This is very well done and super clear. The application I have experimented with that led me to your video is creating a multi-cell battery discharge tester. I would like to use the multiple analog inputs measure the voltages of a number of 18650 lithium cells (recycled from a laptop, e.g.) under load over time, all at once. The challenge with these old cells for ebike and electric vehicles is getting batteries of equal capacity. There are easy ways to measure the capacity of single cells but not many cells at once. A multiplexer solution would allow testing of the many cells needed in a shorter time frame. Thanks for the excellent video.
This is a really good example of usage of a multiplexer. A lot of times when this is introduced its just introduced vaguely as "here is a multiplexer it has select lines and one output" instead of being given different applications like using it for driving LCD monitors, having multiple sensors etc. You can really appreciate the multiplexer in combination with microcontrollers.
I know this is not what you do anymore and that you are somewhere else on your path But daym!! You have the best walkthrough-how to-show and tell videos out there for someone learning this stuff. I wish I had found your channel years ago M8 🙂. Btw: Usecase. Monitoring a plethora of temperature and pressure sensors in a air to water heat pump system.
Hey Klaus, thank you for the comment. I've actually started a new channel that's more in line with what I do now: industrial automation. I guess all those years spent in embedded systems paid off. Really appreciate the kind comments.
I could see where I could use this to control a relay board - each relay controls a high power motor or other device. Also, to control camera by selecting one camera at a time - but you can use many cameras around your property with only one Screen output. Love this video !!
Great stuff for an Arduino beginner such as me. I plan to use Multiplexing for a project where I want to re create a track control panel for a model railroad.
Nice! Comes in really useful when you want to measure slower signals. From looking at the datasheet, the atmega328p can sample 15000 times per second at max 10 bit ADC resolution which can measure 1 x 7.5 KHz signal (good old Nyquist...should apparently sample slower than this to avoid aliasing but whatever.). Using your setup you can now instead measure 2 x 3.75 kHz signals, 3 x 2.5 KHz signals etc using only one pin! I would use this setup for a temperature measurement systems where you want to map the temperature at hundreds of different locations, for example to find where the heat is distributed in my apartment and find out where the heat is leaking out in winter :)
+Michael Segev very good point mike! I haven't really gone through the drawbacks of this setup, but you can't have "everything". This would be adequate for 90% of analog applications; not for high speed ones.
@@SolisPLC Since he mentioned it near the end of his video, I was referring to using it for analog outputs, not inputs. If you're driving the analog device, you're only driving it momentarily.
very informative keep it up .me as a beginner I see a solution looking for a problem😆 I wish if you could make more examples of where to use such a chip thanks
I was wondering. Can you use many resistive inputs on an arduino pin like for example for controlling the indicator function including left right and hazards on a vehicle?
If you are using push buttons you could also tie one side of each button to ground with a different value resistor. That way each button will have a different analog read value so you can diferenciate them. And only uses one pin
Great stuff, this just took me from 2 megas down to one, with a bit more PCB work. Next step for me is to figure out how to read 0-120v via an analog pin, once I can do that my project will be a go.
I believe a normal voltage divider would suffice if you are only measuring the voltage (The power draw is basically voidable). With 2 resistors, 120v to 5 volt would be divided with 1 resistor being 24 times higher than the 2nd ( 120 / 5 = 24 ). Using www.ohmslawcalculator.com/voltage-divider-calculator 2 resistors with values 27 Ohm ( Closest to 24 and under 5v ) and 1 Ohm would give a reference voltage of 4.286V between the 2 resistors. This output would be linear to the input!
I see a number of pins are used to address which input is being read at which time. I am looking into a project that may need many analog inputs (basically 10+ temp sensors). Obviously the way this system works won't scale well as more and more pins will be consumed to specify input addresses. I was thinking that combining multiplexers with shift registers, where the shift registers will specify which analog address you are wanting to read would massively reduce the number of pins needed. What are your thoughts on this? I was hoping to avoid having to use multiple controllers having to talk to each other to get a bunch more analog inputs.
I wander if you can tell me how can you make this counter to count 0 to 15 with 15 dip switches . Let say dip switch 1 dual led shows 01 then add dip switch 2 and show 02 and so on. Every time add on dip switch so to read 15 all 15 dip switches must be on. Please help.
Thanks for this interesting tutorial. If you please I just want to know what happens if two or more buttons are pressed simultaneously ? does it still reads the values or not ??
Great tutorial! Thanks so much! I have used the 74HC595N before for a series of digital outputs. With limited understanding of how they actually work. :D For a new project a need to read a series of analog inputs (where the 74HC4051 might come in handy). And also control a series of analog outputs (or digital with PWM). I am still struggling with the difference between mulitplexers like this and shift registers. How specific is their use? Could I use another one instead? Could I use this one for analog outputs, too? Or could I just the 74HC595N I already have for this job? Would be super greatful for any hints. THANKS!!!!
you look at "i" in binary form. for example if i=5 in the loop then it will be: [1]*2^2 + [0]*2^1 + [1]*2^0 which is represented as 101 or B00000101 in binary. So the goal is to activate the 6th (0..7) analoug in order to get it's value and the way to do it is by sending the S0,S1,S2=HIGH,0,HIGH to the multiplexer. The code resolves the logical statements: 1) B00000101 & B00000001 = B00000001, 2) B00000101 & B00000010 = B00000000, 3) B00000101 & B00000101 & B00000100 = B00000100. HIGH is actually the boolean True (or integer other than zero) and LOW is the boolean False (or zero) so HIGH && B00000001 is actually HIGH\True\"Integer other than zero" and HIGH && B00000000 is LOW\False\zero
I have a similar-ish setup, but I try to read really fast (38 KHz) and I’ve run into the problem that when I switch the input the first three to 8 readings (depenging on the impedance, using an impedence) becomes inaccurate (High spikes when switching). The strange thing is that it’s the first three readings no matter the read speed (9kHz up to 64 kHz) so I find it hard to believe that it’s the adc which needs time for charges to settle (since then it would take a fixed amount of time, not reads). Do you have any ideas what’s going on here?
Very cool explanation. You mentioned flow in terms of sensing and analog input. So if I had an array of flow sensors how would this count each pulse and increment a flow value?
+Clayton Allen If you have an array of analog sensors, you would get a reading from each one of them into the array. After that, you can use any of the values stored there for any purpose in your program.
With multible 16 channel multiplexer what is the maximum input (ie. Buttons) you can get on a audino board? Also do you need to consider extra power sources?
nice clear tutorial! would there be any electrical implications if I use two back to back to achieve routing from multiple inputs to multiple output? like increase in resistance, a decrease in the signals amplitude or maybe a delay?
Thank you for this video, it is really helpful. Just a question, can I see the value of analogue inputs at the same time, for example, if I press two bottoms simultaneously, will i see two values in the array?
Yes, each loop the code cycles through all 8 addresses in the multiplexer and grabs the current value so at the end/beginning of the loop you have an array with all of the values, so you will see a value for every button/input in the array
I have a real world use for this circuit. I have about 15 strawberry planters that will freeze this winter on my balcony if I don't do something. Bringing them inside is not a good option. I want to measure the temp of all my planters with an LM35 and I want to use some resistors to give them just enough heat so as not to freeze. It will get down to -10'F. So if I can use perhaps 5 watts worth of 1/2 watt resistors and keep the temp to about 37'F. I should be okay. In summary I need to Mux 15 Analog inputs and 15 digital outputs to the tune of perhaps 5 watts.
4052 has two banks of four inputs going to two output pins. (Or vice versa since the ins and outs are bidirectional.) You could read 8 values using two analog pins on the mC but that would require some wiring and code changes. While you would need two analog pins for input, it would require only two output pins for channel selection.
Good day, I came across your video, and thank you for the information, I am new to Arduino had done one or two projects but mostly learn as I go. I would like to ask if it is possible that you could explain how the binary bit of the code works, I understand the incrementale part of the binary sets, what I am wondering is how are you writing the correct addresses for each input? Are you just cycling through the bits and the chip only responds to the correct addresses or is there another thing going on that the addressing is precise? I hope this makes sense? Kind regards.
What happens when you push multiple buttons at the same time? Do you get a reading on multiple channels or just one?(whichever button was pushed first, last, etc)
There is a new approach in science for reading an unlimited number of sensors in parallel. It is called the photon-pixel coupling method. Maybe you can do it with an Arduino.
awesome job!...do you know of a way to use an arduino mega as a game controller? I didn't know enough and bought one not realizing they're not preprogrammed to emulate a controller like the teensy or the leonardo.
this tells the 74HC4051 which channel you want to listen to. In this example its channel 1. Then the 74HC4051 sends the value for channel 1 to the arduino
you look at "i" in binary form. for example if i=5 in the loop then it will be: [1]*2^2 + [0]*2^1 + [1]*2^0 which is represented as 101 or B00000101 in binary. So the goal is to activate the 6th (0..7) analoug in order to get it's value and the way to do it is by sending the S0,S1,S2=HIGH,0,HIGH to the multiplexer. The code resolves the logical statements: 1) B00000101 & B00000001 = B00000001, 2) B00000101 & B00000010 = B00000000, 3) B00000101 & B00000101 & B00000100 = B00000100. HIGH is actually the boolean True (or integer other than zero) and LOW is the boolean False (or zero) so HIGH && B00000001 is actually HIGH\True\"Integer other than zero" and HIGH && B00000000 is LOW\False\zero
how much minimum voltage can be read ? what is the resistance between input and output ( e.g Z and y0). why I asking this is as I want to interface multiple sensor to be read.
