I'm planning to build a watering replenishing system.Do You think is possible to connect 9 or 10 ultrasonic sensors to one board? (I was thinking about an Arduino 2560).I've read somewhere that there could be problems because of interference signal between the sensors but since I'm a total newbie I don't know.
Cables from the shield will be long about 2 meters (not more) or alternatively I can split 5+5 sensors on 2 distinct boards (always using 2 meters cables) or using a different approach I can use one hc-sr04 for each Arduino Micro (for a total of 10 Micros).
Any suggestion really appreciated!!!
Yes, it is possible to connect ten sensors to a board with 20 I/O pins.
Whether or not the audio signals interfere depends on how they are positioned relative to each other, and how they are triggered.
After doing a little bit of research I've found out that the hc-sr04 sensors are not suitable for my purpose,apparently they're good to measure centimeters (even with the Newping library) while I need to measure millimeters.The US-100 sensors seems more performing and I see they've got a temp.sensor that gives compensated readings.
Now another problem arise:since the us-100 must be operated in serial mode (to benefit of temp.correction) on the tx-rx pins,I'll need 9+9 tx and rx!! Arduino Mega2560 has got only 4+4 so I need 3 boards :o
At this point I see as the only solution to get 9 Arduino Micro or a similar board!
RobertR:
since the us-100 must be operated in serial mode (to benefit of temp.correction)
What makes you believe that?
Because you can read the temperature?
Because the distance can be read in mm?
The US-100 features accurate temperature corrected range detection. It can output the distance in millimeters using a serial data output mode. Alternatively, the distance can be calculated by measuring the amount of time that a digital output is held high.
RobertR:
After doing a little bit of research I've found out that the hc-sr04 sensors are not suitable for my purpose,apparently they're good to measure centimeters (even with the Newping library) while I need to measure millimeters.The US-100 sensors seems more performing and I see they've got a temp.sensor that gives compensated readings.
Now another problem arise:since the us-100 must be operated in serial mode (to benefit of temp.correction) on the tx-rx pins,I'll need 9+9 tx and rx!! Arduino Mega2560 has got only 4+4 so I need 3 boards :o
At this point I see as the only solution to get 9 Arduino Micro or a similar board!
All you need to do is convert to millimeters. Of course, please read the datasheet as it will tell you the effective range of the sensor.
Whandall:
It is temperature compensated, I don’t know the real resolution.
Why do you think it is only temperature compensated if read serially?
My apologies! I’ve read erroneously.It should be always compensated regardless the serial data or the puls width mode.The difference is the following (using serial data):
"To start measuring the distance, output a 0x55 over the serial port and read back the two byte distance in high byte, low byte format. The distance returned is measured in millimeters. Use the following formula to obtain the distance as millimeters:
This module can also output the temperature when using serial output mode. To read the temperature, output a 0x50 byte over the serial port and read back a single temperature byte. The actual temperature is obtained by using the following formula:
Celsius = ByteRead - 45
So at the end I can use 9 of them on a single Mega board using digital pins
