Files
OpenMQTT-Gateway/main/ZgatewayRS232.ino
T
Merijn 6e3e8c3330 [RS232] add JSON parsing and hardware serial support to RS232 gateway (#1409)
* add JSON parse option to RS232 gateway

* add hardware UART support to RS232 gateway

* changed default RS232toMQTTmode to raw (instead of JSON)

* removed reference to Arduino Mega in RS232 gateway config

* update RS232 gateway doc
2023-01-25 16:43:53 -06:00

209 lines
7.2 KiB
Arduino

/*
OpenMQTTGateway - ESP8266 or Arduino program for home automation
Act as a wifi or ethernet gateway between your RS232 device and a MQTT broker
Send and receiving command by MQTT
This gateway enables to:
- receive MQTT data from a topic and send RS232 signal corresponding to the received MQTT data
- publish MQTT data to a different topic related to received RS232 signal
Copyright: (c)Florian ROBERT
This file is part of OpenMQTTGateway.
OpenMQTTGateway 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.
OpenMQTTGateway 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 <http://www.gnu.org/licenses/>.
*/
#include "User_config.h"
#ifdef ZgatewayRS232
# ifndef RS232_UART // software serial mode
# include <SoftwareSerial.h>
SoftwareSerial RS232SoftSerial(RS232_RX_GPIO, RS232_TX_GPIO); // RX, TX
# endif
// use pointer to stream class for serial communication to make code
// compatible with both softwareSerial as hardwareSerial.
Stream* RS232Stream = NULL;
void setupRS232() {
//Initalize serial port
# ifdef RS232_UART // Hardware serial
# if RS232_UART == 0 // init UART0
Serial.end(); // stop if already initialized
# ifdef ESP32
Serial.begin(RS232Baud, SERIAL_8N1, RS232_RX_GPIO, RS232_TX_GPIO);
# else
Serial.begin(RS232Baud, SERIAL_8N1);
# endif
# if defined(ESP8266) && defined(RS232_UART0_SWAP)
Serial.swap(); // swap UART0 ports from (GPIO1,GPIO3) to (GPIO15,GPIO13)
# endif
RS232Stream = &Serial;
Log.notice(F("RS232 HW UART0" CR));
# elif RS232_UART == 1 // init UART1
Serial1.end(); // stop if already initialized
# ifdef ESP32
Serial1.begin(RS232Baud, SERIAL_8N1, RS232_RX_GPIO, RS232_TX_GPIO);
# else
Serial1.begin(RS232Baud, SERIAL_8N1);
# endif
RS232Stream = &Serial1;
Log.notice(F("RS232 HW UART1" CR));
# elif RS232_UART == 2 // init UART2
Serial2.end(); // stop if already initialized
# ifdef ESP32
Serial2.begin(RS232Baud, SERIAL_8N1, RS232_RX_GPIO, RS232_TX_GPIO);
# else
Serial2.begin(RS232Baud, SERIAL_8N1);
# endif
RS232Stream = &Serial2;
Log.notice(F("RS232 HW UART2" CR));
# elif RS232_UART == 3 // init UART3
Serial3.end(); // stop if already initialized
Serial3.begin(RS232Baud, SERIAL_8N1);
RS232Stream = &Serial3;
Log.notice(F("RS232 HW UART3" CR));
# endif
# else // Software serial
// define pin modes for RX, TX:
pinMode(RS232_RX_GPIO, INPUT);
pinMode(RS232_TX_GPIO, OUTPUT);
RS232SoftSerial.begin(RS232Baud);
RS232Stream = &RS232SoftSerial; // get stream of serial
Log.notice(F("RS232_RX_GPIO: %d" CR), RS232_RX_GPIO);
Log.notice(F("RS232_TX_GPIO: %d" CR), RS232_TX_GPIO);
# endif
// Flush all bytes in the "link" serial port buffer
while (RS232Stream->available() > 0)
RS232Stream->read();
Log.notice(F("RS232Baud: %d" CR), RS232Baud);
Log.trace(F("ZgatewayRS232 setup done" CR));
}
# if RS232toMQTTmode == 0 // Convert received data to single MQTT topic
void RS232toMQTT() {
// Send all RS232 output (up to RS232InPost char revieved) as MQTT message
