The VanMeter is a little add on for my camper van for measuring the power consumption of up to four different things. Here I am using it to measure the power of all the loads in my van, the solar panel power and the power of the 230V charger. There is another channel which is currently unused - or as you can see in the end of the video, was used to measure the correct voltage (differential measurement) of the solar panel. Unfortunately I didn't find the solution so far, but I would be happy if you have a hint for me.There are two more things which I haven't shown in the video. The first thing is that I have used the ESP32Remote ( https://youtu.be/5vRy--YCx7k ) as a remote display next to the phone APP. The other thing is that the VanMeter can not only measure power consumption, but also is able to control up to eight different outputs. The pinheader on the right side of the PCB is optimized to be used with one of those eight channel relay boards. These can be used to control lights, outlets, pumps, heater elements or whatever you want. Something like a smartvan.As you have probably noticed, this build is still a work in progress and some features are not yet implemented. Some other things will be added to this board in the future. So stay tuned!

The gadget in this project is the deliverable of the course "ESP32 Unleashed".This gadget is a learning opportunity for several technologies and skills. Here's a summary:Learn how to program an ESP32 board using PlatformIO and Microsoft Visual Studio Code.Learn about persistent storage in EEPROM, WiFi communications, MQTT, SPIFS, watchdogs, task scheduling, syncing with an Internet clock, and much more.Learn how to interface with popular IoT services such as Google Assist (for voice commands), If This Then That, and Adafruit IO; use these services to build modern IoT applications.Learn how to create a graphical user interface, refresh a color TFT screen, and detect touch events.Learn the C++ basics necessary for writing non-trivial firmware.Here's a video demo of this project:I have designed the PCB for this project using KiCad.A student of the course, Daniel (Meridian, Idaho, USA), designed the 3D printed case and shared it.Doesn't it look great?I have attached my IoT gadget to one of my light stands, so I am not using Daniel's table base.You can learn how to create this gadget from the ground up in my course ESP32 Unleashed.

Welcome to my ESP32 based Industrial RS485 Gateway project. This project will be exciting if you have never heard of any Industrial Gateways.If you are wondering that what this gateway thing is all about, then stay around we will explore that soon.What is an Industrial Gateway?In lamen term an Industrial Gateway has mainly these objectives to be fulfilled.It should sustain the Industrial Environment.The device should be able to communicate with other Industrial devices such as VFD, Energy meters, Multifunction meters, inverters, etc. And most important it should talk to the internet. That's all you need now I think it should be clear that this device act as a gateway between the internet and other industrial devices.For communicating with different Industrial devices there are different industrial protocols such as Profibus, CAN, Profinet, AI bus, inter bus, and a lot more.But in this project, we will be using a famous protocol named Modbus and it works on the RS485 serial bus. We have one RS485 Port on our device therefore we can use Modbus RTU, Modbus ASCII, and with WiFi and ethernet, we can use Modbus TCP IP.To know more about Modbus you can check out Simply Modbus they have covered everything. Key Features:It supports industrial voltage levels up to 6 - 35Vdc.Onboard Wi-Fi and Ethernet for Internet Connectivity.Ethernet 100Mb interface.ESP32-WROOM-32D WiFi/BLE module. (Dual-core capabilities).USB connector for easy Programming ESP32 using Arduino IDE. Half-duplex RS485 Communication port.Onboard EEPROM IC for storing data.Automatic data flow control for RS485.Two Programmable LED indications. (I used them as Tx and Rx LEDs)Selectable RS485 transceiver voltage level. (5v & 3.3v)Industrial Enclosure with DIN mounting and compact size of PCB.What can be done with this project?Industrial Energy Meter MonitoringMost of the Industrial Energy utility meters have RS485 communication available. Therefore we can read data from energy meters such as overall industry unit consumption, power factor, frequency, total active or reactive power consumed, and more.After reading the data with the device we can send it to the cloud using MQTT or any other protocol easily. And you can display it in many open source app such as the MQTT dashboards, Blynk, or you can use Adafruit IO or you can build your own dashboard.Monitoring and controlling Solar InverterNowadays all solar inverters come with RS485 capabilities and a few of the inverters also provide functionalities such as ON-OFF operation over RS485.Our RS485 gateway will directly connect with such inverter and