8-bit LED Thing - This is pretty cool!

hello again from digicore things a few years ago when I was rediscovering my original Digital Electronics design and breadboard prototyping background I decided there was a need for a better LED indicator solution as most enthusiasts know it's quite common to hook up LEDs to your digital or microprocessor based Creations to easily see the status at key points within your circuit often jeel and line LED bar displays are used for displaying the state of parallel data and address buses or even individual register contents now although we love flashing lights and enjoy plenty of digital signal and register content visibility there are a couple of problems with doing this firstly seems quite common to Simply hook up an LED to a signal line which we wish to monitor for our current limiting resistor this unfortunately has the effect of significantly loading the signal that we are monitoring quite often beyond the data sheets maximum Source or sync current specification in addition if you add a number of LEDs to your creation you can significantly add to your Project's overall power consumption also creating unplanned voltage drops across your breadboards power feet wiring secondly hooking up multiple LEDs and current limiting resistors onto your circuit can be quite a tedious process with all of the resistors and hookup wires needed just to monitor a multi-bit bu or register so this is where the digicore things 8bit LED thing comes to the rescue it solves all these issues along with adding some cool additional capabilities on First Look the 8bit LED thing is a breadboard friendly 8bit LED bar display and a wider 16 pin Jewel and line package it is the same length as a jeel and line 16lb IC package with a 5 in width you can even place them end to end on your breadboard to make a 16bit or wider LED bar display you might say ha why don't I just use a regular jewan line 16 pin 8 LED bar display well if you did you would then need eight current limiting resistors additional wiring and face the signal loading and other issues I've just discussed the secret behind the 8bit LED thing is that it actually contains the brains of a tiny microcontroller making it a little smarter than your average LED bar display firstly to use it for displaying the status of up to eight to digal signals you only need to connect up the two power pins that is ground and your Project's 5V or 3.3v power line then up to eight digital signals can be monitored just by connecting to any of the eight pins along one side of the 8bit LED thing now apart from the ease of connection and no need for current limiting resistors the magic here is that each input presents as only a one microamp load to the signal being monitored yes I said that correctly only one microamp effectively there is no load impact on the monitor signal this is due to the fact that these sensing inputs are actually floating so there is no pull-up or pull down resistors adding load or having any impact on your circuit however because of this do note that if any of the eight to level sensing UTS remain unused then they should be tied to ground to demonstrate I'll grab a resistor bank and I'll actually tie the resistor Bank to ground as I pull down the signal then if I apply power we don't see any LEDs on but if I then get a jumper and connected to 5 Vols you can see as I jump each input pin the LED lights up in addition to this ease of use and virtually no load on the signals being monitored the display is also efficient as all the illuminated LEDs are CH plexed now this is only the start of the 8bit LED things capabilities you see this is just the 8bit LED thing operating in its default mode and there are another seven modes of operation you see on the other side of the display we have some more pins you already know about the ground and power pins there are also two pins to support microcontroller programming in addition there are also three mode control inut pins these mode pins have internal weak pull-ups enabled so by default with the pins not connected we are in mode 7even with all three mode pins pulled high so mode 7 is the default 8 Pin to sh level signal monitoring mode by controlling the mode pins we can switch to other modes including a mode that even turns the 8bit LED thing into a dice there are also various scanning display modes all are explained on the handout that comes of the 8bit LED thing one common use would be to just pull the mode one pin M1 low to cause the LED bar display to be a sweep scanner like the night rer car of the80s TV series Fame for indicating periods when your project is in standby as an example but I'm sure you can use your own imagination here's the scanner example I connect to ground and connect M1 pin there you go scanning mode I've actually been using a number of these 8bit led things with my own projects for several years now without previous L offering them as a solution for others to use you see I designed and twied them before Co hit but just when I was happy that they were complete and ready for others to use coover the global supply chain in the price of the microcontroller chips went up 10-fold recently I Revisited making another batch and I found that the component prizes had come back down so the 8bit LED thing was once again cost viable to offer for other users to have as much fun with as I've had as in as side the 8it LED thing also made a fun design project as they also represent the physically smallest