diy on soldernerd

RaspberryPi Robot

Mon, 18 Sep 2017 00:00:00 +0000

It’s been almost two years since I did (or at least started) this project but I never sat down to document it. That’s what I want to do today. As the title says it’s about a little robot based on a RaspberryPi. Like many of its kind it is driven by a pair of stepper motors each driving a wheel directly attached to the respective motor axis. At the back there is another smaller, pivotable wheel to keep the robot in balance.

MPPT Solar Charger Rev C Design

Wed, 22 Feb 2017 00:00:00 +0000

Over the last year or so I’ve designed, built and tested a standalone solar charger. It performed quite well but as with any complex design there were a number of things that needed to be improved. So I eventually reached the point where I decided to design a revised version. And this is what this post is all about.

Ultrasonic Anemometer Part 30: Downsized Hardware

Sun, 05 Feb 2017 00:00:00 +0000

In my last post of this series I’ve looked at different transducers and finally decided on a entirely waterproof 14mm model. The much lower signal level from those kind of transducers makes it necessary to reduce the distance between the transducers in order to still receive a reasonable signal amplitude. So I took my previous lasercut design and reduced it in size so that the distance between the transducers is only 120mm. I went to the local FabLab and and lasered two copies of the downsized design.

MPPT Solar Charger Testing II

Tue, 15 Nov 2016 00:00:00 +0000

It’s time to follow up on the MPPT Solar Charger project. Progress has been slow since I’m currently working full time and doing a master’s degree at the same time. Given that this blog has previously been something close to a 50% job at times things will necessarily slow down a bit. But all the projects, including this one and the ultrasonic anemometer are alive and well and I’m working on them whenever I find some time.

Ultrasonic Anemometer Part 28: New hardware tested

Wed, 07 Sep 2016 00:00:00 +0000

I last time proudly presented the new RevB board and got a lot of feedback from people who want one, too. As mentioned I have all the components here to ship up to 10 kits but I was reluctant to send anything until I had the chance to do some hardware testing. Not much had changed since the last revision but I don’t like taking chances on things like this.

Ultrasonic Anemometer Part 26: Rev B Board ordered

Sat, 20 Aug 2016 00:00:00 +0000

I recently ordered my first PCB at dirtypcbs.com and the result was promising. So there was nothing stopping me from finalizing the Rev B of my standalone Ultrasonic Anemometer and ordering a protopack. I’ve placed the order a few days ago and expect the boards to arrive here in 2 to 3 weeks. This should be good news for all those of you who have been asking for kits and want to contribute to the further developement of this project. I’ll build up one or two boards as soon as they get here and do some testing. If everything works as planned I can order some more components and ship some kits soon after that.

Ultrasonic Anemometer Part 25: I2C Interfacing and more

Thu, 11 Aug 2016 00:00:00 +0000

It’s been a long six weeks since my last post but that doesn’t mean that I haven’t done anything since. Among other things, I wrote some code to get the I2C interface working and hooked the anemometer up to an Arduino Uno with an LCD display attached. Apart from demonstrating the I2C interface this also nice for testing. For the first time I can see what this thing is measuring in real time without hooking it up to a PC over USB.

Ultrasonic Anemometer Part 24: New Microcontroller and Software Controlled Gain

Sun, 26 Jun 2016 00:00:00 +0000

It’s been almost three weeks since my last post and some further progress has been made. I’ve upgraded the microcontroller and can now control the gain of the second amplifier stage in software. But let’s look at the changes in some more detail.

Ultrasonic Anemometer Part 20: Standalone Anemometer Design

Wed, 11 May 2016 00:00:00 +0000

Last time I outlined my reasons to ‘go digital’ by adding a powerful on-board microcontroller and designing a standalone wind meter.

In the weeks that followed that decision I tried to find a suitable microcontroller and to design a prototype. Today I’ll show you the result of that work.

Ultrasonic Anemometer Part 19: Testing the Analog Circuit

Tue, 26 Apr 2016 00:00:00 +0000

In my last post I went through the design of the analog part of the ultrasonic anemometer. Today we will see how the circuit designed last time performs in practice.

Ultrasonic Anemometer Part 18: Analog Signal Processing

Tue, 19 Apr 2016 00:00:00 +0000

Recently, I’ve sucessfully tested the new driver ciruit for my ultrasonic anemometer. It performed even better than I expected and I will be happy to use it pretty much as it is.

Temperature Controlled Fan

Sat, 09 Apr 2016 00:00:00 +0000

I’m currently mainly working on my new anemometer design but once in a while I get distracted. For example when my Keysight E3645A lab power supply was making so much noise that I could hardly concentrate. That’s when the idea of this fan controller was born.

