ESP8266 Community Forum

I have a couple of solar inverters connected to the grid. Each has a full duplex RS485 port so with the help of my son to put the magic software in, I can now monitor them.

The code on the ESPe266 is.....

/*
ESP8266 mDNS serial wifi bridge by Daniel Parnell 2nd of May 2015
*/

// #define BONJOUR_SUPPORT

#include <ESP8266WiFi.h>
#ifdef BONJOUR_SUPPORT
#include <ESP8266mDNS.h>
#endif
#include <WiFiClient.h>

#include "esp8266_pwm.h"

// application config

// comment out the following line to enable DHCP
#define STATIC_IP

#ifdef STATIC_IP
// change the IP address and gateway to match your network
#define IP_ADDRESS "192.168.1.88"
#define GATEWAY_ADDRESS "192.168.1.1"
#define NET_MASK "255.255.255.0"
#endif

#define WIFI_SSID "My_SSID"
#define WIFI_PASSWORD "My_WiFi_Password"
#define BAUD_RATE 9600
#define TCP_LISTEN_PORT 9999

// if the bonjour support is turned on, then use the following as the name
#define DEVICE_NAME "ser2net"

// serial end ethernet buffer size
#define BUFFER_SIZE 128

// hardware config
#define WIFI_LED 14
#define CONNECTION_LED 16
#define TX_LED 12
#define RX_LED 13

#ifdef BONJOUR_SUPPORT
// multicast DNS responder
MDNSResponder mdns;
#endif

WiFiServer server(TCP_LISTEN_PORT);

#ifdef STATIC_IP
IPAddress parse_ip_address(const char *str) {
IPAddress result;
int index = 0;

result[0] = 0;
while (*str) {
if (isdigit((unsigned char)*str)) {
result[index] *= 10;
result[index] += *str - '0';
} else {
index++;
if(index<4) {
result[index] = 0;
}
}
str++;
}

return result;
}

#endif

void connect_to_wifi() {
int count = 0;

#ifdef STATIC_IP
IPAddress ip_address = parse_ip_address(IP_ADDRESS);
IPAddress gateway_address = parse_ip_address(GATEWAY_ADDRESS);
IPAddress netmask = parse_ip_address(NET_MASK);

WiFi.config(ip_address, gateway_address, netmask);
#endif

digitalWrite(CONNECTION_LED, LOW);
digitalWrite(TX_LED, LOW);
digitalWrite(RX_LED, LOW);

// Wait for WIFI connection
while (WiFi.status() != WL_CONNECTED) {
pwm.set(0, (count & 1) ? 255 : 0);
// digitalWrite(WIFI_LED, (count & 1) ? HIGH : LOW);
count++;
delay(250);
}

pwm.set(0, 255);
// digitalWrite(WIFI_LED, HIGH);
}

void error() {
int count = 0;
digitalWrite(CONNECTION_LED, LOW);
digitalWrite(TX_LED, LOW);
digitalWrite(RX_LED, LOW);

while(1) {
count++;
digitalWrite(WIFI_LED, (count & 1) ? HIGH : LOW);
delay(100);
}
}

void setup(void)
{
digitalWrite(WIFI_LED, LOW);
digitalWrite(CONNECTION_LED, LOW);
digitalWrite(TX_LED, LOW);
digitalWrite(RX_LED, LOW);

pinMode(WIFI_LED, OUTPUT);
pinMode(CONNECTION_LED, OUTPUT);
pinMode(TX_LED, OUTPUT);
pinMode(RX_LED, OUTPUT);

// set up the Wifi LED for PWM
pwm.connect(0, WIFI_LED);
pwm.set(0, 0);
pwm.begin(1, 500);

Serial.begin(BAUD_RATE);

// Connect to WiFi network
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
connect_to_wifi();

#ifdef BONJOUR_SUPPORT
// Set up mDNS responder:
if (!mdns.begin(DEVICE_NAME, WiFi.localIP())) {
error();
}
#endif

