Electronics

Single Port BMS MOSFETs Explained

Tags: Electronics, Solar

I'm writing this post since it seems there seems to be some confusion on why both MOSFETs in a typical single port BMS (Battery Management System) are controlled individually and why/how this works when they're in the same series circuit. It will hopefully also show why just controlling both MOSFETs at the same time to try and accomplish this is not a good idea.

Low Cost 10kW Solar System - One Year Later

Tags: Electronics, Finland, Hardware, Solar

A little over a year ago I published an overview of my off-grid solar system consisting of 10kW of panels and 28kWh LiFePo4 battery. The set-up consisted of all the components to run this solar system - including charge controllers, inverter, BMS, etc. The target goal was a cost of under €10K, which I managed to achieve with some cash to spare. Now that it has been in operation for a year, let's see how well the system held up, any issues that were encountered, and what the current price of the system would be were we to build it again today.

Panel Ground Mount

 

Building an off-grid 10kW solar system with 28kWh LiFePO4 battery, inverter, BMS and charge controllers for under €10K

Tags: Electronics, Finland, Hardware, Solar

Over the past decade or so I've been working on off-grid solar installations big enough to power a house, even during the long, cold (and dark) winter months here in Finland. While November, December and January remain challenging, it can actually be done - and pretty well. The issue in the past has been that doing this was quite expensive. The first implementations I built for this ran in the multiple tens of thousands of Euro and required quite some attention to keep going. These first systems relied on expensive components and difficult to manage and heavy lead-acid batteries. Over the past few years however, the landscape has changed and there are possibilities that I could only dream of even as little as a year ago. The post below details the components, where to get them, requirements, and the cost to get an off-grid solar system with several days of autonomy running for under 10K Euro. 

Solar Power

Slightly Smaller Still...

Tags: ARM, Electronics, Tracker

...and with even more features than before. 

Matchbox 2017

Standard Peripherals Library vs CMSIS vs HAL vs Low Level Library

Tags: ARM, C, Electronics, Embedded, Programming

The STM32 line of microcontrollers offer a bunch of features in a nice package at reasonable cost, something I like. What I don't like as much are the development libraries around it provided by ST. For this reason, most of the time I stick to writing code using the 'Cortex Microcontroller Software Interface Standard' (CMSIS) and the datasheet, and this works nicely but can be slow to develop. While it's still my personal favorite, I recently checked out the other options to see where things are going to do the prep work for some ports of older projects built using the 'Standard Peripherals Library' to newer processors such as the STM32L4.

 

Microcontroller

 

This Is How We Build It

Tags: Cloud, Electronics, Embedded, GPS, Network, Security, Wireless

The problem with the Internet of Things is that few people truly understand what it is really about. A large percentage of people in the group that does understand it tend to discard it as yet another marketing hype such as “the cloud” with very little real substance. Due to all kinds of news reports on security issues, vendor lock-ins and lack of open standards, cost overruns, etc. these people tend to see their opinions confirmed. We at WRD Systems also tend to agree with this group – to a point. The reason we do is that we see the same mistakes being made as countless numbers of times before, including the critical security issues that WRD Systems has highlighted for years. However, we also see the great potential of internet connected devices. Probably not the refrigerators and such, but closer to the origins of the Internet of Things: Machine to Machine, also known as M2M.

paint city titlegraphic

How Small?

Tags: Electronics, Embedded, GPS, Hardware

As some of you may know, we at WRD Systems have been working on our new, next gen, GPS tracker. The goal of this one is to be as small as possible, yet pack as many features as possible out of the box while keeping the cost low. We often get requests asking how small our tracker is. We tried communicating scale in millimeter, or took a picture of the board next to a coin, but they did not seem to convey how small our tracker can really be. To try to improve on this, we present the Matchbox Tracker:

GPS Tracker and Kickstarter

Tags: Electronics, GPS

Ah, this first blog entry of 2013 occurred a little later than I anticipated, but I've been too busy. As you may know by now, our Kickstarter project did not manage to get to the amount of funding we were aiming at. The reasons for this are most likely the lack of media attention (we tried hard though), and perhaps the total amount needed was too high. We also believe the project wasn't crazy enough compared to certain other Kickstarter projects to grab enough attention :-)

Read This!

Back home

Tags: Computer, Electronics

A couple of days ago I returned home from an extensive trip abroad. After getting some needed rest it was time to get back in the home office and start running some updates on my computers. I've got one older Sun Microsystems Ultra-20 workstation which I still use extensively. It's definitely not the fastest machine on the planet, but it gets the work done.

Ultra 20

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