IoT Community - PCBWay

Hey everyone, how are you doing!So this is the PALPi V4 which is a DIY Retro Game Console powered by a Raspberry Pi Zero W.The IDEA here was to make a portable handheld gaming console that can run RETRO Games like Contra, Pokemon, Super Mario ETC.For Display, I've used a 4 inch Car Monitor Display which is controlled by Composit PAL output.As for the emulation OS, I used RECALBOX as it comes with many preinstalled games.In this article, I'm gonna show you guys the whole built process for this Retro Game Console.MATERIALSFollowing are the things I used in this built-Custom PCB (which was provided by PCBWAY)IP5306 IC10uf 1206 Package Capacitor x82R 0805 Package x11K 0603 Package x210uH Inductor x1SMD Button x1Indicator LEDs x4THT USB Micro Port x1Li-ion Cells 3.7V 2600mahFemale Header pins Con40 x1 (or use two CON20 Pin)Toggle switch x13Raspberry Pi Model 3B+4 inch PAL Display (salvaged from CAR MONITOR)3D Printed BodyDC Barrel Jack5V Barrel Adaptor (for charging the Li-ion cell)Previous EditionPreviously, I made the PALPi V1 which had the same internal spec as this console but it was thick and uncomfortable to hold.The PALPi Lite is an improved version that is now slimmer than the original V1 and is comfortable to hold.Getting startedI started by first designing a slim box-shaped body in fusion360 along with a basic PCB Shape as a reference.After finalizing the design, I exported the PCB's DWG file so I could import it into my PCB Suite to make the outline for the PCB and place the switch in its assigned place.RECALBOXI used RECALBOX OS to run this setupWhy Recalbox OS, why not Retro Pi or other OS?well, the answer here is simple, recalbox is an easy-to-use OS that comes with a lot of Free games pre-installed.Also, it's small and can run on low spec raspberry pi systems.like in my case, I'm using a Rpi Model 3B+ which has 1GB ram.it's not exactly a powerhouse but it can handle a few retro games without breaking a sweat.Installing it is also very easyDownload the Raspberry Pi imager.Select the right OS for your device, which would be RecalBoxselect your system which is Rpi Model 3BRaspberry pi imager will do your work of downloading and installing the RecalBox on the memory card.After installing the RecalBox os, you need to plug your Raspberry pi setup with a Keyboard as the first boot always requires a keyboard.After booting the whole setup, the RecalBox works like a normal emulator.PCB DesignOne of the hurdles during the designing process was how to power Raspberry Pi and Screen together with a 3.7V Source.For that, I used a Power management IC which was IP5306.It's a boost converter IC with a bunch of features that includes Low and high cut of the cell during overcharge and over-discharge along with a battery fuel indicator.It can output 5V 2A which is enough for our setup.I took its minimal setup from its datasheet and prepared a board that has switches along with the power management ic setup that boosts the Li-ion cell to power the Raspberry pi and display.After finalizing the schematic, I converted the schematic into PCB File and started the layout by first placing the switches in their place by using the earlier PCB Outline as a reference.PCBWAYI used PCBWAY PCB Service for this project. I first uploaded the Gerber file of this project on PCBWAY's quote page.I choose yellow soldermask with white silkscreen, there was no special reason for choosing yellow soldermask, I just wanted to see the yellow PCB.I received the PCBs in a week and the PCB quality was pretty great, This PCB is small and I like how the quality of these PCBs was not compromised because of quantity or size.PCBWAY, you guys rock.Check out PCBWAY service for great PCB service at less cost!ASSEMBLYThe Assembly process of the Board includes mainly three stepsSolder paste dispensing processPick & Place processhotplate reflowTestingAdding Through-hole componenetsSolder Paste Dispensing ProcessNow the first step is to add solder paste to each components pad one by one.To Apply solder paste, I'm using a Solderpaste Dispensing Needle with a Wide syringe, and the solder paste I'm using is a regular solder paste consisting of 63% Tin 37% Lead.Pick & Place ProcessAfter applying Solderpaste we move on to the next step which is to add componenets to their assigned location.I used an ESD Tweezer to place each component in its place.Hotplate Reflow Soldering ProcessAfter the "Pick & Place Process", I carefully lifted the whole circuit board and place it on my DIY SMT Hotplate.the hotplate heats the PCB from below up to the solder paste melting temp, as soon as the PCB reaches that temp, solder paste melts and all the components get soldered to their pads, we lift the PCB and then place it on a cooler surface for a little bit, to cool down the heat of PCB.TESTING THE BOARDAfter reflow, the PCB is partially completed. we first need to test whether the IP5306 setup is working or not.To check that I added wires to the INPUT and battery side, I then connected the input side with a USB micro breakout and battery side with a 3.7V Li-ion cell on a breadboard.we then turn