I want to connect Nodemcu esp8266 and I2C 1602. I just want to show some text from esp8266 at I2C without any other sensor/hardware in between. What should be the pins' connection between the Nodemcu and I2C?
I would be very thankful if somebody please tell me the comparison of Nodemcu and Arduino pins?
Actually, there are a couple of examples to do this, but there is a library for I2C connection of common 16x2 LCD converters like this:
Just grab the library and put it in your libraries directory and use one of the examples:
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 20, 4); // set the LCD address to 0x27 for a 16 chars and 2 line display
void setup()
{
lcd.init(); // initialize the lcd
// Print a message to the LCD.
lcd.backlight();
lcd.setCursor(3, 0);
lcd.print("Hello, world!");
lcd.setCursor(2, 1);
lcd.print("Ywrobot Arduino!");
lcd.setCursor(0, 2);
lcd.print("Arduino LCM IIC 2004");
lcd.setCursor(2, 3);
lcd.print("Power By Ec-yuan!");
}
void loop()
{
}
Related
I'm trying to connect a soil sensor using RS485 communication to arduino mega and I can't get it to work. I'm using the SparkFun RS485 breakout: https://www.sparkfun.com/products/10124
I've connected TX to pin 18, RS to pin 19 and RTS to pin 8.
I've tried to adapt the code from here: https://www.youtube.com/watch?v=tBw15SfmuwI using the sensor's manufacturers default setting:
Modbus address fixed to 0
The communication configuration is 9600,N,8,1（9600bps， no check bit, 8 data bits,
1 stop bit）
Communication protocol is Modbus-RTU
While the addresses I need to read are 0x0000-0x0002.
However, I get random characters as output when I open the serial monitor "?", any idea why? I'd appreciate any help reading the sensor's output.
This is the code I've used:
#include <ModbusMaster.h>
#define MAX485_DE 8
#define MAX485_RE_NEG 8
ModbusMaster node;
void preTransmission () {
digitalWrite(MAX485_RE_NEG, 1);
digitalWrite(MAX485_DE, 1);
}
void postTransmission () {
digitalWrite(MAX485_RE_NEG, 0);
digitalWrite(MAX485_DE, 0);
}
void setup() {
pinMode(MAX485_RE_NEG, OUTPUT);
pinMode(MAX485_DE, OUTPUT);
digitalWrite(MAX485_RE_NEG, 0);
digitalWrite(MAX485_DE, 0);
Serial.begin(9600);
node.begin(0,Serial);
node.preTransmission(preTransmission);
node.postTransmission(postTransmission);
}
void loop() {
uint8_t resultMain;
resultMain = node.readInputRegisters(0x0000, 3);
if (resultMain == node.ku8MBSuccess) {
Serial.println("-------");
Serial.print("Temp: ");
Serial.println(node.getResponseBuffer(0x00) /100);
Serial.print("VWC: ");
Serial.println(node.getResponseBuffer(0x01) /100);
Serial.print("EC: ");
Serial.println(node.getResponseBuffer(0x02) /100);
}
}
The arduino mega has 3 serial ports:
Serial
Serial1
Serial2
You could think of it as Serial as Serial0 (the zero is never written). This port is hardwired to the USB port on the arduino mega.
Your RS485 breakout board is connected to Serial1. You may notice the screenprinting on the mega next to pins 18 and 19 says TX1 and RX1.
So when you initialize your node at this line:
node.begin(0,Serial);
you should pass it Serial1 instead of Serial
eg
node.begin(0,Serial1);
I want to check if communication is working between my SerialMonitor in Arduino IDE and BLE controller.
I typed command AT to my SerialMonitor and it suppose to return OK response but nothing happened.
This is scheme what I used:
Code:
#include <SoftwareSerial.h>
SoftwareSerial bleSerial(2, 3); // RX, TX
void setup() {
//initialize serial port for logs
Serial.begin(9600);
while (!Serial) {
}
bleSerial.begin(9600);
}
void loop() {
if (bleSerial.available()) {
Serial.write(bleSerial.read());
}
if (Serial.available()) {
bleSerial.write(Serial.read());
}
}
UPDATE:
Changed values for SoftwareSerial bleSerial(3, 2); // RX, TX still doesnt work.
UPDATE2:
I've tried switching pins and code, nothing works. I should at least see HM-10 controller in my bluetooth devices on my Android phone, but I cant see anything.
