Author: cyberboy666

Categories
shop

new product – artnet_led_mapper – an application for creating addressable led installations

this post is to announce the release of another new underscores product – the artnet_led_mapper – an open-source cross-platform application for creating addressable led installations

its the second software app we have released (after the similar tv_wall_mapper earlier this month) and the final in a series of open-source tools for video installation work based on my own art practice from the last year

project overview

artnet_led_mapper is software designed to help you to map arbitrary video onto an addressable led strip canvas – in this example (from the project demo video) i have arranged the leds into a low resolution led wall:

but you can map your video source on to any number of creative and abstract stage designs as shown here from the lateral movement club nights that inspired this project:

the software takes a video source (you can use webcams or external capture cards or video sent over NDI) and uses your user defined mapping to output art-net – a network dmx lighting protocol. this is combined with a hardware led controller to control the array of led pixels.

we recommend using our open-source hardware solution the lateral_led_controller although this software should work with any art-net compatible controllers

watch the full video where i demonstrate setting up the mapping for the led wall example:

background and motivation

as mentioned above this project was inspired by the installation work i did with lateral movement – a semi-irregular club night showcasing left-field & experimental dance music and light – you can find out more about the background to this in the artist talk i gave on it WORKS IN PROGRESS 04:

we ended up using touch designer to create the custom patches for this installation since my collaborators had a bit of experience in this. it worked well but was quite complex. also i needed to borrow their windows laptop to test the hardware on since i couldnt run it on my linux computer.

at this point i was already building a similar single purpose mapping application for tv wall installations and thought it could be worth forking that to do the same thing for led installations

resolume is also capable of outputting artnet for these kind of led installations. i will repeat the exact same points that i listed on the tv_wall_mapper blog post as to why i was motivated to create this alternative solution (since they all still apply to this app also)

we are happy to provide another light-weight, open source and cross-platform alternative to making video-art installations and exploring new ways to work with video and light!

same as the tv_wall_mapper this app is open source and available to compile yourself for free – you can also make a sliding scale donation (between 10-100euros) to support this work and gain access to pre-compiled versions that should run out of the box!

Categories
shop

new product – the lateral_led_controller is in stock now

a new circuit has been added to the underscores catalog – the lateral_led_controller – a hardware network interface for addressable led installations

this is another release in the series of open-source tools for video installation work i have been developing and is a companion to the artnet_led_mapper software that is also being released today.

the lateral_led_controller converts art-net sent over wired ethernet into the protocol used for addressable leds. it can be combined with mapping software to send arbitrary video onto an led strip canvas:

this circuit is based on the custom hardware i designed for lateral movement – a semi-irregular club night showcasing left-field & experimental dance music and light

i made a demo video showing how to use this controller to set up an addressable led installation like these – you can check it out here:

addressable leds

its currently compatible with the two main families of addressable led strips (but more can easily be added via firmware updates):

  • the WS281X (neopixel) which is a cheap but slow single wire protocol, which the controller can support up to 8 parallel outputs
  • the APA102 (dotstar) which is a faster two wire protocol – a single data line plus clock line can control up to the 2000 recommended pixels

motivation

this product is a bit different from the video instruments we usually focus on for underscores releases – unlike those, there are many led controllers already on the market. however when researching options for our club nights (just over a year ago now) we didnt find anything suitable in our price range.

all the existing led controllers we looked at were either:

  • very expensive professional gear
  • only supported a couple of universes (ie <500 pixels)
  • designed for home use with only wifi options ( we need a wired ethernet connection for use in a crowded venue)

i wanted to design a controller specifically made for the kind of video-art installation work we were doing

new alternatives ?

interestingly enough there does appear to be some more affordable options for generic wired ethernet led controllers coming out of china these days such as this H807SA (and a few others i could see on ali)

i have not tested any of these myself so do not know how/if they work – i would be curious to hear from anyone who has however!

regardless i believe it is still worth releasing open source and artist made alternatives where possible. the main advantage to using an open source controller is that we can fine-tune it to our specific needs rather than relying on a black box – this also future proofs us – if a better led strip with a new protocol comes out we can update the open-source firmware and continue using our existing hardware.

