ATTiny85 PWM Solar Charge Controller

After receiving Julian’s comment on my first Arduino solar charge controller Youtube video I’ve been thinking of ways to reduce the power consumption, but after a fair bit of reading (and a bit of guessing) I’ve been able to come up with a working prototype. In the video below I look at the code, how to program ATTinys and the trade offs that come with reducing power consumption.

Continue Reading →

Maplin 3D Xmas Tree Build – Fail

I attempted to build a fairly simple electronics kit to decorate the solar shed for Christmas. It’s a simple Astable Multivibrator based circuit which I couldn’t manage to get working as it should. Never fear – add a microcontroller and we’ll get those leds to flash! The code for this project is further down the page:

Continue Reading →

Arduino PWM Solar Charge Controller

After building the Arduino based solar charge controller designed bu Julian Ilett of and laid out by the person behind I thought I’d like to look again at this project.

I’d had comments from people nervous about the soldering – which I too struggled with.  So many components in such a small space made it tricky.  I wondered if I could redesign the circuit board to make it a little easier.  I also wondered if I could reduce the number of components used in the design.

I came up with this version:

arduino pwm charge controller v2 veroboard v3
Continue Reading →

Arduino Voltmeter Clock

As soon as a saw other peoples versions of this clock I knew I wanted to make my own. Using a Arduino Pro Mini (clone) a DS1307 RTC module and three 5 volt  voltmeters I was able to complete the following project in an afternoon.

I now just need to build it into a suitable enclosure.

Continue Reading →

Automatic Grid Tie Switch Verision 3.0!

The latest version of my Arduino based automatic grid tie switch is now finished. This improved version includes a new screen which displays more information and now uses an Arduino Nano (clone). Further more I’ve created my own voltage divider to increase the voltmeter resolution. Continue Reading →

Automatic Solar Grid Tie Switch v2.0

I’ve been working on a new version of my automatic grid tie switch.  If you haven’t seen my previous post or video it’s a device which will switch my sheds solar panels from the battery charge controller to a micro grid tie converter depending on the battery voltage.  The idea is I want my solar panels to deliver everything they’ve got for as long as they can each day. Continue Reading →

Automatic Solar Grid Tie Switch v1.1

My solar shed now generates more power than I can regularly use.  I wanted a way to use that excess energy, but ensure my battery was kept fully charged.

I’ve recently bought a couple of Arduinos to have a play with.  They fit this purpose perfectly.  They can run from the battery, but use very little power.  Using a voltage sensor (which is a simple, pre-built voltage divider) and a relay board, I can easily change the relay based on the voltage input.

This is my first project, so please be kind on the code.  I’m still learning!

Continue Reading →