author
28CommentsJoined December 19th, 2015

Tell us about yourself!

Complete Your Profile
  • robertbu commented on CodyBuch's instructable Interrupts Lab3 weeks ago
    Interrupts Lab

    I'm a newbie with respect to Arduino programming, but from my reading, there are couple of changes to your code you should consider:1) I believe any variable that changes value inside an interrupt service routine should be volatile, so randNum, randNum2 and randNum3 should be defined as volatile.2) There are issues with longer interrupt service routines including lost time on the millis() call. A better practice would be to just set a flag in the service routine and then call Blink() in the loop() function based on the flag. With this structure, only the flag would need to be volatile.

    View Instructable »
  • robertbu completed the lesson LEDs in the class LEDs and Lighting Class2 months ago
  • DIY Solenoid Valve to Servo Valve Conversion

    Creative solution! Thanks for sharing.

    View Instructable »
  • How to Make a 5V Voltmeter With Arduino

    Any thought about over-voltage or polarity protection? Also your readings will be relative to theinput voltage which is not necessarily 5.0v. You can get around thisproblem (with some loss of precision) by using Arduino’s built-in voltagereference

    View Instructable »
  • robertbu commented on martinhui's instructable Easy Wire Wrap Tools5 months ago
    Easy Wire Wrap Tools

    The wrapping guns and bits (as well as hand wrapping tools) are available on ebay, but they are $$$. I use empty ink cylinders from ballpoint pens as well as brass tubing to make my wrapping tools.

    View Instructable »
  • robertbu commented on M_Dennis's instructable 9V LED Flashlight5 months ago
    9V LED Flashlight

    Nice, compact idea. You could "double" your light for "free" by using two leds and dropping your resistor to 120 ohms. It would require a slight change in your enclosure design.

    View Instructable »
  • robertbu commented on bcamrl's instructable Nautilus -1 Exploration Mini Submarine 6 months ago
    Nautilus -1 Exploration Mini Submarine

    Cool looking ROV. Iassume you have not yet had it in the water. Some thoughts looking at your design:+ You mention a wireless camera. Wireless signals do not travel well inwater. If your signal is above 1 GHz (asI suspect with the Google Glasses clone), then the signal will only travel afew inches into the water. You may needto either add wire to take the wireless signal to the wireless camera, or gowith a wired camera and bring wires to the surface.+ Based on the photographs, you will need to cut holes in thecowling in front of the propellers to allow water to flow in. + It appears that you are bringing wires in a sheath directlyinto the sub. When bringing in wires ina sheath, precautions must be taken to avoid water getting to the electronics. If the sheath is nicked (a high pr...

    see more »

    Cool looking ROV. Iassume you have not yet had it in the water. Some thoughts looking at your design:+ You mention a wireless camera. Wireless signals do not travel well inwater. If your signal is above 1 GHz (asI suspect with the Google Glasses clone), then the signal will only travel afew inches into the water. You may needto either add wire to take the wireless signal to the wireless camera, or gowith a wired camera and bring wires to the surface.+ Based on the photographs, you will need to cut holes in thecowling in front of the propellers to allow water to flow in. + It appears that you are bringing wires in a sheath directlyinto the sub. When bringing in wires ina sheath, precautions must be taken to avoid water getting to the electronics. If the sheath is nicked (a high probabilityin a rough marine environment), water will travel inside the sheath and intothe electronic boxes. Solutions can befound on the net to avoid this problem.+ You likely will need to make the Cat5 cable buoyancy neutral to avoid it pulling on the sub.+ Inexpensive bilge pump motors usually draw around 3A with theoriginal impeller and likely are designed to handle up to 14.8V (the chargingcurrent of a lead acid battery). Withthe impeller replaced by a propeller the current draw of the bilge motors jumpsto 6A or more, and LiPO 4S batteries will be 16.8V when fully charged. Not sure if any of this will impact you.

    Cool looking ROV. Iassume you have not yet had it in the water. Some thoughts looking at your design:+ You mention a wireless camera. Wireless signals do not travel well inwater. If your signal is above 1 GHz (asI suspect with the Google Glasses clone), then the signal will only travel afew inches into the water. You may needto either add wire to take the wireless signal to the wireless camera, or gowith a wired camera and bring wires to the surface.+ Based on the photographs, you will need to cut holes inthe cowling in front of the propellers to allow water to flow in. + It appears that you are bringing wires in a sheathdirectly into the sub. When bringing inwires in a sheath, precautions must be taken to avoid water getting to the electronics. If the sheath is nicked (a high pr...

    see more »