circuit modules in the design

one interesting thing about this hardware design is that it is made up of a few existing circuit modules. besides the WT32-ETH01 micro-controller there is also the MP1584EN_5v_stepdown module and the WeMos_CH340G_USB_to_SERIAL module:

the main advantage of this approach is that we can use smd parts while still keeping the project diy friendly. also sometimes it works out cheaper to source these premade modules than the individual parts since they are purchased and assembled in large batches and then resold. however it can feel more “hacky” and make sourcing parts for the project harder in the long term (if these particular modules become less available)

this project started as an adaption from a in-house one-off solution i designed and the use of these modules in it reflects this – if it proves to be popular enough and useful to others outside of this i may consider a future revision which is made up directly from the smd parts it needed – time will tell!

the local web interface

another cool feature of this controller is the local web interface for easily configuring network / led settings:

by joining a wifi access-point created by the controller we can access all the settings required on our computer / phone

i found this to be a nice way to configure a micro-controller without needing to edit code or dive deep into a tiny menu – im excited to use this approach again for other micro-controller projects i work on!

Categories
shop

new product – tv_wall_mapper – an application for creating tv wall installations

im happy to announce the launch of a new product for underscores : the tv_wall_mapper – an open-source cross-platform application for creating synchronized tv wall installations

although many underscores projects have software components to them this is the first purely software application we have released – its also the first of a series of open-source tools for video installation work that i have been working on inspired by my own art practice over the last year.

project overview

tv_wall_mapper is a software designed to help you create a synchronized tv wall effect – where many tvs are installed together to output different portions of a single cohesive video feed.

there are a few different hardware options (outlined in the project readme) that this app can work with to achieve this effect – perhaps the best being the use of off-the-shelf tv_wall_controllers such as these:

these kinds of controllers are designed for commercial spaces where multiple (expensive) bezelless tvs are used – however by using this software we can define a mapping so that any physical arrangement of tv’s can be used:

i made a tutorial video where i walk through the hardware/software options and show how to set up and map this demo tv wall:

inspiration and motivation

this project was inspired by a recycled tv wall installation we built for the dojo stage at Twisted Frequency Festival 23/24 – you can hear a bit more about this project in my WORKS IN PROGRESS 02 artist talk:

under the hood the video mapping is done using openframeworks + some glsl shaders (both things i had some experience writing for other projects)

it is possible to achieve this effect with existing projection mapping software – for our installation originally we were using resolume with the hardware controller to achieve this.

the main reason i have taken the time to polish and publish this little diy alternative:

  • i use pop_os as my daily driver and wanted an app that could run on this (which resolume does not)
  • resolume is proprietary and expensive – it is important to have open and accessible alternative tools for artists
  • building on the unix philosophy of creating software tools that are designed to do one thing well – this app aims to be simple and lightweight (you can always “pipe” video from other apps using NDI )
  • a nice side-effect of having a light-weight cross-compatible app is we can also run it on single board computers such as raspberry pi’s – commonly used for installation work

compared with hardware releases which are relatively easy to price (taking into account the cost of parts, labor, creative work and similar products on market ) it is harder to know how to price software -especially “small specific task” apps such as these. the code is open source and available via the github for anyone to compile for free. i have decided to also offer pre-compiled versions of these apps via the underscores shop for a small donation (a sliding scale between $10-100) hopefully this strikes a balance between making it accessible to those without the funds and also sustainable to invest our time into.

this kind of release is new for us and im very happy to hear any thoughts or feedback from those reading about it here

Categories
other

buying an oscilloscope for building and testing diy video circuits

all the circuits we design and distribute for underscores.shop are made to be diy and beginner friendly. a big part of this mission is to enable and encourage artists to engage with their own art-making tools.

often when helping people troubleshoot their circuits i am asked to recommend a digital oscilloscope they could get. also for my online class about making analog video synths on breadboard i would like to suggest some scopes that students could look into getting if they want.

in this post i will outline some of the features of a digital oscilloscope that make it useful for building and testing diy video circuits and then suggest a few options across a range of prices and feature sets.

