Esp8266 relay board schematic
The device should be perfect for use in simple IOT projects which require controlling household AC power. There are routered slots between the high voltage PCB traces for circuit isolation and arc-over protection.
Transient voltage suppression is incorporated on both the board power supply and the photocoupler see description below input line. The device requires a power supply between 7 and 30V DC. I unsuccessfully attempted to run it with an inexpensive 5V, 2A wall-wort, even though the onboard MP buck converter is rated down to 4. I did get it to operate successfully using a 9VDC wall-wort.
The good news is, programming the module is very easy, as I discuss later. I also found the overall build quality of my device to be above the typical level found on ebay-sourced Chinese electronics. The ebay listing contained a link to a zip file, entitled Udatasheetwhich contained example programs, schematics, and a Chinese manual.
More information can be learned from a quick study of the schematic and the board itself. Module Description The Chinese manual presents the following limited module description:.
I was easily able to connect a 9V power supply to the A-B connector see above picture and connector description and control the device via WIFI. My device responded to the supplied password of yunshan Once a connection was established, I simply entered the IP address of Once there, I was greeted by a Chinese web page, the translation of which appears below.
From this webpage, I was able to open and close the relay. The status of the GPIO5 optocoupler input is also displayed on this webpage. On the lower left portion of the PCB is a section that grants access to the ESP pins for programming see the above photo. These same pins are also useful for TTL serial output purposes debugging, etc.
Separate 2 and 3-pin headers will need to be soldered into these connector holes labeled P5 and P6. A very good introduction to the ESP module can be found here. Hi Jim, her article gives me hope. Try now for several days to find a solution to reprogram this circuit.Watch the following video tutorial or keep reading this page for the written instructions and all the resources.
A relay is an electrically operated switch and like any other switch, it that can be turned on or off, letting the current go through or not. It can be controlled with low voltages, like the 3. There are different relay modules with a different number of channels. You can find relay modules with one, two, four, eight and even sixteen channels.
There are relay modules whose electromagnet can be powered by 5V and with 3. Using a relay module with a different number of channels is similar.
The two connectors with three sockets each on the left side of the relay module connect high voltage, and the pins on the right side low-voltage connect to the ESP GPIOs. The relay module shown in the previous photo has two connectors, each with three sockets: common COMnormally closed NCand normally open NO. The low-voltage side has a set of four pins and a set of three pins.
The signal you send to the IN pins, determines whether the relay is active or not. The relay is triggered when the input goes below about 2V. You should use a normally closed configuration when the current should be flowing most of the times, and you only want to stop it occasionally.
Use a normally open configuration when you want the current to flow occasionally for example, turn on a lamp occasionally. That means the relay electromagnet is directly powered from the ESP power pin, so the relay module and the ESP circuits are not physically isolated from each other.
ESP8266 and relay board
Some ESP pins output a 3. This may be problematic if you have relays or other peripherals connected to those GPIOs. Connect the relay module to the ESP as shown in the following diagram. The diagram shows wiring for a 2-channel relay module, wiring a different number of channels is similar.
Misuse can result in serious injuries. While programming the ESP or wiring your circuit make sure everything is disconnected from mains voltage.The missing element in trying to make this device work was the concept that you control the relay by transmitting serial characters from the ESP rather than controlling an OUTPUT pin.
There is a STM8 micro controller on the board. Why do this? I wanted to test my relay module to see if it was programmed since it was obviously a clone.
And it worked! Then plugged the ESP into the HW, applied power and the relay will happily turn on and off every second forever. The ESP is quite clever and can be loaded with some off the shelf firmware that does WiFi and can listen for a TCP connection so you could open a socket and send the four byte sequences from a machine on the same network.
Note that there are two versions of the ESP You need the bigger memory for Version 1. Can you elaborate on how you uploaded the sketch? USB adaptor must be in programming mode. You can now program the ESP I did at home and its working. Just follow the steps of the link below:. The only data connection from the ESP is serial out so there is no way of monitoring the relay state.
You could connect the relay driver line to a spare input line on the ESP assuming it never gets more than 3. You are commenting using your WordPress. You are commenting using your Google account. You are commenting using your Twitter account.ESP8266 and Relays - Unsolved Mystery
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This is a rather general request for guidance in the design of a printed circuit board based on ESP The resulting device should run autonomously on a solar charged 12V battery.