UPDATE3:
I've used code from this Stackoverflow post and its working fine. I can finally see controller in my bluetooth devices on my Android phone also It returned name MLT-BT05 after AT+NAME? command. Looks like you have to read message per char and put delay 10ms between chars, otherwise it will not be possible to read message from BLE controller. That was the only problem.
You should connect RX-TX and TX-RX (not RX-RX and TX-TX like your graphic shows) so change the cables and the code from
SoftwareSerial bleSerial(2, 3); // RX, TX
to
SoftwareSerial bleSerial(3, 2); // RX, TX
Connect according to this graphic (incl voltage divider)
Abd use the following sketch to test (read comments for details):
// SerialIn_SerialOut_HM-10_01
//
// Uses hardware serial to talk to the host computer and AltSoftSerial for communication with the bluetooth module
//
// What ever is entered in the serial monitor is sent to the connected device
// Anything received from the connected device is copied to the serial monitor
// Does not send line endings to the HM-10
//
// Pins
// BT VCC to Arduino 5V out.
// BT GND to GND
// Arduino D8 (SS RX) - BT TX no need voltage divider
// Arduino D9 (SS TX) - BT RX through a voltage divider (5v to 3.3v)
//
#include <SoftwareSerial.h>
SoftwareSerial BTserial;
char c=' ';
bool NL = true;
void setup()
{
Serial.begin(9600);
Serial.print("Sketch: "); Serial.println(__FILE__);
Serial.print("Uploaded: "); Serial.println(__DATE__);
Serial.println(" ");
BTserial.begin(9600);
Serial.println("BTserial started at 9600");
}
void loop()
{
// Read from the Bluetooth module and send to the Arduino Serial Monitor
if (BTserial.available())
{
c = BTserial.read();
Serial.write(c);
}
// Read from the Serial Monitor and send to the Bluetooth module
if (Serial.available())
{
c = Serial.read();
if (c!=10 & c!=13 )
{
BTserial.write(c);
}
// Echo the user input to the main window. The ">" character indicates the user entered text.
if (NL) { Serial.print("\r\n>"); NL = false; }
Serial.write(c);
if (c==10) { NL = true; }
}
}
I'm writing code to run on an ATtiny being programmed by an Arduino as ISP. The ATtiny is to send AT commands over serial link to an RN42 Bluetooth module.
Since the ATtiny has no UART I'm using SoftwareSerial on pins 0 and 1. It seemed logical to put Tx on the "Data Out"/MISO pin and Rx on the "Data In"/MOSI pin. The documentation says to declare this like SoftwareSerial mySerial(Rx, Tx); but I found it only works if you declare it the other way round like SoftwareSerial mySerial(Tx, Rx);
I've taken a screenshot of my code and the pinout, I feel like I'm missing something but when I do it like this it works and makes the Bluetooth module enter command mode. Is the documentation the wrong way round?
Code and Pinout
I realised the error of my ways, I was unnecessarily setting the pinMode of the Rx and Tx pins. This threw me off as I thought setting the Rx pin to OUTPUT wouldn't work when actually it does, so I was outputting data on my Rx line and receiving it on the Tx line! The answer is to not assign direction and just let SoftwareSerial handle the pins. Pass the parameters in the order (Rx, Tx).
Here is my cleaner code that is working much better:
#include <SoftwareSerial.h>
const int Rx = 0; // pin 5 on ATtiny - DI/MOSI
const int Tx = 1; // pin 6 on ATtiny - DO/MISO
const int ButtonIn = 2;
const int OK_LED = 4;
int buttonState = 0;
SoftwareSerial serialBT(Rx, Tx);
void setup()
{
pinMode(ButtonIn, INPUT);
pinMode(OK_LED, OUTPUT);
serialBT.begin(9600);
}
void loop()
{
buttonState = digitalRead(ButtonIn);
if (buttonState == 0)
{
serialBT.print("$"); // $$$ enters RN42 command mode
serialBT.print("$");
serialBT.print("$");
delay(3000);
serialBT.println("R,1");
digitalWrite(OK_LED, HIGH);
delay(5000);
digitalWrite(OK_LED, LOW);
}
}
I am trying to run 2 rfid readers (RDM 630) in an Arduino Mega 2560. I just can't figure it out why only one reader will read and the other won't. (The readers are both functional).