will communicate with the inverter and we can easily get the live status of the inverter such as PV voltage, all MPPT voltage level, unit generated, current output per phase, and different Errors also. Additionally, if your inverter support controlling, you can turn ON or OFF your inverter remotely with this small gateway.Live Industrial Temperature and Humidity valuesIn many industrial areas, they install Temperature and Humidity sensors for controlling the overall temperature of the area to a set value. Such sensors also have RS485 communication and we can get live data of that sensor in the palm of our hand with this gateway.We can also program it with alert values such as temperature rise above 65°C then send an alert via email, SMS, or in App, etc.Monitoring Pneumatic Pressure and Flow RatePneumatic systems are widely used in Industries to create controlled mechanical motion or force. And pneumatic systems operate with air and there are mainly two parameters in consideration flow rate and pressure for calculation of air consumption or air loss calculation.Above is the pneumatic pressure and flow indicator and has an RS485 port. We can now easily calculate and monitor very precisely with the RS485 gateway. Monitoring MFM (multi-function meter)Multi-function meters are used as sub-meters in industrial panels. MFM is used in parts like they install such meters for each section/machine part of their industries. So that they can observe particular machine consumption, efficiency, and more. Here is a live feed of an MFM meter to a mobile device by using an IoT RS485 gateway.These meters give perfect insights into the overall operation of the industry. As they can measure all important electrical parameters such as 3-phase voltage & current, active & reactive power, power factor, frequency, Kwh, and etc.I have seen industries that have more than 120+ such small meters. Here is a glimpse of an industrial electrical panel room full of multi-function meters, and they have 5 such big panel rooms. Hence installing RS485 gateways in such cases are most reliable as they are small, cost-effective, accurate, and provides lots of useful information about an electrical network in industries.If you want to monitor or control such RS485 devices then you will need a Modbus register map data of a slave that you want to monitor or control. Most probably this will be given in the App note of the slave device for the RS485 communication port.As a starting point for multifunction meters, you can check out the Aggsoft website they have a list of many different MFM from different companies with their Modbus register table ready for you.Apart from this, I have also controlled a VFD (AC drive) over RS485 with this gateway.As we see the possibilities with such small devices are limitless in industrial use cases.Exploring PCB componentsDC-DC Buck ConverterAs industrial standard voltage level here in India is 12Vdc and 24Vdc as most of the automation devices such as HMI, PLC, etc work on this voltage level.Therefore our device needs to be operated perfectly at such voltage level to fulfill the industry requirement. In order to do it efficiently and in a cost-effective way I have chosen to add a DC-DC buck converter onboard as a primary voltage conversion. I have used a converter name XL1509 in the project. XL1509 comes in mainly 3 different varients 3.3v output voltage (XL1509-3.3) 5v output voltage (XL1509-5) adjustable output voltage (XL1509-ADJ) The converter can provide 2A of constant current output that we do not need. And it operates at 150KHz switching frequency.In my case, I am converting the high voltage DC supply to 5v as a primary conversion. Therefore I am using the XL1509-5 variant for this.And it needs very few external components such as Input and output bulk filter capacitors (Electrolite caps 470uF - 330uF) one Inductor (47uH - 68uH) one Schottky diode (SS34) That's all you need for a converter and for achieving proper results out of it minor tweaking with inductor and capacitor values is needed.The PCB layout plays a critical role in such converters such as feedback path to the converter IC should be short and away from high-frequency switching, proper heat dissipation should be kept in mind, and more. Secondary Voltage Conversion We still need a 3.3v level to run our ESP32. Therefore I have used a famous LDO that ESP32 development board has AMS1117-3.3.It also comes in different output voltage and current variants. I have used 3.3v and 1A output variants in this project.USB InterfaceTo minimize the overall BOM price I chose CH340 as a USB to TTL converter as CP2102 price is a little high and I have sufficient space for CH340. Mainly two types of CH340 IC are famous CH340G and CH340C both have the same footprint and functionality. The only difference is that CH340C does not need an external crystal oscillator. And I have added ESP32 auto-reset circuit so that it is super simple to program the device using an Arduino IDE.And for a robust connection, I have chosen USB type B as it is big and has a stable fit when compared with micro USB or other types when compared with price.Ethernet InterfaceFor ethernet capabilities, I used a LAN8710A chip also known as Single-Chip Ethernet Physical Layer Transceiver (PHY).This IC follows 10/100BASE-T standard and as per the datasheet it can go up to 100mbps data speed (have not tested it at max speed as I do not need it if someone has used it at max speed leave a comment down below)Also, this IC has a build-in Two status LED outputs for the Ethernet connector.Using it in Auto-negotiation enable modeRMII configurationSMI address: 0x00And for the Ethernet connector, I am using an Hanrun HR911105A connector with magnetics.RS485 InterfaceRS485 interface uses differential voltage for error-free communication. Therefore we need to use the RS485 transceiver IC that will convert normal TTL signals to RS485 differential voltage signals.Shortlisted two famous transceiver ICMAX485 (works at 5v input supply)MAX3485 (works at 3.3V input supply)Initially, I used MAX485 without worrying that ESP32 GPIO is at 3.3v logic level and luckily it worked like charm, and non of the ESP32 get damage and they are all still working fine.But after a while, I discovered MAX3485 that supports a 3.3v input supply and now I do not need to worry anymore. (And now I have an SMD jumper JP2 for selecting input voltage given to this RS485 transceiver)Also, I have used a simple transistor logic for Automatic Data Flow Control for the RS485 transceiver. If you need to control the flow with software you need to remove components R4, R5, and T2. Now short the JP1 jumper and Flow control Pin will connect to GPIO2 of ESP32.RS485 is used for long-range wired communication and I personally have tested error-free communication up to 1Km with a baud rate of 9600. I have used standard twisted and shielded pair of RS485 communication wires from the Belden company (3105A )We can read/write up to 32 slave devices using this RS485 transceiver IC. All slave needs to be connected in a daisy chain for proper communication and all slave should have unique slave IC for avoiding clash in communication between master and slave. If communication distance is small then termination resistor Rt is needed of 120ohm and for long-distance, it can be omitted. RS485 Bus ProtectionFor protecting the RS485 bus I have used a small SM712 Series 600W Asymmetrical TVS Diode Array. SM712 is specially designed to protect RS-485 applications with asymmetrical working voltages (-7V to 12V) from damage due to electrostatic discharge (ESD), electrical fast transients (EFT), and lightning-induced surges.As per the datasheet, it provides the following protections-ESD, IEC 61000-4-2, ±30kV contact, ±30kV airEFT, IEC 61000-4-4, 50A (5/50ns) Lightning, IEC 61000- 4-5 2nd edition, 19A (tP=8/20μs) If more lightning protection is needed then SG6 and SG7 SMD Gas discharge tubes from LittelFuse can be used.Onboard StorageIn case there is no internet availability for a while and the monitoring data is important then we have onboard EEPROM storage for that.I have used AT24C512 EEPROM IC from Microchip which provides us an additional 65536 bytes of storage memory.Electrical Enclosure For Industrial use, the enclosure should also meet the industrial requirements like It should have DIN rail mount capabilities.High temperature sustaining capability. (-40 °C ... 80 °C)Proper IP ratings. (IP20)Proper ventilationTherefore after a lot of searches, I found a perfect enclosure that I was looking for the project.The enclosure that I used in this project is from Phoenix Contact. They have a huge selection of industrial-grade enclosures. For the base, I am using 2200474 and for Top, I am using 2201770.Here is the 3D animation of the overall project with the electrical enclosure. Want to play with a 3D model then try out this.Future ScopeThere are few things that I would like to include in this project in the future. Add Isolated Power Over Ethernet functionality (POE).Add an Isolated DC-DC buck converter for more protection of the device. (But it is not needed if we are using a proper SMPS).Add additional RS485 port. As one bus only supports up to 32 devices.The current version has a 120ohms termination resistor in the RS485 port. Would like to add one switch or jumper to turn ON and OFF the termination when required.Add a few high voltage DC IO pins.Add one onboard relay which can be programmed to turn ON heavy load such as AC alarm in fault conditions.Configuring Wi-fi CredentialsI have used ESP touch (SmartConfig) for easily configuring the WiFi credentials in ESP32.once It is configured I store them in ESP32 non-volatile memory so no need for reconfiguration.For doing so I have a step-by-step guide on using SmartConfig in ESP32 check it out.Also, you can check out my website TechTOnions.com for more such projects GalleryHave few more pics to show and now I am out of words so adding them here have fun.