    Cool looking ROV. Iassume you have not yet had it in the water. Some thoughts looking at your design:+ You mention a wireless camera. Wireless signals do not travel well inwater. If your signal is above 1 GHz (asI suspect with the Google Glasses clone), then the signal will only travel afew inches into the water. You may needto either add wire to take the wireless signal to the wireless camera, or gowith a wired camera and bring wires to the surface.+ Based on the photographs, you will need to cut holes inthe cowling in front of the propellers to allow water to flow in. + It appears that you are bringing wires in a sheathdirectly into the sub. When bringing inwires in a sheath, precautions must be taken to avoid water getting to the electronics. If the sheath is nicked (a high probabilityin a rough marine environment), water will travel inside the sheath and intothe electronic boxes. Solutions can befound on the net to avoid this problem.+ You likely will need to make the Cat5 cable neutral buoyancyto avoid it pulling on the sub.+ The bilge pump motors usually draw around 3A with theoriginal impeller and likely are designed to handle up to 14.8V (the chargingcurrent of a lead acid battery). Withthe impeller replaced by a propeller the current draw of the bilge motors jumpsto 6A or more, and LiPO 4S batteries will be 16.8V when fully charged. Not sure if any of this will impact you.

    View Instructable »
  • Arduino - Voltage and Current Measurement ACS712, ADS1015

    I know this is just a breadboard, proof-of-concept Instructable, but does the ADS1015 buy you anything? The arduino analog pins have 10-bit precision, so you can read down to around 0.05V and 0.06A. And you can increase the voltage precision by changing the voltage divider.

    View Instructable »
  • robertbu commented on pankajchauahan's instructable Make Your Own SIMPLE 4x4x4 LED Cube 6 months ago
    Make Your Own SIMPLE 4x4x4 LED Cube

    Your Ohm's law calculation does not take into account the resistance of the LED, nor the voltage drop of your transistors nor the voltage drop associated with the pin transistor. And each layer is only lit 1/5 of the time, so the average current is much smaller than the intermittent current. If your LEDs are bright enough, you are golden. I only wanted to point out that adding a 330 ohm resistor is not a "free" solution to solve the problem of too much current. The LEDs pay a price in terms of brightness.

    View Instructable »
  • robertbu commented on pankajchauahan's instructable Make Your Own SIMPLE 4x4x4 LED Cube 6 months ago
    Make Your Own SIMPLE 4x4x4 LED Cube

    He is only turning on one led per pin at a time, so he is only drawing 20ma per pin. The problem is that there is a 200ma limit on the total current pulled by all pins output pins. If the code lights an entire layer, the board is pulling 400ma..twice the recommended limit. Note that the amount of current that can be pulled from the 5v pin depends on the voltage regulator used on the board and varies between 0.5A and 1.5A. But that is power does not go through the output pins. And from my reading it is more complicated than just a 200ma overall limit. There also appears to be a 150ma limit on certain sets of pins.

    The use of a 330 ohm resistor on each output line does solve the current draw problem, but at the cost of brightness. The result is running an LED at 6ma that typically draws 20ma. And there is further brightness loss due to the multiplexing.

    View Instructable »
  • robertbu commented on pankajchauahan's instructable Make Your Own SIMPLE 4x4x4 LED Cube 7 months ago
    Make Your Own SIMPLE 4x4x4 LED Cube

    I think you are drawing too much current through the Arduino. Assuming you are multiplexing each layer and each led draws 20ma, you are drawing 350ma through the arduino board. The max from any datasheet I've read is 200ma. Or am I missing something about your design?

    View Instructable »
  • Password Manager, Typer, Macro, Payload ... All in ONE!

    This is a very cool project. Building something small enough for a keychain and useful using anArduino can be difficult, and you pulled it off. Some thoughts (partly for you and partly for anyone considering building one of these):+ I agree with your stance on security. In a perfect world, everything would havestrong passwords, but most people use weak passwords they can remember and thesame passwords on many sites. Strongpasswords coupled with your PassType is a dramatically better system. Someone would need to target a personspecifically and in the real world with PassType.+ Your joystick gives you an easy way to enter a fastpassword for entry into the PassType. You have four states and using five ‘digits’, gives you 1K of possiblepasswords. Coupled with increased tim...

    see more »

