On Thursday and Friday, I continue to work on the H-bridge code for the test PCB and finally find a way to implement some timers that should stop the current in the coil.
I also have to go to Télécom to cut another box for testing so that we can even work with the closing of our school. However, we do not have the cable and a battery, so even if our code may work, we cannot make our tests. We hope we could take it at school this week.
Now, I will merge my code with Ilan and Zennedine and I will try to implement a watchdog too that will halt the coil even in debug mode.
On Monday, I spend some times cleaning the PCB, by removing some resistor blocks and capacitors. We cannot take them out easily, so I have to clear them from the scheme one by one. I also move some multiplexers since they were very close to the route border. Now, we have a clean PCB but I need to clean a little the scheme.
I also continue to cut the oak plank for the final device, but I had some problems because of one of the planks which bends during the cutting. Two times. So we need to ship a new one.… Read more
On Thursday, I launched the cutting of three planks with the laser cutter. We finally have to change the size of the box. With the coronavirus, we cannot ask for a 510x510mm PCB, so we choose to make a 450x450mm PCB and a 14×14 box.
I also ask for many estimates for cutting a Plexiglas plank and we should finally cut in the same way this plank since the price will quadruple.
Finally, I change the upper part of our 4×4 box too.
Still waiting for our PCB, I found a lot of little things to do to use my time. Adding some art around our hole, a temporary code for the hall effect sensor, that I cannot know yet if there are bugs or not in it. For this, I take some time at naming the pins in STM32CubeMX because it will be easier then.
I also add a LED for the big PCB, since it will be useful when coding (we forgot to put one in the previous PCB).… Read more
While waiting for the test PCB, I have to find something to do. Our laser cutter is only 30cm large for 610cm long, so I find a way to cut our wooden plank it in three ways. I hope that there will be no need to add something, but if the plank bend, we will have to put some wedge in the middle of the plastic plank.
I also have to unbend the wood. We ship a 3m plank that came wound, so I make something like this
I also cut a plastic plank for our test box
And made a better scheme with CorelDraw for those who want to make the same device
At last, I take a look at Ilan code for the beginning of a thread that will check the state of all the box.
On Thursday, I went to Telecom for the first time of the week. I took advantage of this journey to print the prototype of our box for the test PCB. But I lack plastic plank for the middle part (in green in other photos), so we need to wait for a week to have it. However, we will have it on time because we won’t have the PCB before.
In the afternoon, I began the final PCB. We found before a component for charging the battery on a USB cable (the LTC4088), that I put in the schemes.
After some hours on it, I finally find how to import a DXF file of our PCB.… Read more
Last time, I made a prototype of a box, but there was a problem with the size of the holes for the marbles. They were bigger than the marbles, and they would fall if we put the box vertically. I tried to put the coils and the marbles at a lower level and to reduce the size of the holes. But with this, we have too much friction, and we cannot flip the marbles easily.
The person in charge of the fablab offers to make a printed support for the marbles in order to reduce friction.… Read more