main features to look for

  • the bandwidth – ie the the range of frequencies that it can accurately measure (this is rated in Hertz)
  • whether it has trigger modes – most modern scopes do
  • number of analog inputs
  • does it include a signal generator ?
  • does it include a multi-meter ?
  • what form-factor would suit your needs ?

my quick thoughts on these in general:

  • composite video uses around 4-5Mhz and vga @ 640*480 needs around 14Mhz so more than this is ideal for a scope to inspect video signals (especially hd ones) – however in practice i would rarely need to see all the details of the subcarrier or every pixel so you could definitely get away with less
  • triggering on the rising/falling edges is often essential to get a stable look at video signals – would recommend checking your scope can do this.
  • having two analog inputs can be very useful although this often increases cost as well – if you have the budget definitely go for this but don’t stress if not
  • signal generators can be useful for testing circuits and are fun to play with but not essential
  • a multi-meter is pretty essential for working with electronics – if you dont have one already then a combined meter + scope could be a good option for you
  • i like the small and portable kinds that run on rechargeable batteries but i also have a larger desktop scope that i mainly use.

ZEEWEII DSO154Pro 18M – cheapest option i recommend

i got one of these ZEEWEII DSO154Pro 18M from aliexpress for around 25 euros and was pretty impressed with the results – learning the interface is a bit clunky on lots of these machines but once you get the hang of it seems like a great first choice:

  • claims 18Mhz of bandwidth – at least in my tests inspecting a color-burst at 500ns divs it looked fine
  • triggers worked as i would expect
  • only has one input to the scope
  • has a built-in signal generator – this seemed pretty good:
    • i like that you can use it to generate really slow (0.1Hz) oscillations
    • would be nice if the vpp was adjustable but it is not
  • does not include multi-meter – which is fine for me i already had one
  • is very small form-factor – comes with rechargeable battery that lasts long enough

ZOYI ZT-703S – 2ch scope + multi-tool – looks promising

i have not tested these myself but have seen them recommended as good entry level-scopes online. you can get ZOYI ZT-703S on aliexpress for around 70 euros – so more than twice the price of the mini-ZEEWEII however:

  • 50Mhz of bandwidth claimed
  • 2 channels of analog input – very helpful for comparing signals etc
  • built in function generator (with adjustable vpp!) and a multi-meter in a nice portable form-factor

seems like quite a good option if you want 2 channels / need a multimeter anyway… they also have a 1 channel version the ZOYI ZT-702S for 50 euros however this only has 10Mhz bandwidth which is a little on the slower side – could be ok tho…

OWON HDS242 – a solid portable 2ch scope + multi-tool for a bit more

i picked up one of these when i needed a portable scope / multi-tool for some installations i was doing away from my bench. you can get the OWON HDS242 on aliexpress for around 110 euros (+20 euros if you want the optional signal generator also) – it is well made and easy to use. runs at 40Mhz and im sure is better quality than the ZOYI ZT-703S… however im not sure it is worth the almost twice the price with similar specs… especially for my uses as a secondary one – i might sell this and just use the ZEEWEII DSO154Pro for when im away from my bench going forward

a Rigol DS1054Z or similar second-hand ?

these Rigol DS1054Z are professional machines (with lots of features i never touch!) and mine has served me well for many years and will for many more i hope. i think they retail at around 440 euros but i got one less than half that price from a closing mens shed. (plus theres a well documented firmware hack to unlock extra bandwidth!) so always check out the second-hand market before buying anything new!

FG-100 – a cheap signal generator

its not a scope but if you want a cheap signal generator thats not attached to your scope i found these FG-100 DDS Function Generators on aliexpress for around 15 euros to be a good way to add signals to your circuits.

the interface to set the frequency value is awful but i really like how it has a knob for variable amplitude (up to 10vpp) plus another little knob for dc offset!