    This is a very cool project. Building something small enough for a keychain and useful using anArduino can be difficult, and you pulled it off. Some thoughts (partly for you and partly for anyone considering building one of these):+ I agree with your stance on security. In a perfect world, everything would havestrong passwords, but most people use weak passwords they can remember and thesame passwords on many sites. Strongpasswords coupled with your PassType is a dramatically better system. Someone would need to target a personspecifically and in the real world with PassType.+ Your joystick gives you an easy way to enter a fastpassword for entry into the PassType. You have four states and using five ‘digits’, gives you 1K of possiblepasswords. Coupled with increased time between attempts based on number of failed attempts (stored in EEPROM), and a lockout or erasureafter some number attempts, your device would have reasonable, basicsecurity. And muscle memory would make the five ‘digits’ quick and automatic.+ If you were to create a male USB-C to male USB-A adaptorthat plugs into the USB-C port of the Arduino Pro Micro, then you can easilychoose between the two ports based on the computer you are using. Type A can be a real pain on a desktop (unlessthere is a male to female cable around like in your pictures).+ Using INPUT_PULLUP and five pins for your 5-way thumbwould eliminate the need for resistors.+ You could use the EEPROM on the Arduino Pro Micro ratherthan storing the passwords on the 24LC256. It would only support 25% of the passwords that the AT24C256 would, butthat is still more than enough for my password list.+ The AT24C256 comes in module form forthe Arduino. It would be harder to meetthe size profile, but easier to build without etching a board.+ The 24LC256/AT24C256 has three address pins, so up to 8can be used in the same system.+ With a combination of some of the above changes, aPassType could be built with just some wires and solder. No etched board or even prototype board wouldbe needed. The components would be reduced to 1) Micro Pro, 2) OLED display, and 3) thumb joystick.

    View Instructable »
  • robertbu commented on edgary777's instructable Arduino Sonic Meter / Dynamic Display7 months ago
    Arduino Sonic Meter / Dynamic Display

    Your delay(4) occurs when the segments are dark. That is why the display got brighter when you change to delay(1). Try moving the delay() below where you light the segments. Add a second delay() just after you clear the segments. Start with a value of 1 for the first delay and 4 for the second and then adjust from there.

    edgary777 wrote: I'm not exactly an expert with electronics so I'm not sure if I should have used resistors, browsing some forums I read that you probably should, but I didn't and nothing has burned or exploded so far.I too am fairly new to electronics, but I've spent some time learning about and building multiplex displays. Each segment of your red seven segment display will draw it rated current at around 2.0V. You are driving them with 5.0V. What is saving you is that each segment is only on for 1/4 of the time. If you were to continuously display a single segment at 5.0V, it would burn out. You are probably safe since you are pulling "only" a little over twice the current through each lit segment 1/4 of the time, but you would need the datasheet to be sure. Some leds...

    see more »

    edgary777 wrote: I'm not exactly an expert with electronics so I'm not sure if I should have used resistors, browsing some forums I read that you probably should, but I didn't and nothing has burned or exploded so far.I too am fairly new to electronics, but I've spent some time learning about and building multiplex displays. Each segment of your red seven segment display will draw it rated current at around 2.0V. You are driving them with 5.0V. What is saving you is that each segment is only on for 1/4 of the time. If you were to continuously display a single segment at 5.0V, it would burn out. You are probably safe since you are pulling "only" a little over twice the current through each lit segment 1/4 of the time, but you would need the datasheet to be sure. Some leds have a lot of leeway...5x to 10x. Others not so much. From my reading, one way to reduce the impact would be to increase the frequency. The simplest way for this project would be to drop your delay in your code from 4ms to 1ms. Another way would be to introduce blank "frames". That is, you have four frames, where each frame is lit 1/4 of the time. You would insert between these frames times where no segments are displayed. Of course, the segments will dim a bit.Thanks for the instructable.

    View Instructable »
  • robertbu commented on Alaa HR's instructable RC Hover-Craft7 months ago
    RC Hover-Craft

    I cannot figure out how you make turns. Does the back fan rotate, or the back fins rotate, or ???

    View Instructable »
  • Quick and Easy Solderless Electronic Connection

    What a cool idea. Your instructable says use the 26 gage opening of the wire cutter to cut the tubing, but your picture shows 16 gage opening. I think you want 16.

    View Instructable »
  • robertbu commented on Kreat0r's instructable A Best kept secret to Losing weight8 months ago
    A Best kept secret to Losing weight

    Thank you for this Instructable. I ran across it just after Christmas and started 16/8 fasting the first of the year. I'm down 7+ pounds so far. Also I ran across an article on BBC news: 'Fasting diet 'regenerates diabetic pancreas'. It was mice tests using 5 days of restricted diets followed by 25 days of normal feedings. So there is a lot of research yet to be done on intermittent fasting.

    View Instructable »
  • robertbu commented on randofo's instructable Mad Scientist Extension Cord8 months ago
    Mad Scientist Extension Cord

    Looks cool. It would be safest if the side that plugs into the wall is *not* the side that connects to the middle. I believe this is opposite to how you have it wired, but I cannot be sure. That way when the switch is up out of the block, the copper will not be hot.

    View Instructable »
  • Make Your Own Arduino | ArduinoISP| Learn to Burn Boot Loader Into ATmega328P-PU (UPDATE)

    Thanks for the Instructable. I've read elsewhere that instead of wiring the UNO to the new build, you can just swap chips to burn the bootloader and to program the chip. True? On my to-do list is building one of these with a 4 MHz crystal so it can be run on 1.8v.

