I'm outputting a data stream on serial1. I can read it as expected using a terminal program connected via serial cable connect to the DB9 connector on Converter Module - MAX3232 (232-ttl). but when connect to a device that only sees 232 input the message is not recognized. Am i confused that the 232 to ttl converter does not output 232 level? I try to find a converter that is ttl to serial but they all say 232 to ttl. Am i using the wrong level converter?
Did you connect TX, RX, and GND? I can't tell from your pencil sketch.
"A device"
What is the device?
Your unknown device may need to be told it is connected to something by using other RS-232 pins.
Or @btoothill may have to adjust the serial settings certainly matching the baud rate. Parity and stop bits and stuff might wanna match also.
Does the documentation for the device state what it expects to see?
a7
i have selected the correct baud rate and other data transfer settings (9600 8,n,1)
I'm wondering if the data stream I'm sending is the correct level. My device requires rs232 and I believe from serial1 the Arduino is sending TTL. I connected a 232 to ttl converter. ( WWZMDiB RS232 to TTL Converter Module Using MAX3232 chip) to the Arduino board (2560), pins 18 and 19, and connect my serial cable to the db9 connector on the converter. I'm wondering since the converter says rs232 to TTL . is it doing what i want? I really need TTL to 232, or is this just a matter of semantics or do i really need a TTL to 232 converter. I tested the pins out on the db9 connector and I don't get anything above 3v., shouldn't I being seeing ~12v out for the 232 level? thanks!!
You said it work with a terminal program but not with this "device"
So it seem the problem is with this "device"
You still have not told us what this "device" is.
the device is a Calamp LMU 3641. cellular data modem used in a GPS tracking device. Im thinking as I said above that i think the problem may be in the data level. The LMU requires a rs232 level data stream, and im not sure that is whait I am putting out. I know serial1 put out ttl level and not sure my converter i doing what i expect
What you need is a crossover cable also called a null modem cable. It basically swaps the connections on pins 2 and 3 on the DB9 connector.
I have a mega 2560
*I am connecting the TX pin of the MAX3232 module to the RX pin on the Arduino.
*and connecting the RX pin of the MAX3232 module to the TX pin on the Arduino.
Do i still need the null modem cable?
If those connections worked when you used the terminal program then yes you need a crossover cable.
sorry I made an error it only works in my terminal program when i connect rx to rx and tx to tx
Then keep RX to RX and TX to TX and use a null modem cable.
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