//This function is Blocking, but there should only ever be a few bytes, usually an ACK or a NACK.
if (RS232Stream->available()) {
Log.trace(F("RS232toMQTT" CR));
static char RS232data[MAX_INPUT];
static unsigned int input_pos = 0;
static char inChar;
do {
if (RS232Stream->available()) {
inChar = RS232Stream->read();
RS232data[input_pos] = inChar;
input_pos++;
Log.trace(F("Received %c" CR), inChar);
}
} while (inChar != RS232InPost && input_pos < MAX_INPUT);
RS232data[input_pos] = 0;
input_pos = 0;
Log.trace(F("Publish %s" CR), RS232data);
char* output = RS232data + sizeof(RS232Pre) - 1;
pub(subjectRS232toMQTT, output);
}
}
# elif RS232toMQTTmode == 1 // Convert recievee JSON data to multiple MQTT topics based (nested) keys
void RS232toMQTT() {
// Assumes valid JSON data at RS232 interface. Use (nested) keys to split JSON data in separate
// sub-MQTT-topics up to the defined nesting level.
if (RS232Stream->available()) {
Log.trace(F("RS232toMQTT" CR));
// Allocate the JSON document
StaticJsonDocument<RS232JSONDocSize> doc;
// Read the JSON document from the "link" serial port
DeserializationError err = deserializeJson(doc, *RS232Stream);
if (err == DeserializationError::Ok) {
// JSON received, send as MQTT topics
char topic[mqtt_topic_max_size + 1] = subjectRS232toMQTT;
sendMQTTfromNestedJson(doc.as<JsonVariant>(), topic, 0, RS232maxJSONlevel);
} else {
// Print error to serial log
Log.error(F("Error in RS232JSONtoMQTT, deserializeJson() returned %s"), err.c_str());
// Flush all bytes in the "link" serial port buffer
while (RS232Stream->available() > 0)
RS232Stream->read();
}
}
}
void sendMQTTfromNestedJson(JsonVariant obj, char* topic, int level, int maxLevel) {
// recursively step through JSON data and send MQTT messages
if (level < maxLevel && obj.is<JsonObject>()) {
int topicLength = strlen(topic);
// loop over fields
for (JsonPair pair : obj.as<JsonObject>()) {
// check if new key still fits in topic cstring
const char* key = pair.key().c_str();
Log.trace(F("level=%d, key='%s'" CR), level, pair.key().c_str());
if (topicLength + 2 + strlen(key) <= mqtt_topic_max_size) {
// add new level to existing topic cstring
topic[topicLength] = '/'; // add slash
topic[topicLength + 1] = '\0'; // terminate
strncat(topic + topicLength, key, mqtt_topic_max_size - topicLength - 2);
// step recursively into next level
sendMQTTfromNestedJson(pair.value(), topic, level + 1, maxLevel);
// restore topic
topic[topicLength] = '\0';
} else {
Log.error(F("Nested key '%s' at level %d does not fit within max topic length of %d, skipping"),
key, level, mqtt_topic_max_size);
}
}
} else {
// output value at current json level
char output[MAX_INPUT + 1];
serializeJson(obj, output, MAX_INPUT);
Log.notice(F("level=%d, topic=%s, value: %s\n"), level, topic, output);
// send MQTT message
pub(topic, &output[0]);
}
}
# endif
void MQTTtoRS232(char* topicOri, JsonObject& RS232data) {
Log.trace(F("json" CR));
if (cmpToMainTopic(topicOri, subjectMQTTtoRS232)) {
Log.trace(F("MQTTtoRS232 json" CR));
const char* data = RS232data["value"];
const char* prefix = RS232data["prefix"] | RS232Pre;
const char* postfix = RS232data["postfix"] | RS232Post;
Log.trace(F("Value set: %s" CR), data);
Log.trace(F("Prefix set: %s" CR), prefix);
Log.trace(F("Postfix set: %s" CR), postfix);
RS232Stream->print(prefix);
RS232Stream->print(data);
RS232Stream->print(postfix);
}
}
#endif