In the last article about the Bytes Counter, we spoke about some mistakes in the PCB and some possibilities for improvement on the board. In this article, we will explain what we implement in the new (and final) rev 1 and our final impressions with our new partner PCBWAY.
Before starting writing the article, I must say to you that our version is already in Github, so you can access the project. Our first effort was to solve the previous mistakes, which can be summarized in the inability to burn the PIC when the PCB was assembled and the bad choice of the programming port. For the former mistake, we add two diodes (D1 and D2) which will prevent our RF filter from the buttons to interact with the programming port:
About the programming port, we have chosen to use the six wire (and port) from the guys Tag-Connect, which allow us to use a very small footprint, and attach the Pickit to the board during the software developing process:
Other improvements have been addressed as well: All the SMD components are now installed in the top layer, so a simple and faster assembly process can be done with only one Stencil. A new package (TSSOP vs the previous SOIC) for the PIC18lf14k50 has been selected, resulting in a smaller size of the chip. Finally, some final improvements to the holes and pads of the Buzzer and the battery holder have been made (Bigger pads to make those components easier to solder). After applying the solder paster with the Stencil:
After Soldering all the SMD:
The final result can be seen in the next animated GIF:
If we compare side by side, you can also see we change the buttons (to save money on extra parts like the red-green plastics covers) here you can also notice the difference in the solder points on the battery holder (In the new version, they are better):
To end the article, we need to say that changing the PCB manufacturer was also a big improvement since PCBWAY has an improved resolution and generally better quality on the boards. We can focus on the Open HW logo to see the difference:
We hope our relationship with PCBWAY grows stronger so we can collaborate on future projects. Should you need a manufacturer for your projects or business, we strongly recommend having a look at their specs ;).
Let's summarize the changelog:
- Added D1 and D2 to protect the programming port from the RC filter.
- Added a new programming port.
- Enlarged Buzzer and Battery holder pads for better soldering.
- Changed buttons (No footprint change).
- New package in the PIC (TSSOP).
- Move all the components to the Top Layer
- Changed PCB manufacturer.
With all being said, we thank you to read the entire article, and see you around next time :).