microcontroller project I've ever made you can also consider the 8bit LED thing is simply a tiny SDM 8 microcontroller board which you could also program for your own projects as such I've decided to offer this in kit set form so you have the choice of using the beer MCU board for your own use or you can simply solder on the supplied LED bar display and the goldplated rout pin header strips to complete your own 8bit LED thing I've also added an assembled option where I can assemble them for you for a small fee I've managed to now make these available my tendy store and because it's common to use multiple of them on your breadbot projects I know I do I'm offering a four up price so you can have four for a reduced bundle price for fun I thought I'd also show you the testing check that I made to allow me to program and fully test each PCB prior to shipping or before the final LED bar display plus header pin assembly to program the microcontroller you can simply use an STD link version 2 USB programmer which is connected to the board with just four wires these are ground power reset and the SD single pin swi interface swim stands for single wire interface module if you don't already have an stlink version 2 programmer and you want one to play around with programming the microcontroller yourself I'll offer as an option the same STD link V compatible USB programmer that I'm using so you can get one with your 8bit LED thing from my tendy store okay so here is my 8bit LED thing programmer and test Jer I first made a 3D printed design inspired by the clip based Pogo pen programmers which I saw available online here's one that I designed in Fusion 360 but after finalizing the design I decided I wasn't happy with that approach you see as it is a clip design with just one spring poger pins do not remain perpendicular as you open and close the clip this is not ideal so I went about making a two spring design that would nicely raise and lower the pins in a constantly perpendicular fashion I was dreaming a pever mechanism raising and lowering the test pins but then I thought it would be much easier to Simply use a thread and a wing nut so after some design tweaking here is what I ended up with the good thing is that this has formed the basis for several different product testers here's an example of one of the testers for my t 866 EO Adept pcbs you'll not I even use an 8bit LED thing on this tester for showing the test results just uh mounts here for the J design the top part is identical on all of the testers and the bottom is simply customized to match the PCB outline of the device being tested using the PCB outline for the base shape makes it very easy to line up each PCB for testing the design also means it's very easy to correctly assemble the testers Pogo pins I simply need to insert the Pogo pins through the mounting Pooles Bolt the tester pcbs in place on the top piece and then with the tester tightened down the free Pogo pins nicely drop against the PCB outline base on the bottom piece it's then simply a case of soldering the top of the pins to the test PCB and they are all automatically in the perfect position to allow the PCB thickness of the PCB being tested to compress the Pogo pins on insertion so let's demonstrate the programming and testing of an 8bit LED thing board first I'll insert a new 8bit LED thing microcontroller PCB tighten down the Pogo pens then I plug in the SD link programmer to my USB port then with the St visual programmer software I just need to hit contrl P to initiate programming on success I can then disconnect and reconnect the stlink USB connection to reset the board and we can now test you'll note I have a jumper on the middle mode selection pin M1 which has the 8bit LED thing sweep scanning the display this initially tests the middle mode pin in all LEDs I can then move the jumper across to third mode pen for a single LED scanner and finally the first mode pin which activates the LED dice mode and we have two there are a total of eight modes but we only need to test that each of the three mode select pins are working finally with all the mode pins open we're in the default mode seven via the internal pull-ups where the eight inputs on one side are used for logic level sensing I have a pull-up resistor Bank on the testing board so by default all LEDs are on by jumpering each of the eight pins to ground I can test the L goes off which confirms each of the eight inputs are working correctly and we're done releasing the wing nut allows the PCB to drop out ready for testing the next PC ofp so in summary here is an assembled 8bit LED thing and here are the three components of the kit set version the surface mount device assembled programmed and tested microcontroller board a 16 pin 8 LED bar display and a 20 pin goldplated round pin header strip for cutting into the eight pin four pin and three pin strips you need for a final assembly to assemble you simply need to First solder in the LED bar display noting that pin one is indicated on the PCB is the beveled corner of the LED display then just solder on the header stps to create your completed 8bit LED thing ready to light up your projects with no the parts or current limiting resistors needed if you'd like one or a few please visit my Tindy store I hope you have as much fun with the 8bit LED thing as I have that's it thanks for watching

Channel: Digicool Things

Views: 3,236

Keywords:

Id: Qoe1tPHd92E

Length: 16min 55sec (1015 seconds)

Published: Fri Jul 05 2024