break;
case SR04_MODE_SER_TRANSCEIVER:
distance = (float)(Sr04TMiddleValue(Sr04TMode3Distance(), Sr04TMode3Distance(), Sr04TMode3Distance())) / 10; // Convert to cm
break;
case SR04_MODE_SER_RECEIVER:
//empty input buffer first
while(sonar_serial->available()) { sonar_serial->read(); }
distance = (float)(Sr04TMiddleValue(Sr04TMode2Distance(), Sr04TMode2Distance(), Sr04TMode2Distance())) / 10; // Convert to cm
break;
case SR04_MODE_TRIGGER_ECHO:
distance = (float)(sonar->ping_median(5)) / US_ROUNDTRIP_CM;
break;
default:
distance = 0;
}
if (distance) {
SR04.distance = distance;
SR04.valid = SENSOR_MAX_MISS;
}
}
void Sr04Show(bool json) {
if (SR04.valid) { // Check if read failed
if(json) {
ResponseAppend_P(PSTR(",\"SR04\":{\"" D_JSON_DISTANCE "\":%1_f}"), &SR04.distance);
#ifdef USE_DOMOTICZ
if (0 == TasmotaGlobal.tele_period) {
DomoticzFloatSensor(DZ_COUNT, SR04.distance); // Send distance as Domoticz Counter value
}
#endif // USE_DOMOTICZ
#ifdef USE_WEBSERVER
} else {
WSContentSend_PD(HTTP_SNS_F_DISTANCE_CM, "SR04", &SR04.distance);
#endif // USE_WEBSERVER
}
}
}
/*********************************************************************************************\
* Interface
\*********************************************************************************************/
bool Xsns22(uint32_t function) {
bool result = false;
if (SR04.type) {
switch (function) {
case FUNC_EVERY_SECOND:
Sr04TReading();
result = true;
break;
case FUNC_JSON_APPEND:
Sr04Show(1);
break;
#ifdef USE_WEBSERVER
case FUNC_WEB_SENSOR:
Sr04Show(0);
break;
#endif // USE_WEBSERVER
}
}
return result;
}
#endif // USE_SR04