Ultrasonic Anemometer Part 17: Lasercut Mechanical Design

Wed, 06 Apr 2016 00:00:00 +0000

In my last two posts I have gone through my new anemometer circuit both in theory and practice. Click here for an overview over my ultrasonic anemometer project.

Ultrasonic Anemometer Part 16: Testing the new driver circuit

Thu, 31 Mar 2016 00:00:00 +0000

Last time I’ve presented my new design for the ultrasonic anemometer driver circuit. So now it’s time to see how it performs. If you’re new to this project you might want to check out the overview page or at least my last post.

Ultrasonic Anemometer Part 15: A new attempt

Tue, 22 Mar 2016 00:00:00 +0000

It’s been about one and a half years since I started out with my ultrasonic anemometer project. Like others before me I had to notice that this a much more demanding project than it appears to be at first. After countless hours of development and testing I have built this Arduino shield. It worked but the reliability of the measurements was never what I had aimed for. The problem was mainly how to figure out the absolute phase of the received signal. So the measurements were always precise - but sometimes off by a full wavelength. Then I was more or less inactive for most of 2015, mainly due to personal reasons. So the project was kind of stuck but i kept (and keep) getting a lot of encouraging feedback from you folks. I came up with new circuit ideas and decided to pretty much start with an entirely new design and to re-think each and every design choice I had made back then.

PWM Dimmer for RGB LED

Sat, 05 Mar 2016 00:00:00 +0000

Finished RGB dimmer

In my last post I’ve described the design and construction of my LED dimmer project. This project here is similar but a bit more involved. It controls RGB LEDs so it can not only change the brightness but also the color of the light. Instead of a simple pot it used a pair of rotary encoders with push buttons. One controls the brightness, pushing its button turns the light on or off. The other changes the color, pushing its button toggles between color and white.

Arduino MPPT Solar Charger Shield – Software

Fri, 12 Feb 2016 00:00:00 +0000

There have been two previous posts on this project: one on the concept and the hardware and one on hardware testing. You probably want to check them out first if you’re not yet familiar with this project. Or even better: Click here for an overview over this project.

Arduino MPPT Solar Charger Shield - Testing

Wed, 03 Feb 2016 00:00:00 +0000

First tests are being performed on the Solar Charger Shield

In my last post I’ve introduced a proof-of-concept Arduino solar charger shield. I went through the hardware as well as the way it works - or at least is intended to work. It was prominently linked on dangerousprototypes.com as well as some other sites and got quite a bit of publicity as a result. Thank you all for sharing this post.

Arduino MPPT Solar Charger Shield

Thu, 21 Jan 2016 00:00:00 +0000

A friend has approached me regarding his solar project. He wants to install a solar panel together with a battery and an inverter in order to have power at his allotment garden. He had looked at a hobbyist project where an arduino was used to build a MPPT (maximum point of power tracking) charge controller. I took a look at the design, liked a lot of what I saw and decided to build something similar.

Stand-alone Inductance Meter

Tue, 13 Jan 2015 00:00:00 +0000

Some of you may have seen my arduino-based inductance meter in this post: /posts/arduino-based-inductance-meter/. The guys at dangerousprototypes.com picked it up (http://dangerousprototypes.com/2014/12/16/arduino-based-inductance-meter/) and this blog got more visitors than I could ever have imagined. Thanks, dangerousprototypes.

Arduino-based Inductance Meter

Sun, 14 Dec 2014 00:00:00 +0000

Incuctance meter in action. It displays the resonance frequency together with the inductance

I’ve just finished a little Arduino project. It’s a shield for the Arduino Uno that lets you measure inductance. This is a functionality that I found missing in just about any digital multi meter. Yes, there are specialized LCR meters that let you measure inductance but they typically won’t measure voltages or currents. So I had to build my inductance meter myself.

Arduino Ultrasonic Anemometer Part 9: A new hardware

Mon, 24 Nov 2014 00:00:00 +0000

My first wind meter prototype is kind of working. The software will need improvement to make this wind meter into something really useful. But both hardware and software are basically functional and can be built up upon.

Arduino Ultrasonic Anemometer Part 8: More Software

Sat, 22 Nov 2014 00:00:00 +0000

In my last post I talked about how to get the Arduino to output bursts of 40kHz pulses. Today I’ll go through the rest of the software so by the end of this post we’ll have a very rudimentary but working sketch for our ultrasonic wind meter.

Xilinx Prototyping Board

Mon, 10 Nov 2014 00:00:00 +0000

Some time ago I wanted to try out programming CPLDs in VHDL. I was entirely new to both of those topics and I didn’t have a real need for a CPLD at the time. So I built myself a nice little prototyping board for the Xilinx XC9500XL complete with some push buttons, LEDs a 7-segment display and a PIC16F688 used mainly as a clock source.