Welcome to my new Weather Widget Project. Earlier I have posted an article on the weather widget, that uses a 0.96" OLED display to display the weather parameters. The main problem in the earlier version is that the display is very small in size, so you have to come very close to it for reading the parameters. That's why it was always in my mind to upgrade it to a larger color display with a nice 3D printed enclosure.In this post, I will show you how to make a Weather Widget by using ESP8266 and a 2.8" touch screen display. The device retrieves localized weather information from https://openweathermap.org/ by WLAN and displays it on the Display module.Visit my website for more interesting projects: https://www.opengreenenergy.com/The Widget displays the following things:1. Current Time with Date2. Current Day Weather Information like Temperature, Pressure, Humidity, and Rainfall.3. Future forecasting for 7 daysCredit :I would like to give credit to my friend Dani Eichhorn who did all of the programming parts. He is updating the software on his Github page regularly with new features. You can visit SquixTechBlog to see more projects on ESP8266.Prepare the Wires:My plan is to place the weather display circuit inside a 3D-printed enclosure. But the enclosure that I am going to use is very compact, and there is little room to keep the Wemos board along with the connecting wires inside the housing.So, we have to select thin wires to make the connection between the display unit and Wemos Board. Here, I have selected 30 AWG single-stranded wires.Cut 14 numbers of wires with equal length by using a Nipper.Then strip out the insulation from the wires by using a Wire Stripper.Solder Wires to the Display Unit:The TFT display has pre-soldered straight header pins to mount it to the breadboard or any other shield. You have two options1. Desolder the header pins from the PCB and then solder the wires to the soldering pads2. Directly solder to the header pinsI prefer the second one, it is much easier and requires less effort and skill.Before soldering apply a small amount of soldering flux to all the header pins. Then tin the header pins by using a small amount of solder on the soldering iron tip. Tinning is required as it makes the soldering process easier and strong bonding between the wire and header pins.Finally, solder the wires to all the header pins as shown in the above picture.3D Printed Enclosure:I have modified the enclosure in Autodesk Fusion 360 by taking reference from a nice model available in Thingiverse and designed by smily77. The dimensions of all the components are measured by a vernier caliper then the same were considered during the design.The enclosure has 3 parts:1. Housing Body2. Back Cover3. Base CoverDownload the STL files from ThingiverseI have used my Creality CR-10 Mini 3D printer and 1.75 mm white PLA filament to print the parts.My settings are:Print Speed: 60 mm/sLayer height: 0.2mmFill Density: 20%Extruder Temperature: 210 deg CBed Temp: 60 deg CInstall the Display:In this step, you have two options1. First Install the Display into the enclosure then solder the wires to the Wemos Board2. Make the wiring between display and Wemos board first, then install them into the enclosure later.I have shown both ways in the above pictures. The pictures themselves are self-explanatory.My personal preference is the second option.Wiring Diagram:The wiring diagram is very straightforward. You have to connect the TFT display module ( ILI9341 ) pins with Wemos pins as per the schematic diagram. The schematic diagram is shown above. You may also follow the following pin mappingTFT Display->Wemos ( ESP8266 )VIN -> 3.3VGND -> GNDCS -> D1RESET -> RSTDC -> D2SDI -> D7SCK - D5LED -> D8SDO -> D6T_CLK -> D5T_CS -> D3T_DIN -> D7T_DO -> D6T_IRQ -> D4Make the Circuit:First, download the schematic diagram, then take a printout. It Is really handy during the soldering and you will save a lot of time also. The most important thing is any mistakes in the connection may damage the display module or Wemos board. During the making of this project,I have fried my display unit touch screen IC due to some mistake in connection.Prepare the Arduino IDE for ESP8266 Board:The ESP8266 module isn't part of the Arduino-IDE, so we have to install it first. You can easily install it by going through the following steps:1. Start Arduino IDE and open the Preferences window.2. Enter https://arduino.esp8266.com/stable/package_esp8266com_index.json into the File>Preferences>Additional Boards Manager URLs field of the Arduino IDE. You can add multiple URLs, separating them with commas.3.Close this window with the OK Button. Open Boards Manager from Tools > Board menu and select the correct ESP8266 board.4. Now you can choose LOLIN(WEMOS) D1 R2 & mini. Set the CPU frequency to 80MHz, Flash Size to "4MB (FS:3MB OTA:~512KB)", and the COM port.Download the Code and Libraries:You can download the Arduino code and supporting libraries from the following links.Arduino Code:https://github.com/ThingPulse/esp8266-weather-station-colorLibraries:1. Mini Grafx by Daniel