This year we have a module called E-Design which we'll have in both semesters. E-Design is a practical module where we have to design and build an electronically operated gate. We were given a basic PCB with a specific layout, Renesas RL78-G14, LCD screen and number of other components needed to design and build the gate.
Our first task was to build a 5V power supply, it wasn't that hard to build because we were given about 12V from a DC power supply and we had to use a voltage regulated circuit to step the 12V down to 5V. After finishing the power supply we had to connect the RL78 to an external UART and then we connected the RL78 to the LCD screen and display a message on the LCD screen showing the current operating mode, test or normal mode. For know nothing has to happen in normal mode except for switching into test mode and displaying a welcome message .
The whole setup gets connected to a computer for testing via the external UART. Different commands are then sent to the RL78. When in test mode characters received that are not commands must be stored in a buffer. The contents of the buffer has to be displayed when the display command gets received. There are commands for opening and closing the gate, reading the current of the DC geared motor and switching the buzzer on and off. There is also a check status command which receives the status of the gate, opened or closed.
For this module we have 4 demos that we have to do, the 4th demo will be the final product, we have tests that we write on specific parts of the project that we had finished and then finally a report that we have to write. The requirements for passing the module is maintaining an average of 50% in all the different assessments. So that is not good news for me because, believe it or not, I failed the first two demos and the first test. Things aren't looking to good for this module but I believe that I can still pass this module. One of my goals while doing my undergrad is not to repeat a module.
So I failed my first 2 demos not because I could not do the work but because I had some bad luck when I had to go and demo my project, The first time my PCB was faulty and while trying to solve that problem I managed blow up my RL78 board and I had to buy a new one. I was allowed to demo the following week but only for half of the marks.
The second time wasn't very different than the first time, one of my my friends who already went to demo his project told me that the lecturer didn't have a problem with the pin of the gate popping out and that the lecturer didn't subtract any marks for that. I thought that I was also going to get full marks for that section, so I went to demo my gate. Before the demo I told the lecturer that the pin pops out and he told me that it was fine and that the pin on his gate also pops out. Feeling confident, that I was going to get all of my marks, we continued with the demo.
When we tested if the gate opened and closed the pin popped out, still chilled and calm. because the lecturer said it was fine And then all of a sudden the lecturer said that it is going to be a problem and that he has to subtract marks. Now I was stressed because I told him before hand about the pin and he didn't have a problem with it and the same thing happened to my friend and he received all of his marks when his pin popped out. Keep in mind that at this point in time my DC motor could rotate clock - and counter clockwise.
I told the lecturer that I was actually hoping to get all of my marks for that section, it was 5 marks out of the the total that was 12 marks, and he just looked at me and said that that is how it is and if I wanted to I could go and fix it and come back and demo my project again. At this point I was thinking to myself, do you really want to lose 3 out of the 5 marks because a pin popped out... just go fix it and come back... So that is what I did. Keep in mind that there was no need to solder or program anything I just had to take the wire and bend it into a shape so that it would not pop out if the gate closed or opened.
Finishing up the gate I decided to give it a test run... I could not believe my eyes for what I'd seen, all of a sudden my DC motor wasn't rotating in any direction. The DC motor could rotate but not with the control of my RL78 board but by connecting an external power supply to the motor. Now instead of only losing 3 marks for this section I was going to lose 5 marks, and that because of a stupid pin. And that is how I managed to fail my second demo as well, dumb luck!
There are still two more demos left and I have to ace both of them if I want to pass this module, I believe that the tests aren't such a big problem because I can just study for them.
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