Project Johnson Tiny Robot

I am building a Tiny Arduino robot to do a Kickstarter.

Similar projects worth following
This is a Tiny programmable Robot with BLE, distance sensor, microphone, and a led. My goals for it are many:

1. Arduino or C programmed ARM Cortex-M4F platform with lesson plans so you can level-up (think Goku in Dragon Ball-Z) and become a super engineer.

2, An Edutech device capable of word recognition. Combined with the microphone, BLE, and a buzzer, so it will help children with vocabulary and learning.

3. Just a fun thing to have around, with games like capture the flag with 2 or more.

4. Since it talks over wireless to a PC or smartphone, a world of applications open up.

5. I want to add microPython, Javascript, C++ and other languages so developers can use their preference.

The delivered hardware is a robot and a companion board. The companion board has these features:

1.  It charges the robot's battery

2. It enables programming with the Arduino IDE

The companion board also supports full C and C++ programming. For this you need a programmer, like the Adafruit ARM programmer, and the free Segger Studio IDE. When the robot power switch is off, it is in Arduino/UART mode. When the switch is on, it is in ARM mode.

The firmware/software I want to deliver are:

1. Arduino support

    a. Arduino bootloader

    b. Arduino libraries

    c. Install script

    d. Interesting Arduino programs (examples) I haven't decided yet

2. Android applications

     a. RC app for driving robot

     b. Download words and behaviors for word recognition and robot response

     c. App Templates

     d. Other apps I haven't decided yet

3. Firmware Application

    a. drivers and libraries for custom C development

    b. Interesting applications

...and I figure I will not get enough done unless I get help.

  • 1 × Nordic Semiconductor nRF52832 Microcontroller, ARM Cortex-M4F, 32-bit, 512k Flash, 68k SRAM
  • 1 × Segger Studio It is free with full features for Nordic Semi parts, woo hoo!
  • 1 × Segger J-Link Great for learning and programming ARM microcontrollers. Adafruit makes the cheapest one though.
  • 1 × Sparkfun USB to UART Good for getting UART (serial printf's) out of your design. Also, interfaces to Arduino IDE for programming with Arduino.

  • What is wrong with comparator circuit

    Bill Weilera day ago 0 comments

    Looking closer at the TI TL331 datasheet, I see I was fooled into thinking the offset voltage was 2mV. Looking closer it is this funny formula of VDD-1.5V. I think what it means is IN- and IN+ to the comparator, have to differ by more than (my voltage is 3V) 3-1.5=1.5V. Wow, I will never get that across a 1ohm resistor, I would need amps of current, not milliamps. 

    Also, I think I have to deal with something, because I am self-taught PCB designer, my designs don't follow standards close enough. When I post to Stackexchange asking questions, I get dinged pretty hard for not following conventions in my schematics. Should be an easy thing to learn and fix, but it is building the habits that are hard. Also, I have to follow IPC standards. If I don't, I will confuse my suppliers, and spell doom.

    Here is the schematic, the guy who answered said is was totally confusing because I didn't follow standards, and not using a preferred comparator symbol threw him.

    Here is a link to Stackexchange question:

    Here is the schematic:

    Doom .... doom....dooooom!

  • Video of companion board showing features

    Bill Weilera day ago 0 comments

    Here is a short video of companion board for Project Johnson Tiny Robot Open Hardware Contest.

  • Think I know whats wrong with UART/J-Link switch circuit

    Bill Weiler2 days ago 0 comments

    I think the comparator is not going to switch without much higher offset voltage. I simulated it in LTSpice (free download, but only has Linear Semiconductor parts in it). The mistake is not fatal, I put in a manual override it case it failed. It's a good example of how it is a royal pain to check every little thing, but it can bite later. 

  • Super hightech variable load test appliance

    Bill Weiler2 days ago 0 comments

    I went to the craft store and bought a better exacto. I bought some Sculpteo and made these creatures. I will now bake them in my reflow oven and see if it is like using a kiln. This has absolutely nothing to do with anything or even Tiny Robots.

  • More on companion board and other stuff

    Bill Weiler2 days ago 0 comments

    I found a mistake, the Microchip MCP72832 Lipo charger I put in is different in a way I didn't expect. The status pin is open drain. On the MCP72831 I was using before it is tristate. The charging led would not light. I flipped the led around, then I flipped the resistor 90 degrees, then I solder that to 5V. It lit up and charging works fine. Here is a photo of the rework.

    I also noticed the female connector bends back plugging in if I am not careful. I coudl glue it or some redesign. I put a 1k pot on power to simulate a load, and the comparator doesn't trip to UART. Although at 23.5 ohms (3V/23.5=127mA) the UART Tx and Rx leds light up. I had wanted it to switch to UART mode when sourcing current. Have to figure this out.

