├── README.md
└── Esp8266_4051_Multiplexer.ino


/README.md:
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 1 | # ESP8266-4051-Multiplexer-Example
 2 | An example showing how to use a 4051 multiplexer with an esp8266 to connect up to 8 analog sensors.
 3 | 
 4 | Buy the Multiplexers here:
 5 | - [Aliexpress](http://s.click.aliexpress.com/e/qzNZrRZ)
 6 | - [eBay](https://rover.ebay.com/rover/1/5282-53468-19255-0/1?icep_id=114&ipn=icep&toolid=20004&campid=5338037665&mpre=http%3A%2F%2Fwww.ebay.ie%2Fitm%2F10PCS-IC-MUX-DEMUX-8X1-16DIP-SN74HC4051-74HC4051-NEW-%2F311503477945%3Fhash%3Ditem48870ddcb9%3Ag%3AXIgAAOSwnipWbBG4)
 7 | 
 8 | Buy the ESP8266 here:
 9 | - [Wemos d1 mini clone](http://s.click.aliexpress.com/e/uzFUnIe)
10 | - [Wemos d1 mini](https://www.aliexpress.com/item/D1-mini-Mini-NodeMcu-4M-bytes-Lua-WIFI-Internet-of-Things-development-board-based-ESP8266/32529101036.html)
11 | - [NodeMCU](http://s.click.aliexpress.com/e/AAyvJiA) 
12 | 
13 | Wiring: Wemos ->  4051
14 | ---------------
15 | D4    ->   S0 (A)
16 | 
17 | D3    ->   S1 (B)
18 | 
19 | D2    ->   S2 (C)
20 | 
21 | A0    ->   Common
22 | 
23 | 3.3v  ->   VCC
24 | 
25 | G     ->   GND
26 | 
27 | G     ->   Inhibit
28 | 
29 | G     ->   VEE  
30 | 


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/Esp8266_4051_Multiplexer.ino:
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 1 | /*
 2 |  ESP8266 4051 Multiplexer by Brian Lough
 3 |  
 4 |  An example showing how to use a 4051 multiplexer with an esp8266
 5 |  to connect up to 8 analog sensors.
 6 | 
 7 |  Wiring:
 8 |  Wemos ->  4051
 9 |  ---------------
10 |  D4    ->   S0 (A)
11 |  D3    ->   S1 (B)
12 |  D2    ->   S2 (C)
13 |  A0    ->   Common
14 |  3.3v  ->   VCC
15 |  G     ->   GND
16 |  G     ->   Inhibit
17 |  G     ->   VEE  
18 |  
19 |  4051 Option pins are then wired to whatever Analog sensors required
20 | 
21 |  One thing to note: say for example if you only require 2 analog sensors,
22 |  You can just wire up S0(A) and connect S1 & S2 to GND and you will be 
23 |  able to switch between option 1 and option 2 pins.
24 |  Same goes for up to 4 pins (just use S0 & S1)
25 | */
26 | 
27 | #define MUX_A D4
28 | #define MUX_B D3
29 | #define MUX_C D2
30 | 
31 | #define ANALOG_INPUT A0
32 | 
33 | 
34 | void setup() {
35 |   //Deifne output pins for Mux
36 |   pinMode(MUX_A, OUTPUT);
37 |   pinMode(MUX_B, OUTPUT);     
38 |   pinMode(MUX_C, OUTPUT);     
39 | }
40 | 
41 | void changeMux(int c, int b, int a) {
42 |   digitalWrite(MUX_A, a);
43 |   digitalWrite(MUX_B, b);
44 |   digitalWrite(MUX_C, c);
45 | }
46 | 
47 | void loop() {
48 |   float value;
49 |   
50 |   changeMux(LOW, LOW, LOW);
51 |   value = analogRead(ANALOG_INPUT); //Value of the sensor connected Option 0 pin of Mux
52 |   
53 |   changeMux(LOW, LOW, HIGH);
54 |   value = analogRead(ANALOG_INPUT); //Value of the sensor connected Option 1 pin of Mux
55 |   
56 |   changeMux(LOW, HIGH, LOW);
57 |   value = analogRead(ANALOG_INPUT); //Value of the sensor connected Option 2 pin of Mux
58 | 
59 |   changeMux(LOW, HIGH, HIGH);
60 |   value = analogRead(ANALOG_INPUT); //Value of the sensor connected Option 3 pin of Mux
61 | 
62 |   changeMux(HIGH, LOW, LOW);
63 |   value = analogRead(ANALOG_INPUT); //Value of the sensor connected Option 4 pin of Mux
64 | 
65 |   changeMux(HIGH, LOW, HIGH);
66 |   value = analogRead(ANALOG_INPUT); //Value of the sensor connected Option 5 pin of Mux
67 | 
68 |   changeMux(HIGH, HIGH, LOW);
69 |   value = analogRead(ANALOG_INPUT); //Value of the sensor connected Option 6 pin of Mux
70 | 
71 |   changeMux(HIGH, HIGH, HIGH);
72 |   value = analogRead(ANALOG_INPUT); //Value of the sensor connected Option 7 pin of Mux
73 |   
74 | }
75 | 


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