I collected two of the three project report drafts on Monday (the other was turned in late, and I haven’t had a chance to pick it up yet). The reports are looking better than the initial proposals—the groups are beginning to flesh out their initially vague ideas with some details (like calculating how much power is needed to heat the block in the PCR machine). They have 3 weeks until their final report is due, so I expect that the drafts will continue to improve. Of course, it is possible that the rate of improvement may be more or less than my expectations (more and their grades go up, less and their grades go down).
On Monday, we tried developing the control algorithm needed for thermal control for the incubator project and the PCR machine. Because of the amounts of power needed, and the lack of electronics sophistication in the class, I recommended using a relay rather than transistor switches. This limits them to on-off control, rather than proportional control or PWM control, but even developing the program for simple on-off control took us most of the hour—the idea of programming and the level of detail needed to communicate the idea to computers is still very new to them.
On Wednesday, I expect to break into groups, and the group tutor and I will visit each group trying to answer questions and help them work out the next steps in their design and try to figure out how to get some prototyping done. Even a cardboard mockup would help them work out some of the problems.