Wiring Ultrasonic sensor w/ temp compensator

The temperature compensation sensor for the Maxbotix sensor doesn’t interact with the Mayfly at all. It’s connected directly to the ultrasonic sensor’s pin #1, so the Mayfly doesn’t need to know anything about it. All the Mayfly does is capture the serial data that comes from the sensor’s data pin.

I’ll be away from my desk most of the day doing remote sensor station installation, but when I get back to my lab I’ll try to take some pictures of the wiring setup for my ultrasonic stations and post those along with a description of how to hook up the cables.

You can try:
https://www.maxbotix.com/Ultrasonic_Sensors/MB7955.htm
https://www.maxbotix.com/Ultrasonic_Sensors/MB7389.htm
for the data sheets.

Hope it helps.

The red cable from the MaxTemp goes to pin 1 on the MaxSonar. The shield (yellow) and black cables from the MaxTemp both go to pin 7 on the MaxSonar. Pin 7 on the MaxSonar is also connected to ground (black) from the grove, so you’ll be shoving three wires into the MaxSonar screw terminal at Pin 7. Pin 6 on the MaxSonar goes to Vcc (red on the grove). Pin 5 on the MaxSonar goes to D2/white on the grove, if you want to use pin 5 on the Mayfly to receive data.

In your data sketch, you then need to set up an instance of SoftwareSerial with the Rx set as pin 5. Then you want to use the parseInt() function to capture the data from the MaxSonar. (But throw away the first 6 lines from the MaxSonar after power-up, because it sends out a header before sending out data.) There’s an example sketch here: https://github.com/EnviroDIY/EnviroDIY_Mayfly_Logger/blob/master/examples/mayfly_sonar/mayfly_sonar.ino

You can also use the ModularSensors library (https://github.com/EnviroDIY/ModularSensors) with the MaxSonar, if you’d prefer.

I’m sorry for the library download trouble! How are you trying to download them? The easiest way is to get all the libraries for the Arduino IDE is pull them all together from the libraries repo: https://github.com/EnviroDIY/Libraries. If you scroll down, there are instructions for the Arduino IDE and PlatformIO. This will probably pull in some other libraries that you aren’t interested in, but they’re very small files so it shouldn’t be a problem.

Hi all,

I just wired up a temp compensation on MB7389, and after I dumped everything and re-cloned the modular library master branch (managed through GitHub Desktop) after the re-clone it worked for me.

This example sketch that Sara recommended above also seems to work ok (in pin 5).
https://github.com/EnviroDIY/EnviroDIY_Mayfly_Logger/blob/master/examples/mayfly_sonar/mayfly_sonar.ino

The sonar test from the modular library master branch (in pin 11) returns a distance and indicates “good result found” and the response matches the distance I’m measuring.
https://github.com/EnviroDIY/ModularSensors/blob/master/sensor_tests/sonar_test/sonar_test.ino

The single sensor example from the modular library master branch (in pin 11) oscillates between returning a good distance and one that is 6 meters further than reality.
https://github.com/EnviroDIY/ModularSensors/blob/master/examples/single_sensor/single_sensor.ino

After commenting out several of the extra sensors, I was also able to run it on the multisensor print sketch.
https://github.com/EnviroDIY/ModularSensors/blob/master/examples/multisensor_print/multisensor_print.ino

I have attached a photo of my wiring. @srgdamiano, great work on the modular library!

I’m sorry, I’ll have to look into why you’re getting some values that are too high.

Apologies for resurrecting an old thread, but it is exactly on-topic for my situation.

I’m confused about wiring the MaxTemp. The ModularSensors documentation says to connect the red wire from MaxTemp to the MaxSonar’s pin 6 (V+). However, the MaxBotix datasheet shows no connection of the MaxTemp to V+. Likewise, @fisherba Beth’s photo above shows there are only 2 connections from MaxTemp:  one to the MaxSonar’s pin 1 (via yellow Grove wire) and the other to pin 7, GND (black wire). Beth said her circuit works, so @srgdamiano, is the ModularSensors doc incorrect?

Thanks!
Matt

Follow the datasheet.  If the docs for ModularSensors disagree they’re probably outdated or just wrong.  I’m s..l..o..w..l..y.. working through the documentation and transferring to a Doxygen based documentation set here:  https://envirodiy.github.io/ModularSensors/getting_started.html.  But I’ll add this to my list of bits to fix.

OK, thanks Sara. I really like the look and layout of the new Doxygen docs. Thanks for all your efforts!

Matt

I’ve probably done something dumb in my code, but can’t see what it is, so I could use another set of eyes on it…

I’ve got a MaxBotix MB7589 SCXL-MaxSonar-WRMT and have it communicating via NeoSWSerial on pin 7. Using the single_sensor.ino example, it works fine. Now I’m trying to integrate it a logging sketch, based on DRWI_NoCellular.ino, and I never get any readings displayed nor written to the SD card. Code is attached. If I comment the sonar_range variable out of the variableList, it works, and the remaining variables get successfully logged.

Here is the debug output after turning on the debug flag in MaxBotixSonar.h:

Thanks,
Matt

I think my code must not be catching the interrupt properly. It doesn’t get beyond this line in MaxBotixSonar.cpp:

I am able to get it working by using AltSoftSerial (Rx on pin 6), but am unable to get NeoSWSerial to read from the MaxBotix sensor.

Any help is appreciated.

Thanks,
Matt

Any ideas why AltSoftSerial works here, but NeoSWSerial doesn’t?

Oops, sorry that I missed this.

Are you using slashDevin’s original NeoSWSerial or are you using my fork? (It’s in SRGDamia1, not EnviroDIY.)  The original didn’t implement the peek function which would cause it to fail.

Yep, that was it. When I didn’t find the library in EnviroDIY, I just grabbed it from slashdevin’s original. Now that I have your fork of NeoSWSerial, it works. Thanks!