Modifying the SparkFun Nano Power Switch

June 24, 2019

I recently obtained a SparkFun Nano Power Timer (PRT-15353) .his is a useful board that will power a device on at a given repeat rate. When to DONE it will power the device off. It will repeat this forever. It  consumes around only 35nA.

One problem with the first version of the board is that the TPL5110 on the board has an option to use a one-shot mode. When the power button is pressed, the unit will power the output for a given time and then power off and wait for the next button press. On the current revision of the board Pin 6 when controls this feature is connected directly to VCC. This puts it in repetition timer mode. To put it into one shor mode this pin needs to be grounded. Elias The Sparkiest at SparkFun has promised (will consider) that this will be changed in the next revision.

However they have over 100 in stock has k so it may take a while. I have figured out how to modify the current boards.

Do this at your own Risk!!!! This procedure is delicate and Tricky! There is a high probablity that you will damage your board and make it unusable. Neither SparkFunnor I are responsible if you break it!!!

OK. Now that we got that out of the way –

  1. You need to disconnect Pin 6 from VCC. Due the way the VCC trace is routed it is not possible to just cut the trace. VERY CAREFULLY un-solder pin 6 from the trace. The pin is very delicate and has a high probability for breaking off. (Ask me how I know :-)). Just bend the pin up a little bit.
  2. As an alternative take an Xacto Knife (new and sharp blade!) an slowly and carefully cut Pin 6 where it turns horizontal to meet the trace. Bend it very gently.
    Cut Pin 6

    DO this at your own Risk. This is a delicate and tricky operation. I AM NOT RESPONSIBLE FOR DAMAGE TO YOUR BOARD!!!


  3. Using an ohmmeter insure that Pin 6 is not connected to VCC. Check Pin 6 to Pin 1. Also check Pin 6 to the leg of the push-button. Do not proceed if you see continuity!!
  4. Finally solder a small piece of wire (I used wire-wrap Wire) connecting Pin 6 to ground. Pin 2 would be  be good for this.


    Add Jumper wire from Pin 2 to Pin 6

  5. Now test it out!


Loveland High School Robotics


Today I visited the Loveland High School Robotics class. The have a First Robotics Team 1977 Power Squids.

I will be working with them as a volunteer mentor.

It was a very enjoyable visit. The had lots of interest in what I have done in the past. I brought Jay 10 my robot as well as my bionic hand. There were very knowledgeable.

I look forward to working with them in the future.

I am Back


Finally I have returned. Last July I retired from Intel in Hillsboro, OR after 2 1/2 years. I moved back to my home in Firestone, CO.

I will be updating the blog more often now that I got organized (Organized. Really? – Linda).

MAVBots  projects:

As I am a volunteer Mentor for the Mead High School MAVBots robotics club I built a couple of bots for them:

  • A Sparkfun RedBot. I upgraded the Line follower sensor and added better bumpers. I also added a pen and lift servo so it can function as a Turtle-bot.


  • MavBot. This is a 310mm x 280mm differential drive robot. It is basically a Redbot on steroids.
  1. it has stepper motors (NEMA 17 – Left over from my 3D printer Project  (see below). I used two  Sparkfun Easy Drivers for control.
  2. Arduino Mega2560 for the brain.
  3. SD card reader.
  4. Line Follower Bar.
  5. LCD Display.
  6. XBee Radio. and
  7. Polulu Micro Maestro to control servos.
  8. Pen Holder with Servo.



My Projects:


Inmov HandInmov Hand


Inmov ForearmInmov Forearm




  • A clone of the TAZ-5 3D printer
    • 300mm x 300mm x300mm print volume
    • DUET Controller and graphics display.
    • Chimera Dual extruder

More to come


Stargate SG-1 Clock


Happy New Year to all!

I still have been very busy at work. 12+ hour days 6-7 days a week. I even had to cut short my Christmas Break and return before the new year. We are bringing up 3 new tablets!

Things quieted down a little this weekend so I had time for a quick Project.

A Stλrgλte SG-1 Clock!

(Yes I know the character is wrong, but it is as close as I can get)

Here is a video:


More details one of these days.


Getting ready for Portland Mini Maker Faire



Sorry for no updates.

I am working on a special project for Intel on the Edison which is taking all my time (even nights and weekends).

I may have an update before I go home for Christmas. I will be working on the motor controller and Quadrature encoder feedback to control motor speed and position.



Getting ready for Portland Mini Maker Faire



It has been a real zoo here getting my bot ready for the Portland Mini Make Faire at OMSI September 13-14. (Presented by Intel). I will be at the Intel booth presenting my Bot as a work in progress. Disclosure: I do work for Intel and they have been very supportive of this project.

My Bot now has a Name: 

JK-BOT (Mark V)

If is the Mark V as it is the 5th incarnation of my Bot.

I am posting a short video status report.  After this weekend I will go into all the details. Here is a link;


Back Again

August 20, 2014 (Updated 8/24/14)


I have been working hard and traveling to Austin, TX and Seoul, South Korea. That took lots of time along with the special projects here at work.

