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Topic: Using Uno w/ Dattalogging Shield to record Precision Barometer measurements (Read 802 times) previous topic - next topic

nikoman95

This is my first Arduino project so I'm not completely sure about what I'm doing. I'm trying to use an Arduino Uno with a Data-logging shield and an SD card to record measurements from a DPI 740 Precision Pressure Indicator (made by OMEGA) onto the SD card every 5 minutes for up to 8 hours at a time. I'm using a 6-pin LEMO type adapter cable (with only 5 wires being used) to connect the Arduino to the barometer. The issue is that I don't know to which pins I should solder the wires onto the Arduino, and I can't find a code similar enough to my project to use.

The Barometer has a 9600 Baud rate, 8 data bits, 1 stop bit, no parity, and no handshaking.
The 5 wires used by the 6-pin LEMO cable are labeled:
1. RxD input
2. CTS input
3. GND
4. RTS output
5. TxD output

If anyone can help me complete this project or point me in the direction of helpful information I would be greatly appreciative. Tell me if more information is needed.

http://imageshack.com/a/img801/7205/3dal.jpg

michinyon

For that,  you should only need 3 wires.   Connect the ground to the arduino ground.

If they are correctly labelled,  connect the Tx of the device to the Rx of the arduino,    and the Rx of the device to the Tx of the arduino.

If you are only going to have the arduino listen to the device,   and don't need to send any setup string or data,   then you don't need the last one.

You also need to consider that some devices are labelled wrongly,   and you actually might need to connect the tx to tx and the rx to rx.

michinyon


nikoman95

Thank you, that is very helpful :)

Its powered by a 9v battery pack.

Chagrin

Isn't there a concern that this is RS232 and not TTL? The higher voltage of RS232 will kill your Arduino.

https://www.sparkfun.com/tutorials/215

nikoman95

I hadn't thought of that. Should I purchase a RS-232 shifter or Max-232 (found on your link), or a RS-232 Shield to fix the issue?

Chagrin


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