EK-3000I weight measurement to arduino from RS232C to max3232

[rif1]

hey can someone help me?, i got some problem with EK-3000I to arduino, i use rs232 to ttl a.k.a Max3232

for EK-3000i i already set the fuction setup
bps : 2 (baud rate 9600)
prt : 0 ( stream mode)

but serial monitor not showing anything

connection
MAX3232

• TXD to arduino RXD
• RXD to arduino TXD
  -GND to arduino GND
• VCC to arduino 5V

device

• arduino nano
• rs232 to ttl (MAX3232)
• weight measurement EK-3000i

this is my all device

and

this is my simple code

#include <SoftwareSerial.h>
SoftwareSerial scaleSerial(2, 3);

void setup() {
  Serial.begin(9600);
  scaleSerial.begin(9600);
}

void loop() {
    String data = scaleSerial.readString();
    Serial.print("Weght: ");
    Serial.println(data);
}   

thx for someone helping me

[jim-p]

@rif1

EK-3000I

You need a cross-over cable between the scale and the RS232 adaptor.

[rif1]

sorry im not good in english did u mean txd and rxd from scale is reversed?
btw thanks ill try it

[jim-p]

did u mean txd and rxd from scale is reversed?

No i did not.

You need this cable to connect them:

A cross over cable also called null modem cable crosses all the connections

[rif1]

oh i understand now, but i didnt have that cable maybe i should wait, thanks for help ill back after i bought that

@jim-p

A cross over cable also called null modem cable crosses all the connections

I moved your topic to an appropriate forum category @rif1.

In the future, when creating a topic please take some time to pick the forum category that best suits the subject of your topic. There is an "About the _____ category" topic at the top of each category that explains its purpose.

This is an important part of responsible forum usage, as explained in the "How to get the best out of this forum" guide. The guide contains a lot of other useful information. Please read it.

Thanks in advance for your cooperation.

[Paul_KD7HB]

@rif1

oh i understand now, but i didnt have that cable maybe i should wait, thanks for help ill back after i bought that

Or, you could learn how to make cables like that.

[jim-p]

Thes are also small null modem adaptors that you can put between the scale and RS232 adaptor.

Just make sure it says null modem or cross over and it is male on one end and female on the other end.

[rif1]

by the way i have a question, MAX3232 is just need TXD,RXD and GND am i wrong?
because my TTL module just connect 3 pin to the chip
and FYI also after i open the casing of my EK-3000i i found MAX232CWE chip

[JohnLincoln]

@rif1

I have a question, MAX3232 is just need TXD,RXD and GND am i wrong?

I think that you are correct, and that only those 3 connections are required.

[jim-p]

I think this is the manual for the scale
ekw-i.pdf (1.7 MB)

It shows only RX and TX being used. So you could just try using some male/female jumpers to cross pins 2 an 3 on the DB9 connectors. You also need to connect pin 5 to pin 5 which is the ground.

[JohnLincoln]

I have written some code to simulate the data sent by the scale.
See page 25 of the manual for details

I will use it to test your code.

unsigned long previousMillis = 0;
int interval = 100;

void setup() {
  Serial1.begin(9600);
}

void loop() {
  unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= interval) {
    previousMillis = previousMillis + interval;

    Serial1.println("ST,+00123.5  g");
  }
}

I can use Mega 2560 to sent the data, and receive it on a Uno.
I have a lead that I know connects the two Arduinos RS232 converters correctly

[rif1]

i already use an cable jumper
as i tested using multimeter pin 4 from EK-3000i is stutering, and from arduino its still hasnt show anything

@jim-p

It shows only RX and TX being used.

[jim-p]

You can try doing this with jumper wires.

[jim-p]

No screen shots of code please.
To post your code, in the IDE click on Edit, then Copy for Forum, that will copy your code. Then come back here and just do a paste.

Sometime just sticking wires in the connector holes does not make a good connection.

[rif1]

@jim-p

You can try doing this with jumper wires.

okay gimme a second ill try that

@jim-p

No screen shots please.
To post your code, in the IDE click on Edit

and sorry its my first time using arduino forum

[rif1]

its still has no result

but FYI when i connect it directly to arduino it show like this

Weght: V�Z������6���1��V�Z������6���1��V�Z������6���1��V�Z������6���1��V�Z������6���1��V�Z������6���1��V�Z������6���1��V�Z������6���1��V�Z������6���1��V�Z������6���1��V�Z������6���1��V�Z������6���1��V�Z������6뿿1��V�Z������6뿿1��V�Z������6뿿1��
Weght: 
Weght: 
Weght: 

[jim-p]

@rif1

MAX3232

• TXD to arduino RXD
• RXD to arduino TXD
  -GND to arduino GND
• VCC to arduino 5V

That is wrong.
The marking on the MAX3232 adaptor are confusing.
You need to connect like this:
TXD to TXD
RXD to RXD

[rif1]

i twist the pin 3 for TXD and 2 for RXD
and try pin 2 for TXD and 3 for RXD
but still not showing anything

#include <SoftwareSerial.h>
SoftwareSerial scaleSerial(3, 2);

void setup() {
  Serial.begin(9600);
  scaleSerial.begin(9600);
}

void loop() {
    String data = scaleSerial.readString();
    Serial.print("Weght: ");
    Serial.println(data);
}   

is my modue has some trouble or wrong module?
cuz i got some signal using an multitester as the led blinking fast when check txd from EK-3000i

[rif1]

wait i got it
my cable a little loose and after i fix it i got the byte

Weght: 
Weght: 
Weght: 
Weght: ST,-000000.5  g
?
?
?
?