I have a ladyada xbee adapter on the computer side and an arduino xbeeshield which I am trying to communicate with over wireless. Both xbees are configured correctly in that I can receive data from the xbeeshield to the computer. However it doesn't work the other way i.e. xbeeshield does not echo a byte sent from the computer serially. Any idea what I might be doing wrong? (Note: When I connect the arduino board to the computer using USB cable, the echo program works just fine. It seems to be a problem in wireless mode only)
processing code
void setup() {
Serial.begin(9600);
}
void loop() {
if (Serial.available()) {
Serial.print((char) Serial.read());
delay(10);
}
}
I am just sending keystrokes from computer and waiting for a reply. I am not getting any.
I use the code I answered to the following question in regards to sending serial bytes from PC to Xbee/Arduino. It's been working fine for months. Ensure you've configured both your Xbee modules on the PC and Arduino side. Ensure your PAN ID's are the same as well.
Arduino making decision according to a packet received from serial port
What version of the Xbee modules are you using? My code works with Series 1 but should work with newer versions as well.
Try using softwareSerial library and connecting Tx and Rx to pin 4 and 2. Run the following sketch and tell me what happens. Change the Baudrate value to match your own
#include <SoftwareSerial.h>
uint8_t pinRx = 2 , pinTx = 4; // the pin on Arduino
long BaudRate = 57600; // Please set your Baudrate. It should match the one in XC-TU
char GotChar, getData;
// Xbee SoftwareSerial initialization
SoftwareSerial xbee(pinRx, pinTx); // RX, TX
void setup()
{
Serial.begin(9600);
Serial.println( "Welcome to the XBee Communication Test" );
Serial.print("BaudRate:");
Serial.println(BaudRate);
Serial.print(" Rx Pin#");
Serial.println(pinRx,DEC);
Serial.print(" Tx Pin#");
Serial.println(pinTx,DEC);
// set the data rate for the SoftwareSerial port
xbee.begin( BaudRate );
xbee.println("Setup Completed!");
}
void loop()
{
if (Serial.available())
{
GotChar = Serial.read();
xbee.print(GotChar);
Serial.print(GotChar);
}
while (xbee.available()>0)
{
Serial.println("Ohohoh");
getData = xbee.read();
Serial.print(" Received: );
Serial.print(getData);
Serial.println();
if(getData == 'a')
{
Serial.println(" sbam");
}
else if(getData == 'b')
{
Serial.println(" sbo");
}
}
}
Upload the program and open the serial monitor. Do you get the 'Setup completed' message on the computer? What happens if you send 'a' or 'b' from the Pc to the Arduino?
Related
I'm trying to send data from Arduino UNO to NodeMCU via UART.
What I want to do is that when Arduino UNO sends "on" String to the NodeMCU, NodeMCU lights up its builtin LED, when "off" - it turns off.
I send data from Arduino UNO via standard Serial.println (). On the NodeMCU I use the SoftwareSerial library. I assigned rx and tx to pins D7 and D8 accordingly. Serial ports on Arduino(standard) and NodeMCU(SoftwareSerial) are set at 9600 baud rate.
Standard Serial port (USB) of NodeMCU is set to 115200.
I send the string that I receive from the Arduino to the standard serial port of the node (connected to usb)
The question is:
On the standard port of NodeMCU, which I view through the Arduino IDE, messages coming from the arduino are displayed, and displayed correctly (those that were sent), but the NodeMCU does not want to accept them in conditional statements and light up my LED. Why?
At the same time, when I remap the virtual UART to its original pins (connected to USB, GPIO3 and GPIO1, and send the same messages via usb through the COM port view in the Arduino IDE, the LED turns on and off as I programmed it.
Do you have any ideas why this is happening?
By the way, I do not lower voltage coming from Arduino RX and TX pins from 5V to 3.3V, but since messages are recived coorectly, I don't think that this is causing a problem.