// Start TCP server
server.begin();
}

WiFiClient client;
uint8 pulse = 0;
uint8 pulse_dir = 1;
int pulse_counter = 1;

void loop(void)
{
int bytes_read;
uint8_t net_buf[BUFFER_SIZE];
uint8_t serial_buf[BUFFER_SIZE];

if(WiFi.status() != WL_CONNECTED) {
// we've lost the connection, so we need to reconnect
if(client) {
client.stop();
}
connect_to_wifi();
}

pulse_counter--;
if(pulse_counter == 0) {
pulse_counter = 1000;
if(pulse_dir) {
pulse++;
if(pulse == 255) {
pulse_dir = 0;
}
} else {
pulse--;
if(pulse == 0) {
pulse_dir = 1;
}
}

pwm.set(0, pulse);
}

#ifdef BONJOUR_SUPPORT
// Check for any mDNS queries and send responses
mdns.update();
#endif

// Check if a client has connected
if (!client) {
client = server.available();
if(!client) {
// eat any bytes in the serial buffer as there is nothing to see them
while(Serial.available()) {
Serial.read();
}

digitalWrite(CONNECTION_LED, LOW);
return;
}
digitalWrite(CONNECTION_LED, HIGH);
}

if(client.connected()) {
// check the network for any bytes to send to the serial
int count = client.available();
if(count > 0) {
digitalWrite(TX_LED, HIGH);

bytes_read = client.read(net_buf, min(count, BUFFER_SIZE));
Serial.write(net_buf, bytes_read);
Serial.flush();
} else {
digitalWrite(TX_LED, LOW);
}

// now check the serial for any bytes to send to the network
bytes_read = 0;
while(Serial.available() && bytes_read < BUFFER_SIZE) {
serial_buf[bytes_read] = Serial.read();
bytes_read++;
}

if(bytes_read > 0) {
digitalWrite(RX_LED, HIGH);
client.write(serial_buf, bytes_read);
client.flush();
} else {
digitalWrite(RX_LED, LOW);
}

} else {
// make sure the TX and RX LEDs aren't on
digitalWrite(TX_LED, LOW);
digitalWrite(RX_LED, LOW);
digitalWrite(CONNECTION_LED, LOW);

client.stop();
}
}

I've added 2 x 3.3V RS485 drivers and a 3.3V regulator as the inverters supply about 8V when they are running.
The circuit is pretty rough at the moment but I hope to do a PCB when I get time.

The code has been updated as the old one created an access point as well.


/*
ESP8266 mDNS serial wifi bridge by Daniel Parnell 2nd of May 2015
*/

//#define BONJOUR_SUPPORT

#include <ESP8266WiFi.h>
#ifdef BONJOUR_SUPPORT
#include <ESP8266mDNS.h>
#endif
#include <WiFiClient.h>

#include "esp8266_pwm.h"

// application config

// comment out the following line to enable DHCP
#define STATIC_IP

#ifdef STATIC_IP
// change the IP address and gateway to match your network
#define IP_ADDRESS "192.168.10.42"
#define GATEWAY_ADDRESS "192.168.10.1"
#define NET_MASK "255.255.255.0"
#endif

// change the WiFi info to match your network
#define WIFI_SSID "myWiFiSSID"
#define WIFI_PASSWORD "myWiFiPassword"
#define BAUD_RATE 9600
#define TCP_LISTEN_PORT 9999

// if the bonjour support is turned on, then use the following as the name
#define DEVICE_NAME "ser2net"

// serial end ethernet buffer size
#define BUFFER_SIZE 128

// hardware config
#define WIFI_LED 14
//#define CONNECTION_LED 16
#define TX_LED 12
#define RX_LED 13

#ifdef BONJOUR_SUPPORT
// multicast DNS responder
MDNSResponder mdns;
#endif

WiFiServer server(TCP_LISTEN_PORT);
ESP8266_PWM pwm;

#ifdef STATIC_IP
IPAddress parse_ip_address(const char *str) {
IPAddress result;
int index = 0;

result[0] = 0;
while (*str) {
if (isdigit((unsigned char)*str)) {
result[index] *= 10;
result[index] += *str - '0';
} else {
index++;
if(index<4) {
result[index] = 0;
}
}
str++;
}

return result;
}

#endif

void connect_to_wifi() {
int count = 0;

WiFi.mode(WIFI_STA);
WiFi.disconnect();
delay(100);
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);

#ifdef STATIC_IP
IPAddress ip_address = parse_ip_address(IP_ADDRESS);
IPAddress gateway_address = parse_ip_address(GATEWAY_ADDRESS);
IPAddress netmask = parse_ip_address(NET_MASK);

