avatar

Alex the Giant

Member Since: March 1, 2016

Country: United States

Profile

Role

Electrical Engineer

Programming Languages

  • Python

  • C/C++

  • HTML

  • Javascript

  • CSS

Universities

University At Buffalo 2008-2013

Interests

  • Fixing things until they're broken

  • High voltage

  • Tinkering

Websites

wendeblog.com

In this week's Enginursday, we'll explore how to use both cores of the ESP32, and why you might want to.

Continue reading

Let's talk about a PCB design error and troubleshooting the root cause.

Continue reading

This week I'm getting back to my OLED clock, and discussing the changes I've made.

Continue reading

Using a ESP32 Thing and a WiFi camera to create a robot that you control from your browser.

Continue reading

Sometimes troubleshooting requires you to think both literally and figuratively "outside the box."

Continue reading

This week Alex designs an OLED clock using the ESP32 Thing.

Continue reading

In this week's Enginursday, Alex meets with a local Speech-Language Pathologist to talk about how makers can help make devices for people with special needs

Continue reading

In this Enginursday, we'll explore some of the problems that can creep up when connecting I2C devices

Continue reading

Setting up a sensor to text you if your basement is in danger of flooding

Continue reading

Create your very own levitating light with just a handful of parts.

Continue reading

A new twist to the classic party game, Beer Pong!

Continue reading

XBee3 Thing Plus Hookup Guide

August 22, 2019

Get started with SparkFun's XBee3 Thing Plus - both the u.FL as well as the PCB antenna versions.

LiPo Charger Plus Hookup Guide

May 30, 2019

This tutorial shows you how to hook up and use the SparkFun LiPo Charger Plus board.

Buck-Boost Hookup Guide

May 10, 2019

This tutorial shows you how to hook up and use the SparkFun Buck-Boost board.

Using Home Assistant to Expand Your Home Automations

May 9, 2019

An introduction to Home Assistant, an open source home automation hub.

ESP32 Thing Plus Hookup Guide

March 7, 2019

Hookup guide for the ESP32 Thing Plus using the ESP32 WROOM's WiFi/Bluetooth system-on-chip in Arduino.

AST-CAN485 I/O Shield (24V) Hookup Guide

February 14, 2019

The AST-CAN485 I/O Shield is an Arduino shield that will allow the user to interface the AST-CAN485 Dev Board with 24V inputs and outputs, which expands its usefulness into industrial systems.

RedBoard Turbo Hookup Guide

January 24, 2019

An introduction to the RedBoard Turbo. Level up your Arduino-skills with the powerful SAMD21 ARM Cortex M0+ processor!

Introduction to MQTT

November 7, 2018

An introduction to MQTT, one of the main communication protocols used with the Internet of Things (IoT).

I2S Audio Breakout Hookup Guide

September 6, 2018

Hookup guide for the MAX98357A I2S audio breakout board.

Qwiic Differential I2C Bus Extender (PCA9615) Hookup Guide

May 31, 2018

Learn how to extend the range of your I2C communication bus with the Qwiic differential I2C bus extender (PCA9615 ) breakout board.

WiFi Controlled Robot

May 2, 2018

This tutorial will show you how to make a robot that streams a webcam to a custom website that can be remotely controlled.

Noisy Cricket Stereo Amplifier - 1.5W Hookup Guide

April 26, 2018

A hookup guide for the Noisy Cricket Stereo Amplifier - 1.5W.

Adjustable LiPo Charger Hookup Guide

September 28, 2017

The SparkFun Adjustable LiPo Charger is a single-cell lithium polymer (LiPo) and lithium ion battery charger. Because it’s adjustable, this charger will be able to safely charge all of our singe-cell batteries.

ESP32 Thing Power Control Shield Hookup Guide

June 9, 2017

This tutorial shows you how to get started with the ESP32 Thing Power Control Shield.

Roshamglo Hookup Guide

March 13, 2017

This tutorial provides everything you need to know to get started with the Roshamglo badge.

TMP102 Digital Temperature Sensor Hookup Guide

February 2, 2017

How to connect and use the SparkFun Digital Temperature Sensor Breakout - TMP102 with an Arduino.

Wireless Joystick Hookup Guide

January 5, 2017

A hookup guide for the SparkFun Wireless Joystick Kit.

Mini GPS Shield Hookup Guide

December 15, 2016

A hookup guide for the SparkFun Mini GPS Shield.

Reducing Arduino Power Consumption

November 10, 2016

A tutorial about different ways to reduce the current draw for your next Arduino project the easy way.

9DoF Sensor Stick Hookup Guide

August 25, 2016

How to connect and use the SparkFun 9 Degrees of Freedom Sensor Stick with an Arduino

Load Cell Amplifier HX711 Breakout Hookup Guide

July 22, 2016

A hookup guide for the HX711 load cell amplifier breakout board
  • If you're using an LM358 (pinout here), like used in the schematic, the input pins are 2 and 3 and the output pin is 1. so you should connect the positive end of the multimeter to pin 1 not 6. pin 6 is the inverting input of the second op-amp.

  • I think the inductor might be wired backwards. The way the circuit works, is when the magnet is too far away, the op-amp's output should go high (12V) to allow current to flow through the inductor and generate a magnetic field to pull it up closer to the sensor. When it's gets too close, the op-amp's output should go low (0V) and let gravity pull it farther away from the sensor.

