• RIP Scooter

    Kyle Isom • 07/23/2019 at 19:09 • 0 comments

    Given the pain with dealing with the superglued sensors and power distribution problems, I'm scrapping this project. I'll build something else on a similar chassis and repurpose the controllers.

    Lessons learned:

    • Supergluing sensors worked well - while they worked. When things went wrong, it made it extremely difficult to fix.
    • Power distribution is the main problem: splitting power to Vmax, 3V3, and 5V.
    • The sensors are really sensitive to voltage.

  • On dying HC-SR04s

    Kyle Isom • 07/22/2019 at 18:17 • 0 comments

    So it looks like these are *really* sensitive to voltage: anything over 5V causes them to die.

    Scooter has a 6V power supply, which is the likely culprit for this.

    It's a problem I've had with other things, so I've started designing a power distribution board based on LM-series voltage regulators; I want to be able to support much voltages than 6V, for example 6-AA packs (9V).

  • Pop goes the sonar

    Kyle Isom • 07/14/2019 at 03:12 • 0 comments

    So, I dug up two more HC-SR04’s and tried them on the robot... they started working, and then died. I’m guessing it’s kickback or something from the motors. I’ll maybe need to build a distribution board to take care of this or set up a separate rail.

    Also need to buy more sensors... good thing they’re cheap.

  • Bad sensor! No cookie!

    Kyle Isom • 07/13/2019 at 23:04 • 0 comments

    Well, it looks like I’ve got a pair of bad sensors. I verified it against a test sketch, and so that’s that. It’ll be a bit of pain to replace them because they’re superglued on, but I’ll figure something out.

  • Sensor woes

    Kyle Isom • 07/13/2019 at 19:53 • 0 comments

    I've been getting sensor output like

    C: -1.00
L: -1.00
R: 120.38
C: -1.00
L: -1.00
R: 122.97

    (C is the centre sensor, L is the left sensor, and R is the right sensor).

    I wonder if it's bad sensors or what.

    Also, had to vendor the SparkFun SCMD library due to an I2C init issue - the upstream tries to start in slave mode.

  • Kicking this off

    Kyle Isom • 07/13/2019 at 18:41 • 0 comments

    I have another project that's a more heavyweight robot, so I decided to build a lightweight one to experiment with some things.

    I took a cheap 2WD chassis I found online, superglued some HC-SR04's I had lying around onto it, and somehow got a controller and motor controller hooked up. I wanted to use some of my Adafruit feathers, but my boards seem to be misbehaving so I just grabbed the Turbo I had lying around to use.

    All of my boards have this weird thing where they only take power via USB or a LiPo battery pack JST connector, so I guess now my robot has two sets of batteries: one connected to the controller, the other supplying 5V to everything else.

    It sort of works. More on that later.