Any critical notes or suggestions on this plan? Thanks in advance, Vax. NodeMCU is one.
Options 2 posts Page 1 of 1 2 posts Page 1 of 1. Return to Newbie Corner. Who is online. In the industry I am involved in the actuator have[…]. Still prefering esp to ESP32 for most applicat[…].
Well, I already tried several options: - 9V batter[…]. I think you will need to give some more informatio[…]. I want to build my own USB device The esp a[…]. I am running a generic ESP board connected to […]. Thank you very much. I really appreciate your kind[…]. I have been programming in Basic for many years an[…]. Thanks both for the links and suggestions. I am lo[…]. I am an ESP noob Hi Friends! My apologies, because I'm sure someone[…]. No one use those base on esp?
They are super c[…]. Hello everyone, It's first time project with ESP8[…]. Exactly the same question has been previously po[…].Even though this perf board served the purpose of using the ESP on a Breadboard, I still had to connect the level converter resistors, push button to reset the module separately.
The pin description is already mentioned in the earlier tutorials. The GPIO0 pin is connected to the center terminal of a two way slide switch. Next is the communication pins i. TX and RX. This image is just a reference and you can draw the schematic as per your convenience using the circuit diagram. After the schematic is completed, the next step is to proceed with the actual PCB Design.
Once again, this is not a great design but it serves the purpose. I would not repeat those steps and instruction as you follow them from that tutorial.
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Relay are powered with a different power source than NodeMCU. When I execute the URL: I have several of these modules. They have an optional opto-isolator built-in, but you have to remove the jumper to use it. Now your relay coil s will be powered by the 5v plug, but the relay's logic and control are handled by the MCU.
The relay has no reference for what the voltage from the NodeMCU is. Since the power supplies of the two devices are isolated from each other; the laptop may not be isolated itself, but the battery certainly should be you can and in fact must connect the grounds of the relay board and the NodeMCU together. If neither power supply is isolated or if you are unsure if they are isolated then you should use an optoisolator in order to prevent potential power issues.
I believe the problem could be that the relay is 5v but the signal coming from the NodeMCU is 3. You may need do something like boost the signal to 5v or implement a logic level shifter, for example.
How are you powering your ESPE? This is not included in your diagram. This relay module works differently. Sign up to join this community. The best answers are voted up and rise to the top. Home Questions Tags Users Unanswered. How to make a 5-volt relay work with NodeMCU? Ask Question. Asked 3 years ago. Active 6 months ago. Viewed 59k times. I have hooked up 2 channel 5-volt relays with NodeMCU v1. But neither of the relays turns on.
Please help. Ciasto piekarz Ciasto piekarz 1 1 gold badge 11 11 silver badges 23 23 bronze badges.Did you use this instructable in your classroom? Add a Teacher Note to share how you incorporated it into your lesson. Relay is basically act a switch between electrical load and NodeMCU.
Relay have coil which is energized by 5v, when coil energized switching action takes place, based on NO-NC configuration.
If relay is NO configuration then when coil is energized switching action takes place from NO-NC then load will be connected. You can tinker with it if you like based on the application, or just use it as it is.
I hope you enjoy it as I enjoy making it and documenting it to show and tell to other fellow makers here. Question 3 months ago.
Hi, there is a way to prevent the relay from switching to NC and then back to NO when the nodemcu is turned on? Reply 6 months ago. Use low level triggered relay. So you can try using these pins for controlling your relay board if you don't wish to buy a low level triggered relay module. One is high level triggered as used in this tutorial and another is low level triggered. The main difference lies in its working.
Many relays draw more than 12mA. Question 1 year ago on Step 6. Question 1 year ago.
ESP Relay Board Hardware
Answer 1 year ago. By CodeChamp Follow. More by the author:. About: " Work until you no longer have to introduce yourself " Show some love on Instagram it. Hello Makers! I hope you know what is an Relay Module. Have you wondered how the relay module works? Add Teacher Note. Relay is a electrically operated switch. The relay uses an electromagnet to mechanically switch electric appliances.
A relay can be operated by a relatively small electric current that can turn ON or OFF a much larger electric current. Connections are very simple, initially you need to power-up the Relay Module. That's all makers!