Voltlog #287 – Switching From Eagle To Kicad

Welcome to a new Voltlog, today I’m gonna talk a bit about my process of switching from EagleCad to Kicad. So i’ve been an EagleCAD user for years, I’ve practically learned how to do pcb layout in eagle cad so there is that emotional attachment to a piece of software because it’s what I used while developing this skill. And to be honest there wasn’t any better alternative years ago, Eagle was the first decent piece of cad software to offer a freeware license and it quickly became popular for hobbyists. It didn’t have all the bells and whistles of the expensive software like Altium or Candece but it did the job while being user friendly.

Since it quickly became popular for makers and hobbyists it also meant there was an abundance of support on the forums as well as many user generated scripts and libraries freely available. It was similar to the popularity Arduino got but it was never open source and if you needed some extra features like 4 layer layout or pcb sizes larger than 8x10cm you needed to pay for a license.

Voltlog #230 – Guidelines For Board Level Temperature Sensor Layout & Placement

Welcome to a new Voltlog, today I’m gonna show you some techniques that you can use when doing temperature measurements. Typically you will want to measure either the ambient temperature or the system or component temperature. Depending on one of these goals you are going to follow different design rules to achieve that. And to better illustrate the problems, I have these 3 pcbs which have exactly the same electrical circuit but with different layouts on the pcb.

The boards consist of an esp8266 and a digital temperature sensor and you might expect that since all 3 boards are placed so close together, they should all indicate the same temperature but that is not the case as we can see on this graph we are getting 3 different temperatures and only one of them is close to the actual ambient temperature measured with another thermometer, so why is that happening? Well the answer lies in the layout of the PCB and that includes component placement, copper planes and various other elements on the PCB.