Here's my code:
Arduino:
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
}
void loop() {
// put your main code here, to run repeatedly:
Serial.println("on");
delay(1000);
Serial.println("off");
delay(1000);
}
NodeMCU:
#include <SoftwareSerial.h>
SoftwareSerial s(D7,D8);//rx,tx
void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
s.begin(9600);
pinMode(D4,OUTPUT);
}
void loop() {
// put your main code here, to run repeatedly:
String str = s.readStringUntil('\n');
Serial.println(str);
if(str == "on"){
digitalWrite(D4, HIGH);
}
if(str=="off"){
digitalWrite(D4, LOW);
}
}
Screenshot of COM4:
Screenshot of COM4:
UPD: I tried using sending 1 or 0 as int value via Serial.write() and s.read() and it works, maybe the prolem is in String type somehow
You Use İt Maybe Work
#include <SoftwareSerial.h>
String text = "";
SoftwareSerial s(D7,D8);//rx,tx
void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
s.begin(9600);
pinMode(D4,OUTPUT);
}
void loop() {
// put your main code here, to run repeatedly:
String str = s.readStringUntil('\n');
text = str
Serial.println(text);
if(text == "on"){
digitalWrite(D4, HIGH);
}
if(text =="off"){
digitalWrite(D4, LOW);
}
}
I've been working on a project and want an Arduino uno with an HM-19 Bluetooth module to repeatedly send an AT command to the module then print the modules result in the serial monitor. I'm having trouble and it is only returning the number 53 and not the response 'OK'. Thanks for any insight you're able to give.
//import Software Serial to communicate over comms port
#include <SoftwareSerial.h>
// 0 and 1 are the tx and rx pins ans should be where the hm-19 is
// may be 0,1 instead
SoftwareSerial HM19(1,0);
void setup() {
// begin serial monitor and wait for something(?, found online)
Serial.begin(9600);
while (!Serial) {
; // wait for serial port to connect. Needed for native USB port only
}
//tell user it's started
Serial.println("Started");
//I believe this begins the monitor for the HM-19
HM19.begin(9600);
delay(1000);
}
void loop() {
// give user status report
delay(1000);
Serial.println("Sending an AT command...");
// need to find if this is how you send an AT command (currenty send 'AT' as a test)
HM19.write("AT\r");
delay(30);
//wait for the HM19 to respond then print it out
int HMresponse = 0;
if (HM19.available()){}
HMresponse = HM19.read();
Serial.println(HMresponse);
}
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 have the ESP8266 connected to my Arduino Uno. With a blank sketch I can use Serial Monitor to connect it to my wifi network using these commands
AT+IPR=9600
AT+CWMODE=1
AT+CWJAP="SSID_HERE",""
It get's an ip and everything. But now I want my sketch to just do this using this code
#include <SoftwareSerial.h>
#define SSID "SSID_HERE"
void setup(){
Serial.begin(9600);
Serial.setTimeout(5000);
delay(1000);
}
boolean connectWiFi()
{
// connect
Serial.println("AT+CWMODE=1");
Serial.println("AT+CWJAP=\"SSID_HERE\",\"\"");
delay(2000);
if(Serial.find("OK"))
{
Serial.println("AT+CIFSR");
Serial.flush();
delay(1000);
return true;
}
else
{
// Can not connect to the WiFi.
return false;
}
}
But it doesn't work.. The Serial.println shows up in the Serial Monitor, but the ESP8266 doesn't seem to respond. What am I missing?
AT -commands ends with carriage return, so you need to add '\r' to every command you print.
In your code lines looks like:
Serial.println("AT+CWMODE=1\r");
Serial.println("AT+CWJAP=\"SSID_HERE\",\"\"\r");
Serial.println("AT+CIFSR\r");
Reference: https://en.wikibooks.org/wiki/Serial_Programming/Modems_and_AT_Commands/Special_Commands_and_Character_Sequences
The problem here is that you are trying to use pins 0 & 1 for the serial comms, well its part of the problem.. Because the arduino uses serial as well, it for me is only really good to use pins 0 & 1 for serial when i've grounded the reset pin on the arduino. This turns the arduino into a dummy device.
You can use something like software serial and two different pins instead, this way you will not interfere with the hardware serial of the arduino.
Also just to note, the below example will barely work.. For some it will for others it wont.. The problem here is that software serial does not really work / run at 115200..
