Monthly Archives: July 2016

we’re on tonight…

… and continuing our look at the Arduino SD card writer, so we can build a stand-alone temperature and RH logger and then think about how cheap we can make the build.  I’ve been very busy trying to paint decking while the weather been’s OK for it, but I will try the “Hello World” equivalent at home this afternoon so that I know whether we’re stuck on the wiring diagram for it or not, just to make sure we’re working with the right protocol, since the actual device we have is a bit underdocumented!  As before, if you have a standard Arduino, bring it – saves us disconnecting the bike wheel.   I’ll also see if I can source the right size socket so that we can attach it to a Jeenode, where the right pins aren’t in one of the four main ports.

19:30, CEMC Methodist, in the basement…

this week, a practical construction

It’s another session tomorrow night (Tuesday, 7:30, City of Edinburgh Methodist Church, 25 Nicolson Square), and last time we professed a desire to learn a bit more of the technical detail behind using an Arduino.  So we’re going to try something we haven’t done before – making an Arduino, SD card reader, and battery into a simple stand-in for a temperature and relative humidity data logger.  No fancy user interface, just a reading of the interface standards between the two devices and quick cannibalization of our other code to loop through taking readings and storing them on the card, sleeping when not in use.   We can use

http://garagelab.com/profiles/blogs/tutorial-how-to-use-sd-card-with-arduino

as a guide, although I must check the two SD card readers we have to make sure they conform to the same standards first, because it’s been a while since I looked!

As well as an Arduino Uno, we have an Adafruit Trinket that’s been taking no further than a “blink the LED test”.  I like the Trinket in theory, because it’s small, cheap, and more than capable of many of the things we do – Arduinos and Pis are pretty powerful compared to our simple needs.  So that can be the stretch goal, in case the rest turns out to be fast and easy (which it never does).  I’ll look out the equipment, and my notes about how things work, but I’ll resist the temptation to have a go.  See you then!