Just a quick question: I want to use the multiplexed for several moisture sensors, if I understand, the moisture sensors should be connected to the Y0-Y7, while S0-S3 to a digital pin each, Z to an Analog pin, and VCC to 5V pin?
can i read the value indivisuali from each pin ? i want to use multiple analog sensor but i have only 1 analoginput (Nodemcu esp8266).....want to extend ......................so thanks alot . can u make another tutorial on above topic ..............BIG HELLP if you do.
i did something wrong because my pins never read 0 even with a pulldown/up resistor. my wiring is probably wrong, i'll redo it. as to functionality and/or code, all working great. thank you!
Hello, I am looking to use an Arduino and a 74HC4051 to make the Switch of an RGB Scart between 8 Scart Inputs and 1 Scart output. Can you guide me on how to do this?
I am building a ckt to read and report various states (24VAC or 0) in a heat pump to an esp8266. Interesting chip. I am going to see what it's max input is. Maybe I can just rectify the single out to the esp.
If i press all buttons at once (or even more buttons, lets say 50 buttons) will the arduino read them all correctly or there will be some kind of error?
Hi, nice project and smooth presentation. Not sure you're still monitoring the comments on this video, but I try it anyway 🙂 What happens if you press 2 , 3, 4 buttons at the same time? if this works, what would be the maximum voltage you can receive? Thanks in advance for your answer
Hi Alexandre, it's me - Vlad! I'm onto a different channel that involved industrial automation instead of the hobbyist stuff I used to do. Pressing multiple buttons works, the drawback of this implementation is latency. In other words, you only read one sensor at a time, but you read them in sequence. So it's slower, but only uses a single pin on the Arduino. The voltage is 5VDC based on the Arduino, but I'm sure you can scale that if necessary.
@@SolisPLC Hi, thank you for your answer, I'll have a look at your other channel. I found some videos where the guys use registers shift modules, which allow for interesting multiplexing functions (ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-nXl4fb_LbcI.html from Kevin Darrah). In my project, I'm looking for a solution to read the multiple voltages of a battery pack made of several 18650 cells. The challenge is to stay below that 5V limit.
NISHIT MISTRY this would be a very interesting and potentially confusing block of code, I would imagine. Do you think it would require nesting multiple "for" loops to read the pins within series of mux?
Same MUX used on Akai Apc40 and my master fader is not working (only one). Try to find why is it so, cause a numbers of pots are connected to same mux that fader attached to..
hi all. new to this. can i ask if this will be better for back ground noise or worse. and if its one pin will this work on atTiny 8 pin. Thanks in advance, great vid,
hi nice tutorial is it possible to read analog values and put them seprately in a variable for uploading it to a iot cloud i am asking it for nodemcu cause it have just one analog pin
I'm a new comer to arduino and I need a shield to help control 4 different items with various power for each. I need to supply 10W to a pair of speakers each needing 5W and another 6W to another set of speakers each needing 3W. I also need about 2.3V for my VU meter by Great Scott with just a little more power for my lcd screen by arduino. I'm also including TDA7492P 25W+25W Wireless Bluetooth 4.0 Audio Receiver Digital Amplifier Board. So I'd like to add this features together with 2 analog inputs and 3 digital for on and off of whole system, switching from radio to Bluetooth, and one to vary the on and off of the VU meter
You cannot keep adding more sensors indefinitely. As you increase the sensor you increase the selector pins, which is basically your constraint on how many pins your micro-controller as. Just a side note there and to correct you.
Although that is true, you can always multiplex those as well or use an I2C selector IC to toggle those inputs that way. Nothing is ever "infinite" and you will run into power issues, communication issues as well as timing issues as you increase the number of sensors. That being said, you can definitely make it work if you take care of those problems.
how about reading 9 analog sensors if the 3 of them are voltage divider and the rest are acs712? as i know the voltage divider and acs712 have different codes in callibration? sorry, i'm just a beginner
With an Arduino Nano and a 4051 chip I was able to get 42 to 44 reads between 1ms interrupts. I had concerns about a potential error rate and dropped that back significantly for the final code.
