 new product introductions brought to you by digi key and a fruit this week is translated to what is like introduction npi this week well I'm excited to have a new vendor on npi I always love I mean don't get me wrong I love the STs and the TI's and the analog devices but once in a while you get something new tried semiconductor so this was featured on digiki.com slash new this is the TS4631 make sure you get the part number I because I have a couple in the family and this is an infrared light analog front end specifically for VR and AR uses so this company this is from their website for triad they're kind of like the specialty ASIC maker that makes the chips that are used for tracking devices and AR VR but also might be useful for other kinds of 3d tracking which we'll talk about so even if you're not like making an AR or VR product especially if you are this product might be interesting to you so the TS4631 is the latest in generation of their light digital converter and basically you know at the bottom right you see how you connect it up it's kind of the usage diagram you have this chip you give it a couple little passives you give it a big IR photo diode and then it can send the envelope and data from infrared lighthouse transmitters to a microcontroller ideally one that has you know wireless connectivity like Wi-Fi or Bluetooth or ZigBee that can then be used to track the item with millimeter precision in a 3d space like a room this chip is used primarily in the HTC Vive or Vive I don't know how to say it I'm gonna say Vive but I could be wrong the VR system that you can even see like there's these little divots in all of these little products and that's where the infrared receivers would be and then the two things and the top right and top left is a little square round-ish boxes those are what are called lighthouses and they look and some beautiful creative comments public domain photo the lighthouse they were just like a lighthouse works where inside is those boxes are these really bright infrared lights you don't see them with human eyes but sensors can see them and this is from the presentation from Alan Yates who who I guess worked on developing those base stations this is actually not what it looked like in the end this I think a prototype but basically there's like these really bright infrared IR lights and then there's X and Y scanning motors you can see like in that photo and the lights are on the top and the left and the bottom in the right are the scanning motors and the scanning motors rotate consistently I think like 30 Hertz and flash the infrared light around the room as a line so basically scanning the room and so what you would do is you know you connect the photo diode to this chip and it you know at first it flashes a the lighthouse flashes you know a big sync pulse to get everything to be like okay you know I'm about to send you this H this X and Y scanning pulse and then the sensor looks for the X and Y scanning pulse and measures how much time it took from the sync pulse to the X and Y pulse to get to it and then you know this is from the homebrew interface for these lighthouses from Tramble Hudson using some math and you can see like you know these envelope pulses on the on the bottom there you can see he's got four boards with the earlier version of this triad chip I think this he's got the TS 4231 you see little photo diodes the big silver things in the center there you get the pulse and envelope data and you can see it being graphed out and you know you do a bunch of matrix math which is documented here and in a couple of other libraries if you don't figure out the math yourself and then you can get within like a couple millimeter precision XY coordinates using only two lighthouses although you can have up to four and then you have a base station that you can communicate to and say I know where I am in XYZ space a lot cheaper than you would do with ultra wideband because infrared light is gonna be a lot cheaper than having you know four radio transmitters are trying to do time of flight and you can do time of pulse distance a lot easier than time of flight as well and this chip is actually this is this is the latest generation the 4631 build on the 4231 I saw this person who did some teardowns on social media of various controllers for SteamVR and this is like you know as of like 2023 this is what everyone's using this new generation's a lot lower power has like good deep sleep modes we can see it's like a very small chip very easy to use and then you can see the photodiode is much larger than the chip itself and even all the passives and this is a you know what you know basically I think chip with code compatible but a smaller die and lower power usage this is how it works and you know I think even Tramel Hudson in his write-up which I link to in the text for this video in this post he kind of shows like you could build this all with analog electronics but it would just really suck because you have to do like gain management and offsets and you know detecting the envelope detecting data coming out so it's nice about the TS 4631 is even if you have a powerful m33 microcontroller whatever you still want to have all of the analog stuff handled on this chip and done very small and very inexpensively and it's a point four millimeter BGA nine pin but thankfully the middle pin is ground which is shared with another analog ground thank you love that because it means you can do this on two-layer board without any like buried or blind vias even though it's point four millimeter pitch you know that that is not the issue it's usually getting that middle pin out but they made it really easy to integrate and then the two output pins that give you the envelope and the data are also used for the configuration so it uses I scored C there's like one 16-bit register that you can write to and this is you know the sleep modes the game modes very thresholds you can configure or you can use the defaults you do need to configure it to start like it won't just like boot immediately into usage because it starts up in sleep mode like normal sleep behavior you have to tell it to be enabled some mode one or mode two so you know you do have to use the I scored C even if you're not planning to use any of the other way distributes as I mentioned this is an upgrade to the 4231 I saw try and send me has a GitHub repo and they do have a library from a while ago for the 4231 the original version of this chip you can probably use it as the basis for your library on the 42 60 46 31 I also saw that's a lot of people doing cool DIY VR hacking with this chip and so you know I'm sure if you want to make an official product that uses the VR headset technology you can you know talk to try out or you talk to steam VR you can talk to HTC and you know sign developer agreement with them but if you also want to do do your own thing DIY something with AR or VR without necessarily going through the development process you can buy these chips and you know the stuff isn't under NDA it's fully publicly documented you can follow along with some of these projects and guys including this really cool white paper that basically shows how to make like a full 3D positioning system there's also from Cian Lorne he wrote that live survive which is a Python library runs on desktop that will do all the 3D calculations for you to create your own trackable objects without again having to purchase a track or you can make small ones that use your own technology stack in your own sensors so I think really neat so check it out it's in stock don't get any debt photo diode but very cool you know I think could be useful for drones could be used for interactive art could be used for like any internal tracking where you know the cost of the trackable device is you know can be made for under five dollars material all right and that's this week's on api