    For the laser cut wheels, here i what they look like. I sandwich 3 of the cutouts together. They smell like burnt wood all the time.

    Here are the tires (o-rings). I got black (called Buna) and Silicone (red) to which is stickier. Silicone is softer and stickier, but red might look funny. I actually learning somethings about Durometer, 50D is softer than 70D (the hardness measure).

  • Here is the robot and the companion board

    Bill Weiler3 days ago 0 comments

    It kind of took all day and I need a break. But here it is. The companion board has these features:

    • USB to UART
      • UART or Arduino
    • Robot power switch is Off
      • Arduino/UART mode
    • Robot power switch is On
      • J-Link mode (C programming)
    • Battery charging when USB plugged in
    • USB 5V present red led
    • UART mode green led, off in J-Link mode
    • UART Tx and Rx led's
    • Charging blue status led

    It uses a FT323RL chip so is Arduino compatible, no dongle needed. Plus UART is nice for C debugging. I tested charging and J-Link, works great. When the new robot boards arrive I'll test UART/Arduino.

  • Sent all the 3D printing to Sculpteo.

    Bill Weiler4 days ago 0 comments

    Just sent this robot body, the motor mount, and solderpaste frames, off to Sculpteo to get them printed. They don't do colors as easy as Shapeways, but Shapeways was saying 28 days for delivery, yikes! Sculpteo is about 60 miles away from me, so really close. I think Shapeways is in NYC. (Shapeways is cheaper though). In this design I put a slot for the buzzer to fit in the top. I really need an open sound path and hopefully resonance with the body for volume.

  • Working on Android Studio

    Bill Weiler6 days ago 0 comments

    1. It's kind of weird, but the Android Studio BLE GATT example won't find Tiny Robot, but the Nordic nRF Connect will. I can try and make the example work, or use the Nordic library (no app source). I don't want to go down a rat hole with either one, but I don't want to start from scratch. Tough choice.

    2. Parts and PCB's for companion board (programmer, UART, charger) show up Thursday. Pretty exciting.

    3. Went to an Edtech meetup tonight and got some good advice on using the robot in schools. Like telling me little kids will stomp on it, or try and pull it apart (heard this from the voice of experience).

    4. I costed out the robot, and it comes to $100 in parts (before labor). Obviously this is no good and it kind of bums me out, even though I kinda knew it wasn't going to be great. I regret not being aggressive on cost from the start. I have many ideas for getting the cost down though.

    5. I gave the Shenzhen motor company a good review on Alibaba. 

  • Bought Android Phone to use as robot client (or server)

    Bill Weiler6 days ago 0 comments

    Got a Moto E4 Android cellphone at Walmart to use as Bluetooth client for robot. Now I will write some apps.

  • Latest in Fusion 360, man this software is crazy.

    Bill Weiler03/13/2018 at 04:16 0 comments

View all 13 project logs

  • 1
    For soldering headers flat to a board (not through holes), use solderpaste first. It is much easier than trying to flow in solder wire.

    This technique works well to solder quickly with a soldering iron. It you put down solderpaste on all the pads (leaded parts, like SSOP, TQFP, SOT23, passives), soldering with an iron is just a touch. One trick is press down the component (like the SOT23 part) with tweezers while you touch the pin/pad, otherwise it will move and "freeze" in the wrong spot when the solder cools. 

View all instructions

Enjoy this project?



Bill Weiler wrote 03/09/2018 at 06:19 point

I am using motors I got off eBay. They are sketchy.

  Are you sure? yes | no

Bill Weiler wrote 03/09/2018 at 06:18 point

Here is a new video with the robot moving around:

  Are you sure? yes | no

Matthias Kesenheimer wrote 03/08/2018 at 09:19 point

Nice project! What are the motors you are using?

  Are you sure? yes | no

Bill Weiler wrote 03/08/2018 at 06:33 point

Here is a video:

  Are you sure? yes | no

Bill Weiler wrote 03/07/2018 at 08:42 point

I almost had a video and then poof, one of the motors stopped working and it just spun in place. I am building another one and will have a video soon. I really want to make a lot of videos too.

  Are you sure? yes | no

Mike Szczys wrote 03/07/2018 at 21:37 point

Working on a tiny scale like this makes it so much harder. But that challenge also makes it addictive.

  Are you sure? yes | no

Mike Szczys wrote 03/05/2018 at 23:13 point

Impressive! I'd love to hear more of the back story on this one. I read through some of your G+ and got a kick out of the fried battery/reassembly woes. Do you have some footage of this little guy zipping around the workbench?

  Are you sure? yes | no

Similar Projects

Does this project spark your interest?

Become a member to follow this project and never miss any updates