Mini portable power supply DIY

Here is a small DIY project, for a portable/bench-top power supply. We are not aiming for the best regulation, neither most power. But portability and bench-top estate optimisation.

This is based on the famous DPS3005 (about 25€)

Let’s 3D print an enclosure, found on Thingiverse:

And grab all the jelly beans needed:

Wire/crimp/solder:

Does work quite well:

With not much noise (static 100mA load):

And as I’ve this fancy portable solder iron with a bunch of li-ion cell:

It works on the road!

IKEA DIY FIP Webradio

We love to listen to FIP, as it’s a public radio, without commercials and not so much speaking.
Unfortunately, this radio is FM brodcasted in only few city in France, and here in Grenoble, the only way to get is internet.

So we built this small kitchen radio, music playing in 14 seconds, and quite pleasantly aesthetic, in the same line as my previous nixie clock.

The large solid aluminium knob with amplifier pot ON/OFF produces a comforting click to power ON/OFF the device or adjust the volume.
The shiny stainless steel button is for future upgrade to allow changing from few radio as currently only one is available.

Hardware part

Here are almost all the items needed for this DIY hack:

  • Ikea box (4€)
  • 4″ coax speaker (scrap)
  • 1″ tweeter (3€ on AE)
  • Rpi 3b (40€ on Farnell)
  • USB sound card (5€ on AE)
  • Stereo 5V amplifier (1€ on AE)
  • aluminium knob (5€ on AE)
  • stainless steel push button (1€ on AE)
  • C5 pannel connector for main supply (0.1€ on AE)
  • USB wall wart (scrap)
  • piece of 5mm plywood (scrap)
  • speaker fabric for front pannel (4€ on AE)
  • 30cm of leather belt (scrap)
  • washed nuts (1€ on AE)

A total of about 60€

Step by step assembly

Let’s remove the USB sound card along with the extra not needed capacitors and jack connector (desoldering station is realy a must here)

Make a slot for the micro SD card on the back: remember, the Wifi credential are stored here.

A XY table on a drill press was usefull, I didnt imagine bamboo being so hard to mill.

Piece of leather bought in Texas, this is what’s left from my buckle-less belt I made few years ago, it could be an entry someday.

With the washer nuts, it look nice.

The C8 pannel connector, wired to the wall wart.

Everything fitted in the box, held in place with double side tape (the brand Multicomp from Farnell is nice).

Adhesive rubber feet add an extra touch.

Piece of plywood for the front panel, black mate painted, with the speaker cloth.

Held in place with thin double side tape.

Finish

Let’s add a small tag to give some identity to this yet unbranded product. A nice friendly name, with our initials to personalize it even more.

Warm up kicad and start just a PCB without schematics, with a beveled edge to add a touch of design:

The result is very good, with this mirror finish!

Once glued on the product, it does raise the bar. (a pitty the manufacturing reference is on the front, next time I’ll do my artwork on the back, just to make sure it’s not on the front)

A quick video:

Software part

Download RPI image

Download a RPI image, in this case, I choose : pipaOS A lighweight, fast, Raspbian based distro for the Raspberry PI

Once the image unziped, copy to a fresh high performance micro SD card

sudo dd bs=4M if=./pipaos-tamarillo-4.7.img of=/dev/mmcblk0

in order to boost performances, I use a Samsung EVO+ for high performance for a very fast boot

ssh sysop@192.168.1.84 (password posys)

Connect to WIFI network

Rpi 3 rev B and Zero W have integrated wifi

Edit WIFI credentials

The file  /etc/network/interfaces should NOT be modified, as it’s overwritten at start.

Edit the file

sudo nano /boot/network.ini

To add your credential:

#
 # interfaces - setup your networking devices here
 #

auto lo
 iface lo inet loopback

allow-hotplug eth0
 iface eth0 inet dhcp

allow-hotplug usb0
 iface usb0 inet dhcp

# pipaOS Will automatically try to connect
 # to wireless ESSID "pipaos" passphrase "pipa123pass"
 allow-hotplug wlan0
 iface wlan0 inet dhcp
 wpa-ssid YOUR_SSSID
 wpa-psk YOUR_WIFI_KEY

High quality sound

Rasberry Pi have 3.5mm stereo jack output but the quality is pure crap, wondering why they even bother populate a jack.