    The first tip I would give is to disconnect the inductor from the circuit, and make sure the circuit is working correctly by measuring the output voltage of the op-amp with a multimeter. Without a magnet near the sensor, make sure the output voltage of the op-amp is reading close to 12V. If it's reading 0V, you should be able to adjust the potentiometer until it does. Next bring the magnet up to sensor and see if the op-amp's output voltage changes to 0V. If it doesn't change you might need to flip the magnet over so the other magnetic pole is facing the sensor, or adjust the potentiometer a bit more.

    Once you see the output change, you'll want to adjust the potentiometer until the op-amp starts to switch between high and low when the magnet is around 2cm (3/4in) from the sensor. Once you have that dialed in make sure you keep track of which side of the magnet is facing the sensor. When you connect the inductor again, you should feel the magnet being attracted to the inductor and vibrate a little as you bring that top side of the levitation distance you set earlier. If it feels like the two magnetic field are repelling each other, or the side of the magnet that was facing the sensor during the testing wants to flip over to bottom, the inductor is most likely wired backwards. Once you swap the wires it should fix it.

    Once you can feel it trying to levitate, that's when you've reached my point of frustration. It takes a bunch of patience to keep it in that sweet spot as you slowly let go and it levitates on it's own.

  • The red lead is the signal, the black lead is ground, which should be connected to the rest of your ground signals. The signal coming out of the function generator should be 5V peak-to-peak, with a 2.5V offset. So the high voltage should be 5V and the low signal should be at 0V. The function generator doesn't output very much current. the mosfet connected to the function generator is switching the current from the power supply on and off at the same rate as the frequency from the function generator. So the current you're monitoring is from the 12V power supply. Current measurement can be done by the power supply if it has the capability like this one or you can put a multimeter in series between the power supply and the circuit as shown in this guide.

    All of the 12V power can be supplied by the same power supply, and all of the 5V power can be connected by the same 5V supply.

    The hall effect sensor should be attached at the bottom of the levitation coil in the center so that it can detect the distance of the magnet from the coil. I used electrical tape to hold it place, with the flat side of the sensor facing the coil.

  • I made this a couple years ago, so my memory is a bit faded, but I just manually swept through the frequencies and kept an eye on the power supply's current draw. You'll know you're getting close to resonance as the current draw starts to increase, and as you pass resonance your current will decline.

    The note about C1 being close to IC1 is just for best practice. The capacitor is to filter out any noise on the power supply. The longer the wire is between the decoupling capacitor and the IC you're trying to filter the noise from, there will be more parasitic inductance which can introduce noise back into the supply rail. If it's on a breadboard, you just want the capacitor closer to the op-amp than to the power input connections.

    I'm not sure what you mean by procedure for connecting the power supply, but if you're using a single 12V supply, you can connect a 5V regulator to drop the voltage down from 12V to 5V to create the second power rail, or if using two power supplies, just connect 12V from one supply to the 12V rail, and 5V from the other supply to the 5V rail. With either solution, make sure you tie both grounds together.

    The 5V rail uses very little current (probably a couple mA at most), the 12V supply needs to be pretty beefy. I think the supply I used was rated for 5A, but I levitator probably uses around 1A, and the wireless power transfer uses around 2A.

  • The MCP73833 has a input voltage range of 3.75-6V, so no it does not support PD. There are 5.1k pull down resistors on the CC pins of the type-C connector which set the maximum amount of current to I believe 3A at 5V.

  • The current rating is listed because it depends on a few factors. The board can handle up to 2A of current. The hookup guide provides a few graphs for how much current you can expect based on the input and output voltage, and if a heatsink is used.

    https://cdn.sparkfun.com/assets/learn_tutorials/8/9/5/Maximum_Output_Current_Graphs.png

  • I just measured this earlier this week when I created the Home Assistant tutorial. I was measuring around 5mA in deep sleep.

  • It could be a handful of things, and without seeing the setup it's hard to say. It might be your power supply can handle the levitation or the wireless power transfer, but not both. It could also be that the hall effect sensor is being effected by the wireless power transfer transmitter.

    One of the issues with my design is by having just a single hall effect sensor is the sensor detects the magnetic field of not just the magnets, but levitation inductor's as well. Shahriar over at The Signal Path, did and experiment a few years ago using two sensors: https://www.youtube.com/watch?v=LaGv2FHS5zg

    Hope that helped a little. Good luck!

  • The WiFi Shield uses the ESP8266, which can be configured to be a WiFi host (access point), station (which connects to your router), or both.

  • The answers are in the datasheet. For the baud rate, you can use tables 17-9 to 17-12 (pages 200-203). The smaller the error, the better. It would require some testing to see how large of an error your system can tolerate, but at 1.0MHz, 9600 baud would probably work fine.

    The ADC and BOD are set by different registers, so you can power down the ADC without affecting the BOD. The BOD registers on the 328p are configured in the extended fuse byte (table 25-6, page 296). The ADC is in section 21 (page 250), but the ADC Enable is bit 7 of the ADC control and status register A (21.9.2 or page 263).

No public wish lists :(