I was thinking in using an arduino with multiplexed pots and switches, but I'm not sure if this boards tracks quickly enough or if it can take several control signals simultaneously without going crazy or mistracking sliders or pots, or jumping around values... Is it powerful enough to handle at least 16 muxed analog inputs, and 16 digital signals? :/
It is hard to answer the question without knowing what you will do with those signals. Obviously, the more inputs you have, the longer it will take the process. That being said, it's all about you application. You can be dimming lights with those pots and I can assure you that it will be fast enough. However, if you are trying to create a control system for a quadcopter for example, it may not be the optimal way. I'd say that you would need to try it to know for sure.
Hehehe, nothing too complicated. I need to convert each analog signal into MIDI and those digital signals as switches. Every analog input should be downsampled from 1024 to 128 values and assign each of those signals to a CC value, which is a ID for each controller...
Nice .. 👍😎 How can i use this with 74HC595 ... With 16x outputs LEDs ... 16 Switchs... 16x input and 16x outputs. How can i turn off and on each Led ... I have 2 x. 74HC595. With 16x Running leds and 10x different FX. Can i use this to control each FX ? And Each LED.. ? Thank you.. In Advance..
I'm not clear about how ur updateMux1 function works. for ex if I = 4 in the for loop, will S0 be set to 4 00000001 S1 -> 4 00000010 and S2 -> 4 00000100 sorry I'm a newbie and desperately want to know how multiplexer works with this code. can u pls explain?
if the i = 4, in binary system it means, that i = B0000100 ( big letter B - means binary system), and when you doing this operation: 4 & B00000001 - it means you doing this operation: B0000100 & B00000001 and you get the answer: B0000101, that in decimal system = 5 - the 5th input in MUX. Read more about binary system and binary operations - it help you to understand more. I hope you'll undertand my answer, as you can see, my English level is not so good.
Here it looks rather more like: 4 & B00000001 -> B0000100 & B00000001 -> B0000000 Mostly because '&' function leaves "1" only on bits where there was "1" in both numbers That way you get coding demanded by multiplexer like: S0 is 2^0 (so 0 or 1), S1 is 2^2 (so 0 or 2), and S3 is 2^2 (so 0 or 4) With that if you whant to get e.g. input 5 those operations will set S0 high, S1 low, and S2 high Hope it helps to understand
Can i connect three 74hc4051 ic's inputs in parallel?. Or what can i do if i want to use more than 1 multiplexer?. Because i've 24 analog inputs, and i only have these ics.
Just did this. Drive the select pins on multiple 4051s from the same output pins then attach the output from each to separate analog inputs. For each increment of your select pins (0-7) read one channel from each of the multiplexer outputs. With 8 analog inputs on a Nano, I see no reason not to be able to read 64 analog inputs using the same methodology. Be sure to consider pull down resistors on the select pins. After several trial and error attempts, ended up with 330K resistors to pull the pin low yet still allow the pin do drive the select pins effectively.
hello, great video,very inspiring, ...it gave me an idea. how can i control 8 Fotorezistors and log the lighting conditions over from each individual Fotorezistor(placed in different areas) using just arduino or just one raspberry pi ? basicaly i want to place 8 sensors around a small room and log the light intensity throughout a day. i'm thinking that neither arduino or raspberry pi has enough gpio pins... please help me understand how i could log data from 8 Fotorezistors at the same time placed in different areas.
i am going to read 4 sensor analog values into pin A0 for web interface its should read 4 analog sensor values one after another ......i need know what's the method for this and what are the changes i need to make in Coding
Can this read multiple analog inputs at the same time? (Like for example pressing two buttons at once and reading both of those values at the same time)
Santiago the Great I'm thinking yes, but not simultaneously. It has to cycle through the selection and it will send the data regarding the selected input, but it does that very fast, so it's almost like a simultaneous input
Good video but you don't press buttons and/or the potentiometer at the same time to show that it really is reading multiple values at the same time. Would be more impressive to do that.
Very nice. I am going to use this to put 54 thermistor into a beehive. I have bought 5x 12channel breakout, but after watching your video I wonder. Can i use 1 pin, connect to a 74HC4051 that connect to 8 74HC4051, that then each have 8 termisistor? I like to only use 1 pin on arduino :)
+ehonning You could do that, but keep in mind that you will need to toggle the channels of each of those ICs, so you would also need to come up with a circuit for that. Shift registers or digital multiplexers could be an option.
