Voltlog #254 – Epaper Display Pixel vs Segment Type

Welcome to a new voltlog, today we’ll have a little chat on epaper displays. You probably saw this post I made to my youtube community page a few days ago, it was about my epaper thermometer which suddenly showed the low battery sign and stopped working. I’ve only had this running for 1 month, when I received it, the battery was not connected so I thought it must have been an old battery or a bad one.

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.

Voltlog #218 – Shower thermometer teardown after 10 months of usage

Welcome to a new voltlog, today we’re going to be doing a bit of a destructive teardown on this shower thermometer. You might remember this from 10 months ago in voltlog #172, I got it 10 months ago and ever since it’s been running in my shower and I’m interested in seeing how this looks on the inside after 10 months of usage.

After about 2-3 months of usage I’ve noticed I was getting different temperature readings for the water that I was previously considering warm enough but at that time I figured it was because of the change from summer to winter and I blamed it on the ambient temperature. However I now checked with a thermocouple and the result was pretty bad, the shower thermometer is way out.