    View Instructable »
  • robertbu commented on Kandrix's instructable Wooden Fidget Hand Spinner under $19 months ago
    Wooden Fidget Hand Spinner under $1

    I'm not sure what criteria you used for searching on ebay. When I search I find pages like this one:http://www.ebay.com/itm/5-10-Pcs-608RS-Roller-Skates-Ceramic-Ball-Inline-Skate-Bearings-Drift-Plate-TOP-/291970578896?var=&hash=item43facd79d0:m:mi2VrjjWIEdZyvYWdXXGoqwThey are ABEC 9 and ceramic. They are out of china, so you would need to wait a few weeks to get them. They run $2.13 for one or $9.96 for five.

    View Instructable »
  • robertbu commented on Kandrix's instructable Wooden Fidget Hand Spinner under $19 months ago
    Wooden Fidget Hand Spinner under $1

    If you look on ebay or other sites out of china, you can purchase ceramic bearings for around $2.00 each. This video: https://www.youtube.com/watch?v=vLL-T4Z_TNo has a comparison between ceramic and steel bearings, and he goes through his ebay search criteria for his ceramic bearing purchase.

    View Instructable »
  • robertbu commented on bxl4662's instructable Arduino Based Stranger Things Lights1 year ago
    Arduino Based Stranger Things Lights

    Thanks for the instructable. I made one for Halloween using a tri-fold foam display board. That way I can store it and get it out again next year. The lights go through one of several patterns for 5 or 10 seconds then dim and spell out one of a dozen words. I added a flickering lamp (controlled by the same arduino) that dimmed when the words when the words were being spelled out.

    View Instructable »
  • robertbu commented on bxl4662's instructable Arduino Based Stranger Things Lights1 year ago
    Arduino Based Stranger Things Lights

    You are right that you cannot pull the power from the 5v pin, but you can hook it up the opposite way. That is power both the Arduino and the lights from your 10A power supply by connecting it to the 5V pin of the Arduino. You would want to reverse the hookup so the Arduino and the power supply come from the same end of the lights (to avoid voltage drop). And you need to be careful during development to always unplug the USB cable before unplugging your power supply. If you unplug power supply first, the lights will try and pull the power from the USB cable and something will give. Last time I made this mistake I burned out a port on my USB hub. Your two power source solution is simpler, safer, and it avoids soldering.

    View Instructable »
  • Arduino : How to Control Servo Motor With Arduino

    As you say a SG90 should be safe...as long as there is only one and not a lot of other things drawing current. The highest stall current I've seen for the SG90 (at 5v) is 0.75A, and most specs are closer to 0.6A.

    View Instructable »
  • Arduino : How to Control Servo Motor With Arduino

    For testing this servo (MG996R) or for developing code with no load on the servo, this setup will work fine. But under load there is a danger of overloading the voltage regulator on the Arduino. When stalled, the MG996R can draw up to 2.5A. For many Arduino boards, there is a limit of around 800mA drawn from the regulator. If there is any chance of the servo stalling or even being under high-torque, provide an separate power source for the servo.

    View Instructable »
  • Arduino : How to Control Stepper Motor Via Bluetooth (with Smartphone)

    If you are running something like a pro-mini running on 3.3v, there is no issue, but most Arduino boards are 5.0v. I looked at a several HC-0x boards I have here, and they all say, "Level 3.3v. Power:3.6 - 6v." So using 5v to power them, is not an issue. In addition sending 3.3v as a high signal from the HC-0x to the Arduino is also not a problem. The problem is the sending the 5v signal from the Arduino to the HC-0x. Early on I had a problem with *some* boards. The problem was solved by adding a voltage divider...which is just two resistors correctly placed.

    Note, I've had problems with some HC-5 and HC-6 modules wired in the configuration you specify. The issue is a 5v Arduino txd signal being received by the HC-x 3.3v rxd pin. A couple of resistors used as a voltage divider to bring the voltage down to 3.3v fixed the problem for me.

    Note, I've had problems with some HC-5 and HC-6 modules wired in the configuration you specify. The issue is a 5v ARduino txd signal being received by the HC-x 3.3v rxd pin. A couple of resistors used as a voltage divider fixed the problem for me.

    View Instructable »
  • robertbu commented on leomiranda's instructable Variable Bench Power Supply1 year ago
    Variable Bench Power Supply

    See image at this link for the labeling of the potentiometers:http://wiki.beyondlogic.org/index.php?title=WD2002SJ_LTC3780_Synchronous_Buck_Boost_Converter_Ebay_Automatic_lifting_pressure

    See image at this link for the labeling of the potentiometers:http://wiki.beyondlogic.org/index.php?title=WD2002SJ_LTC3780_Synchronous_Buck_Boost_Converter_Ebay_Automatic_lifting_pressure

    View Instructable »