They are simply dust, fingerprint and scratch magnet, everything is summarised in the amazing book The Hardware Hacker: Adventures in Making and Breaking Hardware from Andrew ‘bunnie’ Huang

“My world is full of small frustrations like this. For example, most customers perceive plastics with a mirror finish to be of a higher quality than those with a satin finish. There is no functional difference between the two plastics’ structural performance, but making something with a mirror finish takes a lot more effort. The injection-molding tools must be pains-takingly and meticulously polished, and at every step in the factory, workers must wear white gloves. Mountains of plastic are scrapped for hairline defects, and extra films of plastic are placed over mirror surfaces to protect them during shipping. For all that effort, for all that waste, what’s the first thing users do? They put their dirty fingerprints all over the mirror finish. Within a minute of a product coming out of the box, all that effort is undone. Or worse yet, the user leaves the protective film on, resulting in a net worse cosmetic effect than a satin finish. Contrast this to satin-finished plastic. Satin finishes don’t require protective films, are easier for workers and users to handle, last longer, and have much better yields. In the user’s hands, they hide small scratches, fingerprints, and bits of dust. Arguably, the satin finish offers a better long-term customer experience than the mirror finish. But that mirror finish sure does look pretty in photographs and showroom displays!”

Here is a very simple fume extractor fan, to put an halt to apnea soldering.

Made of:

• DC/DC buck boost converter (3€ on ebay)
• USB battery pack 5€
• scrapped fan
• scrapped switch
• scrapped potentiometer
• Hammond prototype case (1€, same as my USB motion sensor)
• nice labels
• double side tape

Enough talk, a picture:

And in action, can suck up to 15cm at medium speed:

This “hack” took me 30min, and costs close to nothing, while some have been down to build a DC/DC converter for this!

Thing to add in the future:

• active carbon filter for better filtering, but usable as is for small jobs: you don’t get fumes in your face anymore.
• USB light for soldering in the dark

My favourite use: in the freezer/fridge, when you forgot to chill beers for an unexpeted party, it takes only 10min to have freezing beer instead of 1h. (remove the carbon filter first…)

Ever wanted to have nice plot (U/I curve, whatever) simply plotted?

I got 2 UNI-T UT61E with USB cable (50€ each)

With sigrok you can easily get data from many device with a single command:

sigrok-cli –driver=uni-t-ut61e:conn=BUS.DEVICE -O analog  –continuous

Where BUS and DEVICE is replaced with the output of lsusb

lsusb
Bus 002 Device 002: ID 8087:8001 Intel Corp.
Bus 003 Device 086: ID 1a86:e008 QinHeng Electronics HID-based serial adapater
Bus 003 Device 087: ID 1a86:e008 QinHeng Electronics HID-based serial adapater

In my case, as I’ve 2 devices, so 2 different commands are used:

sigrok-cli –driver=uni-t-ut61e:conn=3.86 -O analog  –continuous

sigrok-cli –driver=uni-t-ut61e:conn=3.87 -O analog  –continuous

 

But what about logging in the same file the two ouputs simultaneously?

Here comes the magical function: paste and joined pipe:

paste <(sigrok-cli –driver=uni-t-ut61e:conn=3.86 -O analog  –continuous) <(sigrok-cli –driver=uni-t-ut61e:conn=3.87 -O analog  –continuous) > measure.csv

 

I’ll let you deal with the uber simple csv processing with octave or libreoffice calc (mV, mA range condition, etc…), as this blog entry is mainly used as a personal notepad.

Note: if you have trouble connected with sigrok, with an error. You may need to disable the power feature, with the script pointed by blog.philippklaus.de

#!/bin/bash
# see http://www.erste.de/UT61/index.html
for dat in /sys/bus/usb/devices/*; do 
  if test -e $dat/manufacturer && grep -q "WCH.CN" $dat/manufacturer; then
    echo "Suspending ${dat}."
    echo auto > ${dat}/power/control
    echo 0 > ${dat}/power/autosuspend 
  fi      
done