NXC: can't read Dexter pressure sensor values

[mightor]

Then just stick to TOUCH. I doubt John will change this behaviour as it would make sensor readings in the EFW incompatible with the standard one. It would be better to create a new sensor type that doesn't cook the results.

- Xander

[HaWe]

TOUCH is not good:
1st, it's other way round as LIGHT_INACTIVE
2nd, more important: it produces only raw values between 40 and 18 (in the range of 0-1023).

I actually doubt that these are the correct values, chiefly because _LIGHT or _LIGHT_INACTIVE give constant 0 or 1023 (while the sound sensor in both cases gives correct values)

Have you got the same 40 to 18 range with your own driver?

[mightor]

You should be using SensorRaw if you want the proper values. I was getting values in the 400 range at normal pressure in NXC.

- Xander

[HaWe]

what is SENSOR_RAW? a sensor type?
as a mode I'm alread using
SetSensorMode(S2, SENSOR_MODE_RAW);

I tried now
SensorRaw(1);
instead of
SetSensorMode(S2, SENSOR_MODE_RAW);

but I'm getting only constantly 0.
But also attaching a sounssensor instead I only get constantly 0 with this.

(@John: rather weird those sensor readings , types and modes in NXC. Please make it better and more logical!)

[HaWe]

ps now I think I got it:

SetSensorType(1, SENSOR_TYPE_TOUCH);
SetSensorMode(1, SENSOR_MODE_RAW);
value=SensorRaw(1);

But in this case I only get values from 40...18


([Goodness], what a mess those NXC sensor readings! If once configured as SENSOR_MODE_RAW: why then not read as SensorValue but SensorRaw??? )

[mightor]

The firmware design is LEGO's, not John's So blame them for the messed up sensor modes.

Did you try the program I pasted? It works for me with my DI pressure sensor. I have the 35PSI version.

- Xander

[HaWe]

OK: sorry: what a mess with those Lego sensor readings!
Let NXC become better!

(I got the 70 psi version)

What posted code?

[HaWe]

do you mean this:

Code: Select all

    int val;
    float pressure;

    task main(){
      //SetSensorType(S2, SENSOR_TYPE_TOUCH);
      SetSensorType(S2, SENSOR_TYPE_LIGHT);
      //SetSensorType(S2, SENSOR_TYPE_LIGHT_ACTIVE);
      SetSensorMode(S2, SENSOR_MODE_RAW);

      while(true) {
         val = SensorRaw(S2);
         pressure = ((val / 1023)  - 0.04) / 0.0018;  // Vout = ((val * DPRESS_VREF) / 1023);

         printf("raw=%5d", val);
         //printf("hPa=%5.1f", pressure);  // alrenatively show raw or pressure

         Wait(10);
      }
    }

with this I get constantly 233-234

[mightor]

And with the sensor configured as a TOUCH sensor?

- Xander

[HaWe]

46...18