Go Down

Topic: i2c Pressure Sensor (Read 26270 times) previous topic - next topic

mem

Driving the inputs .7 volts higher than the Vcc voltage will damage some chips, I don't know how sensitive this particular device is.  

PM me if you want to send your HP03 to me so I can try it on my test rig.




wlwl

Hi, mem. I want to use your hp03.pde to make my project. But my board is nano . I think something must be changed in hp03.pde or more. But I am a newbie in C/C++. Can you help me for that?
Best regard.

wlwl

mem

Hi wlwl, I don't use the Nano but would think it should work just like the full size Arduino boards I do use. Why do you think something needs changing?

wlwl

Oh,thanks your notice. Let  me test it in nano! ;) ;)

ricarDOGS

Thanks, Mem.

I´m using IRF3205 and 10K resistors, but i dont get data. Just this:


Error getting HP03 calibration, check sensor connection

pressure 1100

  Altitude, Meters = -698.2

  Altitude, Feet  = -2291.0

pressure 1050

  Altitude, Meters = -301.5

  Altitude, Feet  = -989.0
.
.
.
.
.

pressure 350

  Altitude, Meters = 8117.2

  Altitude, Feet  = 26631.0

Error getting HP03 data, check sensor connection

Error getting HP03 data, check sensor connection

Error getting HP03 data, check s


pin 11 is a resitor voltage??  i used   R1=1.8K  and R2=3.3K and this conected to MCLK.  It´s Ok???

Analog 3 is conected to XCLR with a 10K resitor??

what´s wrong?  i bought a new sensor.
thanks.


ricarDOGS

the reisitor between 5V and Drain aren´t conected. I corrected this, but now when starts the serial comunication (19200 or other)  nothing happens. only black screen all the time.

again, whats wrong????

thanks.

mem

#51
Jul 13, 2009, 10:35 am Last Edit: Jul 13, 2009, 10:37 am by mem Reason: 1
ricarDOGS, its very difficult to debug something like this remotely.  Because there is not much explanation on how to connect things up, it's likely that the problem lies somewhere there. Perhaps if you can take a clear picture of your wiring it may be possible to see if something is amiss.

Do you have any previous experience with interfacing 3.3v to 5v logic levels? Did any of the HP03 pins get connected directly to an arduino pin or 5 volts when you first connected things up?

ricarDOGS


mem

That looks very much like the circuit on the board I made. I will see if I can find the actual circuit diagram I used and will double check and let you know.

By any chance, did you apply +5 volts to any of the HP03 pins, I hope the module is not damaged.


ricarDOGS

I conected like circuit, but when you confirme if its right, i´ll buy another sensor, just to be sure.Again, thanks.

mem

#55
Jul 15, 2009, 10:04 am Last Edit: Jul 15, 2009, 10:06 am by mem Reason: 1
That looks similar to what I did. Here is my schematic so you can double check :


Its difficult for me to tell from your diagram but note that the drains are connected to the Arduino, the sources to the sensor.

For the voltage divider resistors (R5-R8) I used 2.2k on both sides but your values are good.
The other resistors were 8.2k but 10k just as good.

Note I have a 0.1 decoupling capacitor across the 3.3v line - may not be necessary but its best to use one.

mem

#56
Jul 15, 2009, 10:50 am Last Edit: Jul 15, 2009, 02:04 pm by mem Reason: 1
Here is a board layout suitable for building on stripboard that I used to make the shield I posted earlier.



see: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1223819446/43#43

ricarDOGS

Ok, it´s the same circuit. Surely the sensor was damaged.

i´m using IRF3205 or SUP85N06 instead of 2n7000, it doesn't matter ??

R1=R2=R3=R4=8.2K??
R5=R6=R7=R8=2.2K??

Anyway, i´ll buy another sensor and tell you what happens.Thanks.

mem

I would think most any N channel FET would work.

Yes, those are my resistor values but yours are just as good.

ricarDOGS

I changed BS170 instead of IRF3205 and now serial communication starts  correctly, however the pressure and altitude change constantly, i don´t know the real values in my city. But the temperature is  30.5 degrees and a LM35 says 28.1 degrees. These 2 degrees of difenrence are normal?? or the sensor was damaged?? thanks.

Go Up