Sorry but I am relatively new to Arduino. I am wanting to transmit code in ascii to a device operating at 9600 baud and want to graph the example back in a graph form ex. a battery volt. I am having trouble figuring which serial protocol to use and which pins to use. The device transmits at a 5 volt signal and has a rj 45 plug on it (phone plug with 6 wires). Any help starting would be appreciated. Thanks in advance.
If you are new you should start spending a day or two at the tutorial section of arduino.cc There is a lot to learn including Serial communication.
Serial uses pin 0 and 1 and a minimal sketch that captures a string from a device looks like
char buffer[80];
int idx =0;
void setup()
{
Serial.begin(9600);
}
void loop()
{
if (Serial.available() >0)
{
char c = Serial.read();
buffer[idx] = c;
if (c == ';') // check for a ;
{
buffer[idx] = 0; // end the string
// buffer now contains a string
// you can now do something with the read data
idx = 0;
}
else
{
idx++;
if (idx==80) idx=0; // prevent overflow.
}
}
// do other things here
}
Which pins should I use for transmitting and receiving data? Do I need to include the softwareserial library?
I was originally confused by the software serial port versus hardware serial port. I was trying to power up the arduino and transmit on the hardware port. I am still confused about the ascii table of transmission. I am wanting to send a command of 01 voltage. 01 meaning the battery device number.
Which pins should I use for transmitting and receiving data?
Depends on whether you want to tie up the hardware serial port (pins 0 and 1) or not.
Do I need to include the softwareserial library?
Ditto.
I am wanting to send a command of 01 voltage.
You send data to the serial port. If the data that you send is understood by the receiver to be a command, the receiver will take some action. Sending a "command of 01 voltage" means nothing to me. What does the device you are trying to talk to expect to see for a "command of 01 voltage"? What does "a command of 01 voltage" even mean, anyway?
Here is the full definition of the command.
A command starts with the bus address in ascii decimal (ie: 0 to 254). These are
followed by the specific command to be executed. Since address 99 can be a
broadcast command, in order to talk to unit 99 the address must be preceded with a 0
as in “099”.
voltage (v.)
Full Syntax: voltage
Minimum Syntax: v.
Broadcast Command: no
Example:
Command: 1v.
Reply: 01V 3.338V
Need some guidance please. I got the communication working between the arduino serial monitor and a bms device(aka a battery device) using one of the commands set by the manufacturer. The command is 001mi.
I am wanting to connect a touchscreen an arduino uno and the bms card together. The touchscreen as master the uno as a slave and the bms card as a slave. I am wanting to keep the digital pins 0 and 1 open for the serial monitor. Here is a statement of the communication protocol from the vendor. The signaling is half duplex (party line) async like RS232, but with a different hardware interface. Undriven, (space), the two lines are between 10 and 15V apart, and driven, (mark) they are about 2V apart. There is no "ground" reference. One advantage of this is that you can use a normal terminal or terminal emulator program to talk to the Bus devices: 9600 Baud, 8 bits, no parity, 2 stop bits. "01mi." followed by a carriage return.
#include <SoftwareSerial.h>
SoftwareSerial bmsSerial(2, 3);
void setup()
{
Serial.begin(9600);
Serial.println("001mi.");
// set the data rate for the SoftwareSerial port
bmsSerial.begin(9600);
bmsSerial.println("001mi.");
}
void loop() // run over and over
{
if (bmsSerial.available())
Serial.write(bmsSerial.read());
if (Serial.available())
bmsSerial.write(Serial.read());
}
E-CarNut:
I am wanting to connect a touchscreen an arduino uno and the bms card together. The touchscreen as master the uno as a slave and the bms card as a slave.
I don't know what that means. Are you saying you have a touchscreen with a serial interface? What is controlling the display on that touchscreen? What is handling the input from it? What do 'master' and 'slave' mean in this context? You're talking about bus mastering? If so, what type of bus? There are some multidrop serial standards, but I have no idea whether that's what you're trying to do here. Perhaps you'd better step back and describe the problem and how you're trying to solve it.
My bad the display would be tallking to the arduino via serial. The display would be sending(only during user tft input) and receiving to display bar graphs. The Arduino would be continuously sending commands to the bms modules like minimum volts,maximum volts,voltage etc. and receiving the results back from the bms modules to display on the lcd tft display. The bms modules are set up to just sit there like a slave until a command is received. However when a fault occurs it sends the the fault(like low voltage) back to the Arduino to be processed by the arduino and a flag displayed in the display(low voltage cell #1) for example. I hope this clears up the concept. Right now I can't get the Arduino to talk to the bms modules. I can however talk to the bms modules and receive data back using the arduino serial monitor and using the carriage return tab on the bottom. But am not having any luck with the program aspect.
Still having troubles.