PCB

LibreServo v2.3 PCB

A few days ago I presented LibreServo version 2.2 and announced that I had one last final change... this time the wait has not been long and I bring the new version of LibreServo, version 2.3.
This version should already be the final hardware version of LibreServo .
The biggest change that LibreServo has had in this latest version with respect to the previous one is the H-bridge. Risky move seeing what it cost me to make it work but I think it will be a remarkable improvement and the missing component to make LibreServo the definitive option.

LibreServo v2.2 PCB

Pre-final version. This was going to be the final version, was going to be, because in the end it is not going to be.

• The oscillator has been changed for a more compact one.
• The position of several components has been slightly reworked
• Ground planes have been generated on the outer layers
• The position of the silk-screen printing has been repositioned with the idea that the vias will be capped and it will be possible to silkscreen on top of them
• The PCB has been narrowed by a few tenths of a millimeter to fit perfectly to the servomotors
• The two PCBs have been joined by using mouse-bites

In general, they are all small changes, but... just before placing the order I went back to review each and every one of the components, and there is one that I have decided to change and it is a very important one that has been in LibreServo from the beginning. In the next article I will unveil the final change 😉

New LibreServo v2.1

A few days ago I received the LibreServo boards I had ordered from JLCPCB. As I told you in the article of changes in LibreServo v2.1, the new version of LibreServo added two extra layers to reach the 6 layers and thus have the offer of JLCPCB and after receiving them and see them ... I only have words of absolute amazement.

The result is magnificent, not only the gold finish looks great in it 😎, the silkscreen itself is much better than when you order plates of four layers or less and the tracks filled with epoxy and covered in copper give an extraordinary result, not only at electrical/routing level and for soldering is a huge improvement, but also allows silkscreen printing on top of vias without any problem, which in LibreServo with the philosophy that has to point all the components to facilitate then when soldering, it comes great.

LibreServo v2.1 PCB

These schematics will not last long because new changes have already been made and will be sent to manufacture in the coming days if all goes well. The order of the next version will coincide with the Chinese vacations, but I hope not to have any problem except some small delay already announced by the manufacturer JLCPCB.

In this LibreServo version, the main PCB, goes from 4 to 6 layers because JLCPCB, as we mentioned in the article of changes in LibreServo v2.1, has made a very aggressive offer in which it is cheaper to manufacture a 6-layer PCB instead of 4, taking into account that in 6 layers you get for free the ENIG finish (in gold) and the vias are filled and covered, in other words, a totally professional finish. It is a really crazy offer.

Despite all this, of course LibreServo will maintain full compatibility with 4 layers and only when generating the gerbers the central layers are removed and the matter is solved.

LibreServo v2 PCB

I had pending for months to upload the schematics to the web. The schematics are exactly the same with which I made the LibreServo v2 PCBs but with the texts corrected in position so they read better.

In previous posts as you can read in the article of the first LibreServo test board and in the conclusions of the second LibreServo test-board, the LibreServo changes were massive in each and every aspect. Virtually every component was overhauled and moved to a two PCB, four-layer design.

Soldering the first LibreServo v2

This little entry is to announce that the new LibreServo has arrived, I was able to solder it without any problem and it is fully working! 🥳

After the tests I did with the test boards v1 and v2 many changes were made to the design of LibreServo. Because of those many changes, LibreServo moves to version 2.

LibreServo sending data via RS485 to Arduino plotter

After several tests, the LibreServo hardware is finally chosen and it's working, even the H-bridge that gave me a lot of problems! In general, all the parts of LibreServo remain as they were, because they were already working correctly, except the parts are discussed in this article.

Hello World in LibreServo PCB test v2

A month ago I was analyzing the results and conclusions obtained with the LibreServo test PCB v1 and trying not to lose momentum this month I have designed, I have ordered new PCBs and I have already assembled the LibreServo test PCB v2! 🥳

It is the first PCB that I have designed with 4 layers for LibreServo and I hope that this will mitigates some issues with the H-bridge that I think comes, in part, from electronic noise. For the rest, it is a PCB with the final components, it is closer to the final design in which I have forced myself to put the components as close as possible to each other to see the real limit between what is designed and what can be easily welded without overcomplicating things, everything holds up on paper but then you have to bring it to reality.

LibreServo test PCB

It has been a long time since my last update, a pandemic in between and many changes. Be that as it may, LibreServo continues moving forward, little by little, but it moves 💪.

During the previous versions of LibreServo I have continually encountered different problems in the design and without knowing exactly how different components were going to behave, in addition, later trying to debug the board being so compact and without extra space to be able to even solder a cable to be able to see the signs, always complicated everything too much.

Hace años me costó bastantes dolores de cabeza tener todas las piezas claras y como sé que el artículo más visitado de LibreServo es Software para programar STM32, voy a intentar realizar un artículo que conglomere todos los pasos necesarios para poner a funcionar desde cero un microcontrolador STM32, tanto a nivel de diseño electrónico, como de programación. Como LibreServo está basado en el microcontrolador STM32f302K8, todo irá referenciado a éste microcontrolador por facilidad, pero los pasos son exportables a todos los microcontrolador más comunes de la familia STM32 ARM Cortex de ST, de hecho, si es tu primer proyecto no sería la mejor opción con la que empezar, más que nada por el encapsulado que trae. El STM32F302C8 sería el gemelo pero en un encapsulado mucho más sencillo de soldar. Pero hay literalmente decenas de microcontroladores según lo que cada uno requiera.

Esquema electrónico mínimo para STM32