Connection problem MAX202 RS232 to TTL Converter MKR1000

Help & Support Robot Parts
1

I’m using the ‘MAX202 RS232 to TTL Converter’ on a Arduino MKR1000 to send RS-232 to a LCD display. (https://www.dfrobot.com/product-196.html).

Wiring:

GRND MKR1000 – GND TTL connector
5V MKR1000 - 5V TTL connector
13 RX MKR1000 - TX TTL connector
14 TX MKR1000 - RX TTL connector

TX TTL - TX RS232 LCD
RX TTL - RX RS232 LCD

On the arduino I’ve used the Serial1 with baudrate 9600. The TTL connector is powered, however I don’t see any activity on RX of the TTL connector. Can it be that the MKR1000 is not supported for the TTL connector? To do with lower voltages 3.8 instead of 5V signals?

I’m lost for the moment.

2

With no activity I mean there is no visual indication of activity on the TTL connector.
With a multimeter there is a voltage (3+ V) on the RX of the TTL connector, I don’t have an oscillator to measure.

3

I’ve done a test with an arduino uno also

#include <SoftwareSerial.h>
SoftwareSerial mySerial(10, 11); //rx tx
…
mySerial.begin(9600);
…
mySerial.println(“hello”);
…

Between the TTL connector and the RS232 device I only connect RX and TX
Nothing happens.

4

issue solved. Was not related to the Arduino type.

wiring was not ok
13 RX MKR1000 - RX TTL connector
14 TX MKR1000 - TX TTL connector

  • wiring missing:
    GND TTL - COM RS232 LCD