So lets connect a cheap UBS sound card and check what appends

dmesg

sould display something like

[ 106.865142] usb 1-1.2: new full-speed USB device number 5 using dwc_otg
 [ 107.006372] usb 1-1.2: New USB device found, idVendor=0d8c, idProduct=0102
 [ 107.006387] usb 1-1.2: New USB device strings: Mfr=0, Product=2, SerialNumber=0
 [ 107.006395] usb 1-1.2: Product: USB Sound Device

[ 107.042816] input: USB Sound Device as /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.2/1-1.2:1.3/0003:0D8C:0102.0002/input/input1
 [ 107.105630] hid-generic 0003:0D8C:0102.0002: input,hidraw0: USB HID v1.00 Device [USB Sound Device ] on usb-3f980000.usb-1.2/input3

and

lsusb

will output:

 Bus 002 Device 009: ID 0d8c:0102 C-Media Electronics, Inc. CM106 Like Sound Device
 Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

 

Create startup service : webradio

sudo apt-get install mplayer
mplayer `curl -w "%{url_effective}\n" -I -L -s -S http://direct.fipradio.fr/live/fip-midfi.mp3 -o /dev/null`

Webradio player script

create non returning script:

sudo nano /home/sysop/webradio.sh
while true
 do mplayer http://chai5she.cdn.dvmr.fr:80/fip-midfi.mp3
 sleep 1
 done

create init.d service: webradio

#!/bin/bash
 #webradio daemon
 # chkconfig: 345 20 80
 # description: mwebradioapp daemon
 # processname:webradio

DAEMON_PATH="/"

DAEMON=/home/sysop/webradio.sh
 DAEMONOPTS=""

NAME=myapp
 DESC="My daemon description"
 PIDFILE=/var/run/$NAME.pid
 SCRIPTNAME=/etc/init.d/$NAME

case "$1" in
 start)
 printf "%-50s" "Starting $NAME..."
 cd $DAEMON_PATH
 PID=`$DAEMON $DAEMONOPTS > /dev/null 2>&1 & echo $!`
 #echo "Saving PID" $PID " to " $PIDFILE
 if [ -z $PID ]; then
 printf "%s\n" "Fail"
 else
 echo $PID > $PIDFILE
 printf "%s\n" "Ok"
 fi
 ;;
 status)
 printf "%-50s" "Checking $NAME..."
 if [ -f $PIDFILE ]; then
 PID=`cat $PIDFILE`
 if [ -z "`ps axf | grep ${PID} | grep -v grep`" ]; then
 printf "%s\n" "Process dead but pidfile exists"
 else
 echo "Running"
 fi
 else
 printf "%s\n" "Service not running"
 fi

Install startup service

update-rc.d webradio defaults

Start service manually

sudo service webradio start

Check startup time and performance

Startup time with RPI 3 B: Startup finished in 2.602s (kernel) + 4.386s (userspace) = 6.988s

Not bad at all for a full featured computer with wifi and usb audio

Adding the “send to” via email action to your Nemo/Ubuntu

How to get a “right click, send by email” menu in Nemo file browser:

Create the file:

.local/share/nemo/actions/thunderbird.nemo_action

Just cut and paste this inside that file and you’re done 🙂

[Nemo Action]
Name=Send by Email
Comment=Send by Email the files
Exec=thunderbird -compose to=,"attachment='%U'"
Icon-Name=thunderbird
Selection=notnone
Extensions=nodirs;
Separator=,
EscapeSpaces=false

 

Source: http://www.badpenguin.org/nemo-action-send-to-email

BROTHER DCP 9020CDW reset toner cartridge via the printer’s menu

Symptoms: the printer doesn’t want to print and ask for a toner change, no override available.

Easy procedure to reset toner counter: open the top cover, hold the * button for 5 sec (beside to keypad, not back-lighted, you can barely see it).

A reset menu appears and voila!

Fuck you Brother! My toner don’t need to be changed, my next printer wont be one of yours.

 

Source: https://printerthinker.com/brother-dcp-9020cdw/

Plastic part surface finish: please stop making mirror products

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!”

Linux/Ubuntu: Speaking clock with online TTS

As a followup of my previous article:

Ubuntu: talking clock every hours

4 years after the previous article, I still need this tool, but I wanted a more “natural” TTS.

So I’m using Voxygen, a natural TTS provider (very good for French), retrieving the generated voice with wget and the following command:

wget --quiet --no-check-certificate -O /tmp/clock_`date +\%-1H`.mp3 "https://www.voxygen.fr/sites/all/modules/voxygen_voices/assets/proxy/index.php?method=redirect&text=il est exactement `date +\%-1H` heures.&voice=Loic"

Here is the script to run every hours:

if [ ! -e /tmp/clock_`date +\%-1H`.mp3 ]; then wget --quiet --no-check-certificate -O /tmp/clock_`date +\%-1H`.mp3 "https://www.voxygen.fr/sites/all/modules/voxygen_voices/assets/proxy/index.php?method=redirect&text=il est exactement `date +\%-1H` heures.&voice=Loic"; fi ; mpg321 /tmp/clock_`date +\%-1H`.mp3 --gain 200

We will be using gnome schedule taks:

screenshot-from-2017-01-05-100935