Categories
shop

new product – two_point_one_colorizer in stock now

i am happy to announce that the two_point_one_colorizer circuit based on Rob Schafer’s design is in stock now!

it is currently available as a diy kit or fully assembled and tested unit – bare pcbs will also be in stock soon (when my next pcb order comes in)

you can find all the source – schematics, gerbers and documentation on the project github page

theres some more written info about this circuit in an earlier post i made here

im not quite ready to stock front-panels in the shop yet – partially because im still working on how to expose interface parts like the slide switches that sit below the panel – however panel blueprints are available as files for those who want to diy some.

i will make a dedicated intro/demo video for this circuit some time in the coming month – in the meantime however you can see a demo of it in action in this artist talk:

finally i wanted to share some images captured from this circuit (these are all directly into a cheap easycap capture card) – in particular some examples of when it glitches / breaks (due to providing out of spec video):

some of these were captured while i was experimenting with different kinds of monostables to generate the colour subcarrier frequencies – you can see where the oscillations are too slow to be interpreted as colour as start to be interpreted as changes in brightness. i recommend using ic sockets for the parts U9 & U10 so you can experiment with this also!

Categories
update

a bug found in _transcribe_ code

_transcribe_ is a midi to rs232 bridge – for performance control of old video mixers and switchers – it has been available from underscores.shop since our launch in 2023.

by default _transcribe_ comes with mappings to control the panasonic ave55 video mixer however it was designed to be tinkered with and reflashed to map to other devices also (there is code available for mapping to other video mixers and switchers )

recently – due to some diligent debugging between myself and Robert LaPorte – we discovered there is a bug introduced when users modify the default transcribe code that maps the onboard din5-serial-midi input and output to different pins than how they are defined on the circuit.

a fix has been released now so if you are modifying firmware taken from github now this shouldnt be a problem. if you have a transcribe circuit and need any help updating firmware feel free to email me – i am happy to support you with this.

below i will explain what the issue was and why it went undetected:

mapping serial ports

the pro-micro-controller on the _transcribe_ circuit uses three different serial ports:

  • Serial – this connects over the built in usb-port and is used for monitors and debugging
  • Serial1 – this connects to pins 1=Tx, 0=Rx and is used to write to (and can also read from) the Rs232 port
  • AltSerial – this uses PaulStoffregens AltSoftSerial library to add another serial port to the pro-micro – it is used to read / write midi to the din5-serial-midi ports on transcribe:

the sparkfun pro-micro-controller we use is a breakout board for the ATmega32U4 – which is also the uC chip used on Arduino Leonardo

if we take a look at the pin table in AltSoftSerial documentation we can see that the pro-micro is not mentioned but that for Arduino Leonardo the serial pins are set to Tx=5, Rx=13:

however this is a problem for us since the sparkfun-pro-micro does not expose pin13.

in fact if we check _transcribe_s schematic we can see that din-midi-serial in and out are set to Tx=9, Rx=4: (D4 = 4 & B5 = 9)

inside the AltSoftSerial/config/AltSoftSerial_Boards.h L95-L105 we can see an alternative setup using timer1 and TX = 9, RX = 4:

and if i inspect this code on my local machine i can see that yes this config has been modified to switch the altSoftSerial pins to ones that we can use on a pro-micro board.

this means that every time that i upload firmware onto transcribes from my computer it is getting the correct altSoftSerial pin configurations, however – since this modified code sits in the AltSoftSerial package and not in transcribe code – any time someone else pulls down the transcribe firmware themself and uploads the code they are getting the default (unmodified) AltSoftSerial package so are getting that default mapping.

din-midi in and out worked on my machine! but wouldnt on anyone elses – it is my suspicion that only a fraction of transcribe users modify the firmware and also only a fraction use the din-midi ports (since it also supports usb-midi-hosts and usb-midi-devices) so i guess this bug went undetected until now.

the fix is quite easy – i only needed to fork the AltSoftSerial repo – you can see it here – cyberboy666/AltSoftSerial – make these config changes here – and then update the library being linked inside the transcribe code platformio.ini to point to this fork:

lib_deps = 
	felis/USB-Host-Shield-20 @ ^1.3.2
	blokaslabs/USBMIDI @ ^1.1.5
	https://github.com/cyberboy666/AltSoftSerial
	mathertel/OneButton@^2.0.2

one small thing is that now platformio may ask you to install git on your computer so it can pull directly from this repo – but this can be done quite easily by following the steps here

the main lessons on my side is to:

  • be careful modifying code that is not in your domain – if you are experimenting take notes of what you change and do a compete reinstall of packages before release
  • always test atleast once the install process from another machine – to eliminate any local changes not being reflected in source (i now how a windows ssd in my laptop i can boot into for these and other kinds of tests)
Categories
class

get tickets for my interactive online course building analog video synths!

limited tickets are available to purchase here for the next run of my 6 week online course a few foundations of analog video on breadboard

this course will start Monday 24 June and be weekly for 6 weeks (with 1 week break in the middle) – classes will be at two times:

EARLY – 09:30-11:30 EDT and LATE 20:30-22:30 EDT and also available as a recording (with help from the chatroom) if you cant make either

vga_breadboard_module and kit

this class is interactive, beginner friendly and one of a kind! – you will receive everything you need to build the vga video synths in the mail including the custom vga_breadboard_module only available through this class (one day i will release this also as a product in the shop)

the last time we did this class it was a lot of fun and i have made some cool new improvements to the module designs and class content since then – i really hope you can join us! please reach out to me if you have any questions

Categories
shop update

underscores.shop restocked & back from hiatus !

heres some new updates about whats been happening / whats coming up at underscores.shop

after a summer hiatus spent working festivals / installations in new zealand (+ quality holiday time with friends and family) we moved to melbourne, australia in march 2024

current catalog restocked

since being unavailable in the shop since late last year we now have back in stock as pcbs, kits and assembled units for:

plus at least a few of everything else (theres only a couple _transcribe_ units left and these are unlikely to get a restock since i have plans for a newer version of this that will supersede it)

raspberry pi zero w’s in stock

also for the first time i am now stocking a limited number of raspberry pi zero w for recurBOY – if you order one along side an assembled recurBOY i will solder on the 2×20 and 1×2 headers and test the complete unit before sending out to you

a few foundations of analog video on breadboard

i am currently preparing for the second session of my interactive six part online course – a few foundations of analog video on breadboard – the last one we did was a lot of fun – you get a kit with this vga-breadboard module and all the parts to explore a number of circuit designs online with me and others.

the next one will be running this june/july, likely followed by another session in september/october if there is still enough interest. people on the waitlist (found at bottom of the link above) will get offered spots first before a general release of remaining tickets after that – so sign up now to be part of the first release (tickets on sale end of april)

WORKS IN PROGRESS – artist talks / behind the scenes at underscores

i have been doing monthly online talks showing various WIP projects – theres still a couple more of these upcoming – you can find the details here – also check out the recordings of the talks that have been to get an idea of whats coming up:

scanlines x polyphase community showcase

every year in april we celebrate the birthday of scanlines.xyz community space and forum with an open-call and livestream of recent works – its a fun time to come together and share what everyone is up to! for this one we are combining our screening with the seasonal polyphaseportal.xyz showcase- check out the forum post / polyphase page for info on how to submit

upcoming releases

i have just built and tested the v1_0_0 release version of two_point_one_colorizer circuit – which i have written about already here – so this should be available in the shop within the next few months (just need to order parts, make kits, write documentation and film a demo video for this)

after this i hope next to release my installation-based software/hardware for tv wall and addressable led mappings followed by some new hardware designs tba

if you want to help support this research into developing open source video instruments please consider buying assembled units, spreading the word or donating directly

Categories
shop update

underscores.shop updates & summer hiatus

heres a short update about whats been happening and whats coming up here at underscores.shop:

summer hiatus

i have decided to effectively close the shop for 2-3 months over the summer here in new zealand starting from monday 27th november. i will be on and off the road for festival work and holidays plus moving out of my studio (and home) to relocate to melbourne.

there wont be any underscores releases or restocks during this time but for any remaining stock it will still be possible to place an order with the understanding that your items will ship by end of feburary 2024 at the latest – i will update here and on the mailing list when we get restocked and settled on the other side.

