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Member Since: August 22, 2011

Country: United States



Engineer by day, bboy by night.


Worm Tank Crew

Blowup Kingz


Delta Chi Fraternity Inc.


Electrical & Computer Engineering, Dec. 2011

College of Engineering and Applied Science

University of Colorado at Boulder





  • ——————– Tech Support Tips/Troubleshooting/Common Issues ——————–

    “RS232” Output and Inverting Signal w/ Hardware

    If the ultrasonic range finder is outputting an inverting signal with the voltage level based on Vcc, you could just use an inverting circuit using a transistor to invert the signal. This is not a standard RS232 that uses +/-12V. Try looking at this section under Applications I: Switches – Digital Logic | Inverter [ https://learn.sparkfun.com/tutorials/transistors#applications-i-switches ] or article about the Logic NOT Gate [ http://www.electronics-tutorials.ws/logic/logic_4.html ]. The example used a NPN transistor. We have a few NPN transistors in our catalog => [ https://www.sparkfun.com/search/results?term=npn+transistor ]. 2N3904 should do the job.

    Doing a quick test using a retired NPN transistor from our storefront, I was able to get it working based on the circuit using a RedBoard Programmed with Arduino. I was using an Arduino so Vcc in my circuit was 5V. Since it’s basically two diodes within the transistor, you will want to use resistors to limit the current. I just used two 330Ohm resistors just like I was turning on an LED. You probably do not need to do this but the values might need to be adjusted when using it at higher speeds or if the transistor is not fully turning ON/OFF. Testing with a multimeter, it worked as expected. An input of 5V would result in 0V (logic LOW) on the output since the transistor was turning on. With an input of 0V, the transistor would not be conducting so the output would be held HIGH at 5V. Using an Arduino serial passthrough for further testing, I was able to view the ultrasonic sensor’s output data without any problems.

    “RS232” Output and Inverting w/ Software

    Otherwise, you could be clever in writing your code to store the value and possibly apply some sort of logical NOT operation. In Arduino, there is a special feature using software serial that inverts the signal by setting a parameter to TRUE. [ “Signal Inversion” – http://arduiniana.org/libraries/newsoftserial/ and “Software Serial Constructor” – https://www.arduino.cc/en/Reference/SoftwareSerialConstructor ]. There was someone in the Arduino forums that provided example code to invert the output, parse the data, and output it through the serial monitor here [ User “Goldthing” - http://forum.arduino.cc/index.php?topic=114808.msg864009#msg864009 ].

    Connecting Ultrasonic Sensor to Raspberry Pi

    There is a tutorial from MaxBotix that shows you how to connect ultrasonic sensors to Raspberry Pis => [ http://www.maxbotix.com/Raspberry-Pi-with-Ultrasonic-Sensors-144/ ]. If the ultrasonic range finder’s output serial output is “ RS232 ” like the sensors listed under “Ultrasonic Sensors that Require an Inverter” , this indicates that the signal is basically an inverted output with the voltage level based on Vcc.

    Therefore, you would need to follow the tutorial and use a serial inverter in order to use it with the Raspberry Pi. If you are using a Raspberry Pi an NPN transistor, Vcc should be 3.3V since the Pi uses a 3.3V system. Here’s another example using a PNP transistor [ https://github.com/simonmonk/raspirobotboard/wiki/Rangefinder-Adapter ] for the Raspberry Pi.

  • ——————– Tech Support Tips/Troubleshooting/Common Issues ——————–

    States.h File

    Make sure that the “States.h” file in the same folder as the CloudCloud.ino [ https://github.com/sparkfun/IoT_CloudCloud/tree/570fda603d4ebe0294ab029a0ca8a9a0341f6045/Thing/CloudCloud ]. Otherwise, the code will not recognize certain variables and functions that are defined when the code compiles.

  • ——————– Tech Support Tips/Troubleshooting/Common Issues ——————–

    Orientation of the Header

    This is a type A connector as indicated in the datasheet.

  • ——————– Tech Support Tips/Troubleshooting/Common Issues ——————–

    Common Anode LED

    The board is populated with a common anode LED. You would want to attach the voltage input to the “+” pin. To light the LED, the R, G, and B pins need to be each grounded individually to work.

  • ——————– Tech Support Tips/Troubleshooting/Common Issues ——————–

    Needle Sizes

    The bigger needles are easier and faster to thread than the smaller ones. Depend on the how many layers of material you are using and the part you are attaching, it might be better to use the smaller needle. For example, if you are trying to secure the snap assortment pack [ https://www.sparkfun.com/products/11347 ] to a piece of fabric, it would be better to use the smaller needle because of the diameter of the mounting holes.

  • ——————– Tech Support Tips/Troubleshooting/Common Issues ——————–


    I would assume that there is no polarity since there is just a coil inside the geophone. There is nothing in the datasheet that indicates that there is a polarity marker. I couldn’t find any information specifically about the pinouts from the examples.

    Testing the geophone under a oscillscope, it did not seem to have a polarity and it was just producing an AC signal like an analog sensor. If I added a vibration with the sensor upside down or right-side-up , it would provide the same spike in voltage. Even connecting the probe pins on either side did not seem to matter. Depending on how I provided the vibration and how the probe pins were connected, the spike might be inverted relative to the setup.

    Going Further

  • ——————– Tech Support Tips/Troubleshooting/Common Issues ——————–


    If you have not checked out the MicroView kit’s tutorials, try checking out the online tutorials for the kit:


    Going Further

    Try using a ESP8266, Logic Level Converter, and a Serial Protocol to display the current weather on a MicroView. This tutorial might be of some use using Yahoo’s Weather API:

  • ——————– Tech Support Tips/Troubleshooting/Common Issues ——————–

    Dimensions of the LED Light Bar

    The dimensions of the LED Light Bar (White) are listed below including a drawing:

    • width = 3.6" (92mm)
    • length = 0.59" (15mm)
    • Mounting Hole OD is 0.15" (3.8mm)

    Dimensions of the LED Light Bar - White (SMD) [COM-12014]

  • ——————– Tech Support Tips/Troubleshooting/Common Issues ——————–

    Default Characters and Lines for Serial Enabled Backpack

    Looking at the production test procedures for this board, the default is set to the 16 characters and 2 lines . If you are using a 20x4, you just need to send a command byte ( 0x7C ) and the associated value ( 0x06 ) to configure the serial enabled backpack for a 20x4 Character LCD.

  • ——————– Tech Support Tips/Troubleshooting/Common Issues ——————–

    Wire Management Tips

    Below are some links for managing the wires in your project by braiding them together: