How to send ASCII command to sensor and read out answer

Other Hardware Sensors
1

Hi all,

I have an inclinometer sensor which I need to read out with arduino. If the sensor gets the command get---x it sends the value over serial connection.

With the serial monitor it works well when I send get---x. Now I'd like to do that in a function in may sketch like void getdata(). When I call that function the sensor should send the value.

PC is connected to arduino Serial and sensor is connected to Serial2 on my Mega.

How can I send that command in my function like the serial monitor does it? The sensor should send a 9byte string as answer like ±xxx.xxx which I need to read back on Serial to the PC.

Could someone help with a code snippet or give me a hint how to do that?

I use this sketch with my serial monitor that works

void setup() {
	// initialize both serial ports:
	Serial.begin(38400);
	Serial2.begin(38400);
}

void loop() {
	// read from port 1, send to port 0:
	if (Serial2.available()) {
		int inByte = Serial1.read();
		Serial.write(inByte);
	}

	// read from port 0, send to port 1:
	if (Serial.available()) {
		int inByte = Serial.read();
		Serial2.write(inByte);
	}
}
2

Take a look at Robin2's excellent serial handling basics tutorial

3

Thanks for the hint

Joe

4

You choose not to identify the particular sensor you have... Any reason for keeping that a secret?

5

Hi it's not a secret at all. It's from leveldevelopments model HPS-05-1-232
https://www.leveldevelopments.com/products/inclinometers/inclinometer-sensors/single-axis-inclinometer-sensors/hps-series/hps-05-1-232-precision-inclinometer-single-axis-5-rs232-output/

Data sheet

I read through the named basic serial tutorial but couldn't find a real solution.

My code for now

void setup()
{
 Serial.begin(38400);
 Serial2.begin(38400);
}

void loop()
{
 Serial2.write("get---x");
 while (Serial2.available()) {
 int inByte = Serial2.read();
 Serial.write(inByte);
 }
 Serial.println();
 delay(1000);
 Serial2.write("gettemp");
 while (Serial2.available()) {
 int inByte = Serial2.read();
 Serial.write(inByte);
 }
 Serial.println();
 delay(1000);
}

This works but brings sporadic failures in the sent values.

Has anybody a better solution, maybe readout the exact number of sent chars?

6

Any solution not involving delay(1000); would be an improvement, surely?

7

The delay is just for testing. I will not use the code in the loop in the end I will create a function to get the sensor value.

8

Having several example of the returned results would help but have you tried parseFloat to see if it works?
It might stumble if you have a leading + character but then you could maybe read the results into a buffer using readBytesUntil and then start at the second character.