Dear fellow people compensating time for not having a girlfriend, {just joking, I'm even married} I'm dealing with a problem and desperately in need for help right now. I'm opening a mushroom farm and could get my hands cheaply on a high quality CO2 measurement device (VAISALA GMT 220) which works …

Please edit your post and insert code tags! Both SoftwareSerial and HardwareSerial classes have their interal buffers so you definitely don't need to add more buffers. So your sketch can be written much shorter: #include <SoftwareSerial.h> SoftwareSerial O2_serial(10, 11); void setup() { Seri…

Hi Pylon and Hammi, first of all thanks for your reply and the effort! It's actually kind of a shitty situation since I could really benefit from the Sensor, I'm building up a mushroom farm and without the CO2 sensor it's kind of difficult to know if I get the right amount of Air exchange. Other CO…

Manual vaisala-gmt220-userguide-english.pdf (724 KB) vaisala-gmt220-userguide-english.pdf (724 KB)

Your manual never says the communication is RS-232. It does say an adapter is necessary to connect to a PC, which leads one to believe the device uses TTL levels. You can easily verify by powering the device and measuring the TX voltage to ground. Paul

since the previous Owner already successfully used the sensor with an Arduino I don't think voltage is the problem, I need a simple code which let's me Send a command to the device and receive the answer.

For 200$ it's possible to buy a data cable and use windows hyper terminal to send commands via prompt. So there must be a way to send a simple Command like "DISP 2" and receive the answer of for example "1100"

Try this one [image] Adding More Serial Ports to your board. | Arduino Documentation With the help of the SoftwareSerial library, it is possible to create additional software serial ports on your Arduino board. change these mySerial.begin(4800); mySerial…

Remember to connect Tx of the sensor to (SoftwareSerial's) Rx of the Arduino and the other way around. After all what the sensor transmits (Tx) the Arduino has to receive (Rx).

The attached pictures show a Mega2560 clone and not an UNO! Is that your setup or the setup of the former owner? Using SoftwareSerial on a Mega2560 doesn't make sense, the board has 4 hardware serial interfaces.

VAISALA CO2 Sensor - Serial Comm

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hammy June 8, 2019, 6:46am 3

Rs232 operates at different voltage levels to the Mega serial port - do you have level shifting components or an rs232 adapter lead ?

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VAISALA CO2 Sensor - Serial Comm

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