You can change baud rate via AT+UART_DEF=19200,8,1,0,0 which will also disable flow control, then use software serial with a different speed mySerial.begin(19200)
Using Serial.println("TEXT") will send the line returns for you, so no need to add them unless you use Serial.print("TEXT\r\n")
DO NOT USE: AT+IPR= as this will brick it and require a reflash
#include <SoftwareSerial.h>
SoftwareSerial mySerial(11, 10); // RX, TX
void setup() {
// Open serial communications and wait for port to open:
Serial.begin(115200);
pinMode(11, INPUT);
pinMode(10, OUTPUT);
while (!Serial) {
; // wait for serial port to connect. Needed for native USB port only
}
Serial.println("ARDUINO: Starting");
mySerial.begin(115200);
Serial.println("ARDUINO: Sending AT Command");
mySerial.println("AT");
}
void loop() { // run over and over
if (mySerial.available()) {
Serial.write(mySerial.read());
}
if (Serial.available()) {
mySerial.write(Serial.read());
}
}
I'm trying to make modbus RS-485 connection between PC (Windows) and Arduino.
On the PC side I use USB-to-RS485 converter like this one http://ru.aliexpress.com/item/USB-to-485-RS485-converter-Adapter-Support-Windows-7-8-for-Arduino/1577970568.html
On the Arduino side I use TTL-to-RS-485 like this one http://ru.aliexpress.com/item/5pcs-lot-MAX485-Module-RS-485-TTL-to-RS485-Module-for-Arduino/32262338107.html
Problem1:
When I send byte from PC to Arduino. Nothing happens. Arduino does not receive anything. In this case i upload to Arduino this code:
#include <SoftwareSerial.h>
#include "RS485_protocol.h"
SoftwareSerial rs485 (10, 11); // receive pin, transmit pin
const byte ENABLE_PIN = 3;
void setup()
{
Serial.begin(9600);
rs485.begin (28800);
pinMode (ENABLE_PIN, OUTPUT); // driver output enable
}
void loop()
{
byte buf [1];
byte received = recvMsg (fAvailable, fRead, buf, sizeof (buf));
if (received)
{
Serial.println(buf[0]);
} else {
Serial.println("--");
}
} // end of loop
int fAvailable ()
{
return rs485.available ();
}
int fRead ()
{
return rs485.read ();
}
And open Serial Monitor in Arduino IDE to show received data.
Then I open new instance of Arduino IDE, chose proper USB-to-RS485 COM port and opens it Serial Monitor to send some data.
So in Arduino side Serial Monitor I see only "--" lines. Even when I'm trying to send something in PC side Serial Monitor.
The other problem is:
Vice versa. When i sending some byte from Arduino to PC I receive some odd symbols instead sent byte.
The Arduino code in this case is:
#include <SoftwareSerial.h>
#include "RS485_protocol.h"
SoftwareSerial rs485 (10, 11); // receive pin, transmit pin
const byte ENABLE_PIN = 3;
void setup()
{
rs485.begin (28800);
pinMode (ENABLE_PIN, OUTPUT); // driver output enable
}
void loop()
{
byte msg[1] = {3};
sendMsg(msg);
} // end of loop
void sendMsg(byte msg[])
{
delay (1); // give the master a moment to prepare to receive
digitalWrite (ENABLE_PIN, HIGH); // enable sending
sendMsg (fWrite, msg, 1);
digitalWrite (ENABLE_PIN, LOW); // disable sending
}
void fWrite (const byte what)
{
rs485.write (what);
}
int fAvailable ()
{
return rs485.available ();
}
On the PC side (in the Arduino IDEs Serial Monitor) I receive odd symbols instead "3" symbol.
=======
RS485 converters wired with twisted pare A to A and B to B.
RS485 to TTL converter connected to Arduino properly. (Communication between two arduinos works fine).
Please help.
Example of RS485 :
Using a SN75176 IC.
RE (pin 2) connect to ground (for always reading )
Arduino control only DE PIN for writing data
But PC side problems:
Where bridged DE pins ? (CTS,DTR,RTD if supported)
What is your flow control ? (related #1)
Did you connect any resistor to A, B pin ?<+5V>----[560R]-----(A)----[120R]-----(B)------[560R]------<-5V> So mean line end
Did you filter DE Pin 2 signal (for noise)
A tricks : Use SN75176 on arduino side because this IC a RS232(UART) to (RS485) converter.
Edit : Modbus got 2 type on serial (RTU, ASCII). Dont care RS232/485 differences because different signal, same protocol.
Example packet type:
ASCII : :010300200004+CRC+FE(crc =packet check code, fe=end delimeter)
RTU : \x01\x03\x00\x20\x00\x04\x +CRC
On rtu : every byte need 1.5 char space and without start and end delimeter.
And Modbus node type meaning master and slave.
I hope helpfull.