Eichhorn2. ESP8266 WeatherStation by Daniel Eichhorn3. Json Streaming Parser by Daniel Eichhorn4. ThingPulse XPT2046 Touch by ThingPulse (forked from Paul Stoffregen), if you had previously installed the original XPT2046_Touchscreen then you need to uninstall that one!After downloading the library unzip it and installed it with your Arduino Library Manager inSketch > Include Library > Manage Libraries...Get OpenWeatherMap API Key:The Weather Station real-time data is obtained from the OpenWeatherMap website. So you have to get the OpenWeatherMap API Key.Now you can choose the free plan in the first column. There is no cost to apply for a free plan, which is more than sufficient for our requirements. Only the limitation of using the free plan is that you are limited to 60 calls per minute.Now click on Get " API Key " then create a new account by filling up your credentials.Note down the API key which will be required in our code in the next step.Upload the Software:After setting up Arduino IDE and installing all the libraries we can move to upload the code into the ESP8266 board ( Wemos D1 Mini Pro or any other board )First, you have to unzip the code downloaded in the earlier step and then save it somewhere on your PC or Laptop. Remove the word master from the folder name, the final name shall be " esp8266-weather-station-color "Now open the folder and click on "esp8266-weather-station-color.ino "In one of the tabs, the IDE opened settings.h. Go through the file and adjust the two handfuls of configuration parameters. They are all documented inside the file directly. Everything should be self-explanatory. Most importantly you will need to set the OpenWeatherMap API key you obtained in a previous step.Now you are ready to upload the code, just hit the upload arrow button.Install the CoversAfter mounting the display unit and circuit board, we can move to box up the housing by using the two covers. The enclosure is designed with very tight clearance, so you don't need any glue or screw to hold the covers.Align the cover with the slot in the enclosure and press it all around, you are done. The smaller cover is for the base part and the larger one is for the backside of the display part.TestingIf you are successfully uploaded the code into the ESP8266, you will immediately notice the display on the front page by searching the WiFi Network for connection. After connecting the device to your WiFi router, it will update the time and weather data from the web.Now you will be able to see all the weather information along with all other parameters on the TFT display. You can swap between the different pages by using the stylus or touching with your finger.Note: In the beginning, you will be asked to touch the screen for calibrating the touch screen display.I am super happy with the final outcome of this little gadget. You may gift this little gadget to someone on any occasion.

I was always amazed at these small devices. My dad uses these to log into his work laptop, I couldn't understand how can it generate a code without being connected to any network.I fired up google and tried to search about it, and surprisingly it used a pretty amazing concept. It had a shared key with the server, and then it did some computation on the shared key and current UTC time to get a 6-digit number. So, the remote device just had to be accurate at timekeeping. It uses an algorithm called TOTP (Time based one time password), it's been standardized and there's no point in getting into the details, here's the standard if anyone wants to take a look. You can read this article on freecodecamp.org for a more layman-ish approach to the whole algorithm.First PrototypeComing back, so I decided to implement this using ESP32, because I had a devkit lying around, and the OLED and RTC libraries were solid, and I could use WiFi to get accurate time, which is absolutely need to generate the codes, here's a picture of the first prototype.It worked fine, I used to generate a secret key from here, and then flash the esp32 with the new key and boom, it generated codes I wanted to (It was not as easy as it sounds, I had to spend days putting together a firmware to do it, and it was start of Covid-19 Lock down so I had a lot of free time).Second PrototypeI wanted to take this to next level, make something like those RSA key id devices, but more configurable and not exactly use and throw like those and ESP32 was the right tool for it. So, I designed a PCB for the same. It was a long process, I had to handle my summer internship, finally by October I finished designing it and after getting it reviewed and rerouting again after two weeks, my PCB was ready to be ordered.Final DesignAfter the second prototype I wanted to make it more sleek as the OLED was being used as a external module and it increased the height too much. So, I designed a new board, basically updated the board design by rerouting and optimizing it. You can see both designs and see the improvements.https://www.freecodecamp.org/news/how-time-based-one-time-passwords-work-and-why-you-should-use-them-in-your-app-fdd2b9ed43c3/