plans and projects for the new year

once we are settled and im back working in a studio space again i have a lot of projects i want to finish and share with you. heres a few of them:

works in progress

im also planning a monthly series of online talks hosted by polyphaseportal.xyz where i share and discuss various works in progress from behind the scenes at underscores.shop.

as you may have noticed by the sporadic updates, teasers and ideas thrown around here and elsewhere online, im much better at starting new projects than i am at following though, finishing and sharing current ones. im also not that comfortable with sharing too much about upcoming things publicly since it makes me feel bad when i cant meet the self-imposed deadlines or end up shelving them because i get overwhelmed. i want to get better at sharing the process and allowing room for feedback and discussions in these stages though. hopefully this informal format will help with this – would be nice to see you there!

Categories
design shop

designing and fabricating front panels for pcbs (using kicad and lightburn)

i’ve spend the last two weeks house-sitting at my parents place while they are on holiday. this has given me time to deep dive into some larger topics i have been meaning to get around to.

one of these topics was the design and fabrication of panels for underscores circuits (having unlimited access to a laser cutter over this time helped!). i made a half vlog / half tutorial style video to document this exploration – you can see on videos.scanlines or on youtube:

types of panels

sometimes i get asked if there are enclosures/front-panels available for the pcbs i sell (there actually have been a few community contributed designs for the recurboy and i_n_c_u_r circuits) but so far nothing from me. this will change soon with the addition of two enclosure options – stand-alone sandwich and eurorack front-panel for the following circuits:

  • sync_ope
  • recurboy
  • _rupture_
  • two_comparator_effect
  • i_n_c_u_r

originally i planned to prototype with laser-cut MDF (and share these files so others can laser-cut also) but only stock the FR-4 versions in the shop (since these would be cheaper and tend to look quite professional) – however after seeing the MDF i think i prefer them to FR-4.. i wonder if there would be any interest in stocking MDF (or even bamboo) lasercut panels too ?

euro-friendly designs

although definitely not eurorack modules themselves a number of these underscores circuits were designed to be euro-friendly, in the sense that you could mount them in eurorack case with the appropriate front-panel if you wanted to.

all the interfacing parts of these circuits are vertically mounted and the pcbs are at most 100mm tall. all circuits run on single-rail power (mostly 5v) but some have footprints for euro-power headers anyway and the others you could mount a vertical barrel-plug on the bottom of the pcb allowing a small eurorack-to-barrel-jack converter to sit inside your case and power from beneath:

as i mentioned in the video there are a few other things to consider when adapting to eurorack – the small slide switches i usually use sit a bit too low for comfortable switching (i would love to try 3d-print some switch-caps for these when i get a printer!) and i would recommend choosing longer shafts on the pots than the ones usually supplied with my kits…

its fun to see them mounted together in a rack like this however this conversion is not the same as an actual eurorack module version of these circuits – which i do plan to design one day (closer to that day now that i finally have a euro-case built) the true eurorack versions will:

  • use smd components and be designed to conserve hp
  • have interface parts chosen to fit panels better rather than prioritizing what is cheapest
  • layout of interface optimized for rack use
  • have proper eurorack power headers
  • hopefully expose some more of the controls with CV

my workflow for creating panels

this is shown with more detail in the video, but here is a written overview:

copy the pcb footprint into a new project and delete everthing except for the edgecuts, silkscreen and any footprints of interface parts

then replace each interface footprint with a edgecut hole to access it from the panel (based on a table of known hole sizes)

arrange the silkscreen however you want the panel to look – 3d viewer in kicad is useful!

when you are happy with how the panel looks you can export it – use the usual GERBER export if you want to get it fab’d in FR-4. my method for getting designs into lightburn was to first export from kicad as SVG and then open these SVGs with inkscape and save a copy as DXF (it seems like lightburn didnt like some of the SVG format that kicad creates)

once in lightburn put the edgecut and silkscreen imports on different layers – you can add thickness to the silkscreen using the offset tool

then set your laser speeds, check the material is lined up with the cutting area and make the cut!