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 Friday, I work on reducing the final PCB from 16×16 to 14×14. I have discovered two new things: to delete some route, you can use the tool “add partially selected nets”. You will gain some time until you realise that you delete all the GND and VCC nets… By chance, after spending one-hour routing again theses nets, thinking that you would have gained more time by going back in your git, you can use the command fanout that will route again these nets easily. So, the PCB is almost finished, I just need to adjust the board outline and we can concentrate on the code and the test PCB that may arrive one day.… 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
On Monday, I began to have a look at a 16×16 device scheme. For this, I took the 4×4 scheme, I copied it 16 times, and I added two multiplexers. One that will multiplex the SCL signal to the multiplex that controls the Hall effect sensor, and one other that will multiplex the multiplexer that controls the H-bridge drivers. Then, I had some questions.
Should I keep a pull-up or a pull-down between two multiplexers or not? My answers for this moment is to keep a pull-up in order to avoid a clock signal on SCL if there is some latch between the two multiplexers.… Read more