ON the IP5306 setup by pressing the SMD button on PCB, doing this will kickstart the circuit, and the LED fuel gauge will display the battery percentage.we then measure the voltage across the output of the IP5306 setup which should be 5V.At last, we connect a 5V 2A Charger via USB micro port (this is for charging the battery), Indicator LEDs will start to blink in a sequence that shows how much battery has been charged.After checking the above points, our circuit is working and now we can move on to the next step which is to add the remaining THT Componenets.ADDING THT COMPONENTSTHT componenets include 20 Pin header pin connector x 2 and 13 tactile switches.First BootBefore moving onto the main assembly, we first need to boot the Rpi for the first time.At this moment, it doesn't have the PAL port enabled or GPIO buttons enabled.To enable them, we first connect the Pi with an HDMI cable and a keyboard along with a 5V 2A stable power source (smartphone adaptor).We boot up the Recalbox and head over to network settings for enabling the WIFI.Editing Part of Config fileOpen Win SCP on your computer, enter the raspberry pi IP Address on it, the user name will be root, and the password for the pi is recalboxroot.go to recalbox>share>system>recalbox.confFor Enabling GPIO Buttons, we only need to change two things in the below section.set controller.gpio.enabled = 1 (It was 0 before) and change controller.gpio.args.map=1, 2 to controller.gpio.args.map=1 (2 is second player controlls)Just change your default setting according to mine, then reboot the whole setup, and BANG, our Recalbox setup will work with buttons.Also, this is the GPIO Map for the buttons. The switch connects each GPIO with GND and that's how the RPI registers the button Tap.Main AssemblyThe main assembly includes adding the circuit board to the 3D Printed body first.then we add the PAL Output of raspberry pi to the main circuit and place the Pi on the circuit board.then we add the screen to the main body and connect its PAL port to the PAL port of raspberry pi, VCC to VCC, and GND to GND.At last, we add hot glue to hold the screen in its place.I then connected an external tactile switch in parallel to the SMD button, this tactile switch is for turning ON or OFF the game console's main power source. I solder the tactile switch on a perf board.then we add Li-ion cell to the battery side of the circuit.FINAL ASSEMBLYTo complete this setup, I added a barrel dc jack to the input side so I could charge this device with a 5V Charger.I used hot glue to hold the barrel jack and Li-ion Cell in their place.Then I glued the Tactile switch to one side of the 3D Printed body.At last, I added the bottom lid to the body with four M2 Screws and our Retro Game console is ready to rock and roll.RESULTHere's the result of this built, a complete handheld gaming console that can run pretty much any old game, from PS1 to the atari game console.What about sound?This console doesn't have a speaker setup built-in that outputs audio BUT, we are using Raspberry Pi Zero W which has BT and WIFI onboard which means we can connect any BT Speaker with it and play games in their original audio.To do that, we go to Setting menu > Bt controller and add a new Bt device.pair it up and the Bt system will get active.As for the sound, I'm using my previously made Jack O lantern Bt speaker that you can check out from here.ADDING GAMES ON ITthis is an Opensource retro game emulator, which means we can add any old game from any game system and run them on this setup!we first need to download the custom ROM of any game you want to play on this game console. For example, I downloaded pokemon emerald. then we first need to connect the Recalbox to our WIFI router.We open WinSCP and add our Recalbox IP Address on it along with the user name- root, and the password for the pi is recalboxroot.go to this menu recalbox>share>rom, it contains all the emulator's folder which contains games ROM, I wanted to add pokemon Emeral in it which runs on Gameboy advance so I had to copy-paste its ROM file in the GBA folder.now reboot your raspberry pi setup and open the GBA Emulator menu, and you will see the newly added game.CONCLUSIONThis setup works and it's 100% Practical in the real world. I played more than 10 hours on this thing in a couple of days.One issue that I found out was the battery capacity was not enough so I added one more 2600mAh Cell in parallel with the existing Cell. This increased its backup time.Also, Raspberry Pi Zero, in general, is not powerful enough to run PS1 games which is a bummer, one option is to overclock the CPU and add a heatsink on it to counter the heating problem.A more permanent solution would be to change it with New Raspberry Pi Zero W2 or get a Raspberry Pi 4 with more RAM.Originally I wanted to go with compute module but because of its unavailability, I was unable to get one.This is it for today folks, thanks PCBWAY for supporting this project!Check out PCBWAY for getting great PCB service at less cost.And I'll be back with a new project soon!Peace

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.