I'd only managed to get one soldering iron working anywhere near decently. One has completely died and does not heat up at all. The other one refuses to tin despite having the tip well cleaned. I brought one of my soldering irons from home in so that there would be at least two working irons for the session.
Neither of the two Gamers completed today worked completely correctly first time. The red led would blink when the Arduino was loaded with the program from lesson 3 but when a game or animation was loaded - nothing.
On inspection one Gamer had a couple of wobbly solder joints which when re-made fixed the problem. The second took a bit longer to diagnose... until I noticed that the two chips had been inserted in the wrong sockets. We swapped them over and the full set of Gamers was now in operation!
Meanwhile the other pairs were either finishing off their animations (lesson 4) or starting work on controlling an animation using the light dependent resister (LDR) (lesson 5). I'd set my own gamer up running the code and it was good to demonstrate what they were trying to achieve before they started.
I particularly liked the Minecraft Creeper head in this animation:
There were plenty of issues with syntax errors in the code. The kids were often not reading the worksheets carefully and just skimming between the code snippets. Consequently they put lines of code in the wrong place or were getting things the wrong side of brackets. This is all part of the fun/learning process and by the end a couple of the more intuitive programmers were started to get a feel for the Arduino code.
Things to do differently next time?
I should have demonstrated the whole process of monitoring the serial line to discover the range of values from the LDR. The instructions don't make it clear what you're trying to achieve at the start and a couple of pairs got confused about what the code they were writing was trying to achieve.
Check for swapped chips earlier!