WiFi.config(ip_address, gateway_address, netmask);
#endif

#ifdef CONNECTION_LED
digitalWrite(CONNECTION_LED, LOW);
#endif
digitalWrite(TX_LED, LOW);
digitalWrite(RX_LED, LOW);

// Wait for WIFI connection
while (WiFi.status() != WL_CONNECTED) {
pwm.set(0, (count & 1) ? PWM_MAX_DUTY : 0);
count++;
delay(250);
}

pwm.set(0, PWM_MAX_DUTY);
}

void error() {
int count = 0;

#ifdef CONNECTION_LED
digitalWrite(CONNECTION_LED, LOW);
#endif
digitalWrite(TX_LED, LOW);
digitalWrite(RX_LED, LOW);

while(1) {
count++;
pwm.set(0, (count & 1) ? PWM_MAX_DUTY : 0);
delay(100);
}
}

void setup(void)
{
digitalWrite(WIFI_LED, LOW);
#ifdef CONNECTION_LED
digitalWrite(CONNECTION_LED, LOW);
#endif
digitalWrite(TX_LED, LOW);
digitalWrite(RX_LED, LOW);

pinMode(WIFI_LED, OUTPUT);
#ifdef CONNECTION_LED
pinMode(CONNECTION_LED, OUTPUT);
#endif
pinMode(TX_LED, OUTPUT);
pinMode(RX_LED, OUTPUT);

// set up the Wifi LED for PWM
pwm.connect(0, WIFI_LED);
pwm.set(0, 0);
pwm.begin(1, 500);

Serial.begin(BAUD_RATE);

// Connect to WiFi network
connect_to_wifi();

#ifdef BONJOUR_SUPPORT
// Set up mDNS responder:
if (!mdns.begin(DEVICE_NAME, WiFi.localIP())) {
error();
}
#endif

// Start TCP server
server.begin();
}

WiFiClient client;
uint8 pulse = 0;
uint8 pulse_dir = 1;
int pulse_counter = 1;

void loop(void)
{
int bytes_read;
uint8_t net_buf[BUFFER_SIZE];
uint8_t serial_buf[BUFFER_SIZE];

if(WiFi.status() != WL_CONNECTED) {
// we've lost the connection, so we need to reconnect
if(client) {
client.stop();
}
connect_to_wifi();
}

pulse_counter--;
if(pulse_counter == 0) {
pulse_counter = 1000;
if(pulse_dir) {
pulse++;
if(pulse == PWM_MAX_DUTY) {
pulse_dir = 0;
}
} else {
pulse--;
if(pulse == 0) {
pulse_dir = 1;
}
}

pwm.set(0, pulse);
}

#ifdef BONJOUR_SUPPORT
// Check for any mDNS queries and send responses
mdns.update();
#endif

// Check if a client has connected
if (!client) {
// eat any bytes in the serial buffer as there is nothing to see them
while(Serial.available()) {
Serial.read();
}

client = server.available();
if(!client) {
#ifdef CONNECTION_LED
digitalWrite(CONNECTION_LED, LOW);
#endif
return;
}

#ifdef CONNECTION_LED
digitalWrite(CONNECTION_LED, HIGH);
#endif
}

if(client.connected()) {
// check the network for any bytes to send to the serial
int count = client.available();
if(count > 0) {
digitalWrite(TX_LED, HIGH);

bytes_read = client.read(net_buf, min(count, BUFFER_SIZE));
Serial.write(net_buf, bytes_read);
Serial.flush();
} else {
digitalWrite(TX_LED, LOW);
}

// now check the serial for any bytes to send to the network
bytes_read = 0;
while(Serial.available() && bytes_read < BUFFER_SIZE) {
serial_buf[bytes_read] = Serial.read();
bytes_read++;
}

if(bytes_read > 0) {
digitalWrite(RX_LED, HIGH);
client.write(serial_buf, bytes_read);
client.flush();
} else {
digitalWrite(RX_LED, LOW);
}

} else {
// make sure the TX and RX LEDs aren't on
digitalWrite(TX_LED, LOW);
digitalWrite(RX_LED, LOW);
#ifdef CONNECTION_LED
digitalWrite(CONNECTION_LED, LOW);
#endif

client.stop();
}
}

Hi Dendad51,
I'm interested in your project. I have 2 solar inverter connected to a PC by RS485, cabled, and now I wold be able to move the communication throught WiFi.
Please, can you share also the electric diagram of your project?
Andrea.