Well I’m back and working on yet another version of my robot.

I was not happy with the base of my previous version.  Due to the steel  I used in construction it was too heavy (26+ lbs), hard to work with, cut and drill, and it was magnetic. Being magnetic means that it work cause my magnetometer (used for  direction sensing) to not work.

The new base will be aluminum. It will have an outer frame of 1″ square tubing. The deck will be 1/16 aluminum sheet I got from Surplus Gizmos. It is a lot lighter and easier to work with.

I am still trying to figure out how to mount the electronics and build the superstructure (I.E. Body). I hope to have the motor mounted and the base electronics in by the end of the weekend. I will post pictures then.

Apdate:Here are the pictures of the new base with the motors mounted. Also I have added ServoCity to the list of link. I was showing the parts I use from them to a co-worker on Saturday and realized ServoCity was not included. OOPS. Since I use their Actobotics Logo - page parts and they really deserve a mention.


The frame is 1″ x 1″ Aluminum tubing. The deck is 5/64″ sheet. Size is 24″ x 24″

Top view of the lower base.

Top view of the lower base.

Bottom view of the lower base

Bottom view of the lower base


Motor Mounts

Motor Mounts


Close-up of motor mount - I used Actobotics clamp style swivel motor mounts.

Close-up of motor mount – I used Actobotics clamp style swivel motor mounts.





More pictures

December 10, 2013

Hi again.

Last night I took some more pictures of the assembled base. I also weighed the base. It came out to 26+ pounds! That’s what 1/8″ steel will do for you! Now on to the pictures –

Views from the front, back and one side.

IMG_20131209_213757_146 IMG_20131209_213718_642 IMG_20131209_213907_580

Side close up.



The back now has a power switch. Also the power bus connectors I got from Adafruit. They make one convenient place to hook the master 12V and Ground.

IMG_20131209_213731_697 IMG_20131209_213739_410

In the front there is a 5″ wide electronics shelf. It contains the Motor Processor (UNO), DRI0018 Motor Driver board, and a 5V power supply. The motor controller will communicate by I2C to whatever Brain is mounted to the upper. The upper portion is designed(?) to be interchangeable. I can put a Telepresence top on, a Manipulator arm, or a Machine gun :-). It is limited only by imagination. Currently I have a Bluetooth module on the motor controller to send commands to for testing.

IMG_20131209_213809_576 IMG_20131209_213835_875 IMG_20131209_213844_013

Well that is all for this year. I will be traveling and visiting the Colorado homestead for all od December.


Happy Holidays

and see you next year!


Back from traveI and MKIII is coming along

December 8, 2013

Hi again.

I have been traveling for the last month  so things we pretty much on hold.

However I got lucky and got some surplus 14″x15″ steel prototype plates.  These suckers are 1/8″ thick. This makes for a good base and frame.  All the holes are tapped for #6-32 screws which makes life nice. They came with additional pieces that I will use to tie two plates together.  There will be an upper and lower plate tied together. This idea is that this will be a self contained base that I can build whatever upper part I feel like and interchange uppers.

This shows the wheel mounted on the plate.  I mounted the wheels inside the the edges for a cleaner look. I had to cut openings for the wheels. In 1/8″ steel it was no easy job.  All the other holes were already in the plate.



(Those in the know may recognize these as VV bases. The were being thrown out so I got a couple.)

Here are the motors mounted on the plate. Notice the screws for belt tension on the outboard side. This may be modified later, but for now it seems to work.



I did a lot of work on Sunday mounting the electronics and power distribution. However I forgot to take pictures. I will take them tonight and post tomorrow.

Halloween Dress Up

October 30-31, 2013

Lots of work on my ‘Bot.

I have re-built the chassie and drive system.  I will also use Bluetooth for the control link. This all will be documented after my trip next week.

However, with Halloween just around the corner, I have added a skin that is a KillBot. If I get things done fast enough –  the head will slowly open, they will take their candy, and the jaws will then slam shut. If I can’t get it done in time, I will just prop the head open.That thing on top is a LED strobe that also plays scary noises. It’s motion/sound activated.

Here are some pictures:

1379243_729049143790948_359187868_n 602104_729049383790924_856426852_n 1378404_729049060457623_104182701_n  1384194_729049350457594_1468407785_n - Copy603043_729049403790922_1118141888_n

Also a look at some of the internals.

I changed my motor drive system/wheels to use  electric scooter wheels. They are from a Razor 200ES from Each one includes a drive cog for a belt built in. It also included a axel and brake which I did not use.  The wheel cog has 72 teeth and the motor cog has 13 teeth. This give a wheel speed of 0.18 of the motor speed. The motor full speed is 600 RPM at 12v. This has proved much more successful.

1380551_729049040457625_1732045886_n 1384194_729049350457594_1468407785_n - Copy

After Halloween I will remove the Skin and Teeth and get back to your regular robot build.