#include <SoftwareSerial.h>
SoftwareSerial Reader1(50, 51);
SoftwareSerial Reader2(52, 53);// RX and TX
int rfid, i;
char newtag[14];
void setup()
{
Reader1.begin(9600); // start serial to RFID reader
Reader2.begin(9600);
Serial.begin(9600); // start serial to PC
}
void loop()
{
if (Reader1.available() > 0)
{
Serial.println();
Serial.println();
Serial.println("Reading RFID Tag...");
delay(100);
for (i=0; i < 13; i++)
{
rfid = Reader1.read();
newtag[i]=rfid;
}
Reader1.flush();
Serial.print("RFID Tag No:");
Serial.print(newtag);
}
if (Reader2.available() > 0)
{
Serial.println();
Serial.println();
Serial.println("Reading RFID Tag...");
delay(100);
for (i=0; i < 13; i++)
{
rfid = Reader2.read();
newtag[i]=rfid;
}
Reader2.flush();
Serial.print("RFID Tag No:");
Serial.print(newtag);
}
}
SofwareSerial has shared resources so needs a little extra thought on implementation. When you initialise a device it is the listening device. If you initialise another the listening device changes. You need to put:
Reader1.listen();
Before your Reader1 code and switch again for your Reader2 code.
See this for example code: http://arduino.cc/en/Tutorial/TwoPortReceive
However, you say you have a Mega. Why not use the multiple serials you have onboard? Your code base will be smaller and the coding is cleaner. http://arduino.cc/en/Tutorial/MultiSerialMega
After around million of trying and trying I discovered that the correct way to connect 4 RFID RC522 is to put them in the same line on test board except SS pins and the code as usual is ReadUidMultiReader from RFID library like this :
I am trying to finish a small project with a moisture sensor connected to a Fio V3.
I have also attach a Xbee S1 module to Fio's socket.
I have upload the following code to Fio:
int igrasia = 7;
void setup()
{
Serial1.begin(9600);
pinMode(igrasia, INPUT_PULLUP);
}
void loop(){
int sensorVal = digitalRead(igrasia);
if (sensorVal == HIGH) {
Serial1.println("0"); // Send OK to xbee
}
else {
Serial1.println("1"); // Send NOT OK to xbee
}
delay(5000);
}
On my computer using the Xbee USB explorer I am receiving correct data on X-CTU every 5 seconds.
Zero (0) while the sensor is outside a glass of water and one (1) while the sensor is in the glass of water.
I want to read these bytes to an Arduino Uno with a LCD screen attached and an Xbee shield. For this reason I have uploaded to Uno the following code:
#include <SPI.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x38,16,2); // set the LCD address to 0x20 for a 16 chars
void setup(){
Serial.begin(9600);
//configure pin2 as an input and enable the internal pull-up resistor
// pinMode(8, INPUT_PULLUP);
pinMode(13, OUTPUT);
digitalWrite(13, LOW);
lcd.init(); // initialize the lcd
}
void loop(){
if(Serial.available())
{
char getData = Serial.read();
if (getData == '1')
{
Serial.print(getData);
digitalWrite(13, HIGH);
lcd.clear();
lcd.setCursor (0,0); // go to start of 1st line
lcd.print("ATTENTION !!!!");
lcd.setCursor (0,1); // go to start of 1st line
lcd.print("WET environment");
}
else {
Serial.print(getData);
digitalWrite(13, LOW);
lcd.clear();
lcd.setCursor (0,0); // go to start of 1st line
lcd.print("dry environment");
lcd.setCursor (0,1); // go to start of 1st line
lcd.print("all looks good!");
}
}
}
It doesn't work properly :- (
I have correct functionality for 0 and while the sensor is outside the water. LCD monitor shows "dry environment".
But as soon as I place the sensor in the water, LCD is not working as required.
Even if I leave the sensor in the water the LCD still displays "dry environment".
I tried the sensor connected directly to Uno with the LCD attached and it works!
I suppose something is wrong with the serial.read() and/or my If / loop statement on UNO.
Any suggestions or advice?
When you transmit the data, you're sending it as a String "1", "0".
On the receiver, you're testing for characters '1', '0'. Strings are terminated with a null character (/u0000), whereas characters are not. Therefore the condition is always failed. You could try transmitting and testing characters only.