Be prepared for the big one

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.

A little smile for the photo…electric sensor

So, we had to design a small PCB in order to place the photoelectric sensor that allows us to measure the rotation speed (remember, we planned the possibility of using this sensor or a hall effect sensor).

This sensor is a small fork with an emitting infrared diode one one branch and two sensors on the other. When an obstructing object is placed between between the LED and the sensor, it can be detected.

Photoelectric sensor

The PCB will be screwed under the lower mechanical plate. We had an argument to determine if the connector to the mainboard should be on on the same side or the other side of the PCB.… Read more

Catching up on posts

I haven’t posted in a while so I’ll try to catch up with this post.

My main occupation for the last three or four work sessions was to implement the program that takes in input a string, and then displays this string on the outer circle of Litspin.

My first thought was that I wanted to implement it for the simulator, but firstly it was not that interesting to have a simulation for the display of a simple string, and secondly, it would be nice if we could use Litspin to display debugging information.

For the first point, I nevertheless decided to implement it on LitControl and make it possible to display it on the simulator, because I though that it wouldn’t make sense to be able to display 3D models but not simple strings.… Read more

ok, BOMmer.

On this new episode of the Mainboard update, nothing too exciting. Alexis did the final touches on the PCB, made the silkscreen and we should be good to go. Only thing left to do was create the Bill Of Material. I had to fill up a spreadsheet with the components, distributor and number of unit in stock to check whether they would be available when needed.
Some errors were found as well as some components that weren’t distributed anymore but nothing major.

We now can focus on the other PCBs and get them ready as well.

The issue that can prove quite difficult is that due to health and safety concerns with the spread of the corona virus, PCB manufacturing has been halted in China and Europpean manufacturers therefore have massive delays.… Read more

Stuff

We are still waiting for our test PCB, so on Monday I create a HAL file with STM32CubeMX for the test PCB, merge it with Ilan’s code and I will wait that we receive the PCB to check if the merge was ok or not.

Today I’m in Telecom, so I will try to finish the box (I did not have a plastic plank last time) and to begin the box for the final devices.

GDBug and other glitches

Executing our code from flash

Last week Sibille and I moved our bare-metal code for the processor-PCB (which so far was directly inserted in RAM by the GDB debugger) into the Flash memory proper, and wrote code that will execute from Flash to copy everything in RAM and continue execution from there.

However, we soon noticed a strange bug: the GDB debugger now ignored every breakpoint we tried to set in RAM (breakpoints to parts of the code executed in Flash before the copy to RAM still worked fine). After a lengthy debug session, Alexis determine that it‘s a bug from the GDB debugger and not from our code.… Read more

Become the sender !

As I wrote in my previous posts, the ESP, the STM and the server were working together to receive images or animations depending of what the user wants. Now it’s time for the STM to become the sender.

The objective:

We want the devices to be able to received images from the server but we also want to establish a connection between Touchs to send images from one to the other. On top of that at the end we want to have a communication between both devices in both ways. But as you may know chi va piano va sano. So first things firts, we implemented the emitting part for the first device.… Read more

There can only be one SD card in town

On the Aries MCV, the MMC pins of the HPS are already used to control the MMC flash. However, we need an SD card. So, we decided to add a µSD card on the SPI1 interface because SD cards can be controlled in SPI. So, I added the µSD card to the SPI1 interface like this:

&spi1 {
	status = "okay";
	clock-frequency = <100000000>;

	mmc-slot@0 {
		reg = <0>;
		compatible = "mmc-spi-slot";
		spi-max-frequency = <50000000>;
		voltage-ranges = <3300 3300>;
	};
	
};

Before testing on the MCV, we realize tests on the DE1-SoC. Something to notice, we already built the Linux kernel for the DE1-SoC and it booted correctly without the SD card on the SPI interface.… Read more

Live wire

Yesterday evening, the whole groupe work together to test the power transmission through the ball bearings. Those tests are significant to determine if we need to add a 5V-regulator on the main board, and which regulator we choose for the bottom PCB  to account for the tension drop.

Electrical setup

We had ordered the resistors (two 0.5Ohms/25W resistors and one 0.1Ohm, 30W)  described in this article and used them to build the following electrical setup:

The generator supplies 5V because we plan to use a 5V regulator on the bottom PCB and send 5V to the main board through the ball bearings. … Read more

Another success for the Ultimaker

Yesterday the print for the support of the LED PCBs finished, and it was a success:

This was again printed using the Ultimaker 2.

Under it you can also see the support for the processor PCBs, everything fits well:

We also had our school mechanic drill all the necessary holes on the PVC platform, and we will try to make the whole structure turn with our motor today.

I also printed a model which exactly matches the size and shape of the top PCB, and one for the petal PCB, and it fits very well:

As you can see both printed PCB perfectly matches the holes of the structure 🙂

We’ll keep you updated on how well our structures fares at 30 rotations a second !