Hi,
after some smaller tutorial project with my arduino uno, I want to use a 5V 134.2 kHZ rfid reader to read animal tags (these are usually working at 134.2 kHz). So I have a reading module similar to this one: 5V RFID Animal Tag Lesemodul Ear Tag Foot Ring Reader EM4305 134.2KHZ Reader cde | eBay I connected the outgoing TX from the module to pin 2 and defined a software serial. And 5V and GND are both connected as well to the corresponding points of my Arduino.
#include <SoftwareSerial.h>
SoftwareSerial RFID(2, 3); // RX and TX
int i=0;
void setup()
{
//pinMode(13,INPUT);
RFID.begin(9600); // start serial to RFID reader
Serial.begin(9600); // start serial to PC
}
void loop()
{
if (RFID.available() > 0)
{
Serial.print("CHECK");
i = RFID.read();
Serial.print(i);
delay(100);
}
}
Unfortunately, there is not any good manual or datasheet for the RFID module. In the description (see screenshot); it just mentions the pins on the module that are 5V, GND and TXD (no RX?). And that the output interface is UART (9600, N, 8, 1). At the moment I am not receiving anything if I hold a 134khz tag close and my serial monitor stays empty. So I am not sure if it is a wiring issue, or a coding issue or both....As said I am rather newbie and thus would appreciate any help. Has anyone worked with such a module?
I've now connected a R232-TLL converter board (MAX3232, https://bit.ly/34AVSPC) between my RFID reading module and my Arduino UNO. Unfortunately, I still don't receive any signal when reading RFID.available() at digital pin 2 which is my SoftwareSerial RX.
What I realized is that the RFID module does not have a RX pin so there is no connection between my Arduino TX --> MAX3232 TLL RX --> MAX3232 R232 TX --> RFID module RX. I am not sure if this is needed?
I also measured the voltage of the R232-TLL converter board at the outgoing TLL TX pin by connecting it to the analog pin A0 on my Arduino (https://www.arduino.cc/en/Tutorial/BuiltInExamples/ReadAnalogVoltage). Here I can measure about 1V when everything (RFID and MAX3232 are powered with 5V).
What I realized is that when everything is connected (both RFID and MAX3232 powered, MAX3232 TLL TX to Arduino RX, RFID TX to MAX3232 R232 RX) the R232 converter gets warm/hot. I'm not sure if that's normal?!
Does anyone have suggestions or ideas how to proceed? I am happy about any help, as this all is very new to me!
The specs for your board state UART which is indicative of TTL signals. However, this can be verified with a magnifying glass and reviewing the ICs on the board. It is difficult to tell in the photo with having no schematic.
I tried to check with the magnifying glass: The smaller IC says something like LM2904 but the larger one has no indication on it at all. Does the information about the LM2904 already help, it seems to be a general purpose op amp...Unfortunately the board does not have any schematic or more specifications about the IC etc.
The issue of whether the board output is R232 or TLL has been solved.... I again connected the board directly to the arduino without the R232-TLL converter and I somehow managed to receive a signal (so TLL). I am not sure exactly what solved the problem, but I rewired everything (so maybe a broken cable before) and what I realized is the the antenna only recognizes my tag if it positioned in appr. 90 degree angle; if the tag is positioned parallel to the antenna nothing is received (which makes technically sense).
So now I just need to get my reading translated into a reasonable tag ID...
