hybridfree/eevblog-posts huggingface dataset:
ESD safe material - Page 1
Forum section: electronics / projects

author: tim510
author_rank: Contributor
timestamp: April 26, 2012, 01:38:37 am
content: I need to test some photovoltaic (pv) cells that are on PCBs. I would like to mount these on some type of board so that the pv cells can be angled to test outside. I think what I need is a material that would be esd safe and ideal to mount PCBs on.Any suggestions would be appreciated.Thanks.

author: Monkeh
author_rank: Super Contributor
timestamp: April 26, 2012, 02:05:12 am
content: Uh.. perhaps a sheet of ply?

author: tim510
author_rank: Contributor
timestamp: April 26, 2012, 04:56:17 am
content: I thought of ply. Maybe someone may have experience with some other types of material. Some synthetic materials are cheaper.Thanks.

author: westfw
author_rank: Super Contributor
timestamp: April 26, 2012, 08:17:39 am
content: I saved a goodly amount of pink and green anti-static shipping foam. By the time you get slab a cm or two thick, it starts to get pretty rigid. You can see some sitting under the "tower system" here:http://www.flickr.com/photos/58843278@N00/3866502441/#in/set-72157622049680333I'm not sure where you'd get this if you had to buy it :-(

author: T4P
author_rank: Super Contributor
timestamp: April 26, 2012, 11:39:12 am
content: Quote from: westfw on April 26, 2012, 08:17:39 amBoth RS and Farnell sells them .

author: metalphreak
author_rank: Frequent Contributor
timestamp: April 27, 2012, 10:43:17 am
content: http://au.element14.com/jsp/search/productdetail.jsp?SKU=168784601High density black conductive foam. The kind of stuff you'd normally see DIP IC's pushed into for storage. 5mm thick. I got some in my last order for the heck of it since its a dollar

author: tim510
author_rank: Contributor
timestamp: April 27, 2012, 04:50:32 pm
content: Thanks for the suggestions. I would have never thought of the foam packaging for ICs.

author: nctnico
author_rank: Super Contributor
timestamp: April 27, 2012, 05:23:08 pm
content: Quote from: tim510 on April 26, 2012, 01:38:37 amAlumin(i)um sheet. Easy to cut and drill.
ESD - surface resistivity tester design - Page 1
Forum section: electronics / projects

author: Circuitous
author_rank: Unknown
timestamp: December 13, 2011, 01:44:42 am
content: Has anyone seen anything on building your own surface resistivity tester? I'm primarily looking to verify that various ESD mats are working.

author: IanB
author_rank: Super Contributor
timestamp: December 13, 2011, 05:31:58 am
content: Some of the higher end multimeters like certain Flukes have a conductivity test mode for insulation testing and measuring high resistances above the limits of the normal resistance mode. That would be the easiest way.

author: ejeffrey
author_rank: Super Contributor
timestamp: December 13, 2011, 09:27:41 am
content: You need a way to probe it properly. Poking standard tips into the surface will not work very well. The measured value will be very high due to spreading resistance and depend on the exact contact area. A simple probe would be two disks or rings of a known diameter (say 1 cm) that you push into the ESD mat. You could also use long thin bars that you pushed into the edges of the mat to get a value reading directly in ohnm/square.If the value is too high to measure with your handheld meter you can use an insulation tester or electrometer. If you don't want to pay the $$$ you can DIY. All you need is a 10 V power supply, a resistor (100 kohm or so) and a voltmeter. Measure the voltage drop across the resistor and you know the current. A good FET amplifier for the shunt resistor (like Dave's ucurrent adaptor in nanoamps mode) would work even better here.

author: Circuitous
author_rank: Unknown
timestamp: December 19, 2011, 02:57:42 am
content: Thanks for the idea about using a FET current amplifier.I've been waiting for the chance to buy one of Dave's uCurrent adapters, but they've been out of stock for a while. I've checked the store every day for a couple of weeks now, hoping they'll be available again.
ESD surge protection; ESD IEC 61000-4-2 - Page 1
Forum section: electronics / projects

author: tapasxplore
author_rank: Contributor
timestamp: July 02, 2018, 05:39:52 pm
content: Hello,I am using micro USB socket to charge the battery in one of the device and now we are planning to go for CE certification for which we are doing EMI/EMC test. For the ESD IEC 61000-4-2 (+/- 6 kV contact +/- 8 kV air) test standard. The outer shied of micro USB should be connected to ground. But in one of the reference diagram it is connected to ground via some resistor and TVS diode. (Schematic attached below). Should I connect micro USB outer casing to ground or connect it via some resistor to ground and then employing TVS diode as shown in the schematic. I think using the second technique the ESD pulse would not affect the common ground and will not affect the sensitive IC connected to the common ground.Regards,Tapas

author: wraper
author_rank: Unknown
timestamp: July 02, 2018, 05:46:08 pm
content: Never connect anything between USB connector shield and GND on the PCB unless shield is grounded to the enclosure by conductive gasket or something like that.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 02, 2018, 09:11:53 pm
content: Quote from: wraper on July 02, 2018, 05:46:08 pmAll this. ^^^^In fact, not only that, but also, when grounding the shield, ground it at multiple points. Treat it as an RF shield. Because that's what it is.And by "ground", I mean RF ground. You don't need a galvanic (DC) connection, just the high frequency bypass to circuit ground (or enclosure). If floating the shield, use two or more ceramic chip capacitors, distributed evenly around the connector.Tim
ESD TVS voltage, current and power rating for portable device/mobile phone USB  - Page 1
Forum section: electronics / projects

author: Wilson__
author_rank: Frequent Contributor
timestamp: November 09, 2024, 09:19:29 pm
content: What areappropiate voltage, current and power ratingsforESD TVS(transient overvoltage suppressor) for:a) medium brandb) top brand (like Samsung is top 3 mobile phone)1. portable device interface pins like USB on mobile phone2. human users can walk on carpet (to generate electricity) and air can be low hudmidity (in cold countries with home heater)Application notes generally mention IEC 61000-4-2, level 1 to 4 and the new 4+ (better than 4)Many thanks
ESP 32 MIDI synthesizer with DAC, noise filter, and class AB amp pcb review. - Page 1
Forum section: electronics / projects

author: guyman
author_rank: Newbie
timestamp: August 11, 2025, 02:11:33 am
content: Would you guys mind taking a look at my PCB? This project receives midi input through an optocoupler, processes it on the ESP 32 which send digital audio to the DAC. The DAC output is filtered via a 2nd order Butterworth filter to remove high frequency noise. The filtered audio is then amplified in a class AB amplifier and is output over 3.5mm jack. The audio signal is centered on 2.5V. Any advice on the circuit layout would be appreciated.

author: moffy
author_rank: Super Contributor
timestamp: August 11, 2025, 02:39:14 am
content: Just one comment, to minimise output distortion it would be good to include the AB output buffer within the feedback of the opamp. That would mean a slightly different scheme for setting gain.

author: Terry Bites
author_rank: Super Contributor
timestamp: August 11, 2025, 11:38:18 am
content: Why would we all be using your particular cad package?A set of images in a common format would be a help.Jpg etc?

author: guyman
author_rank: Newbie
timestamp: August 13, 2025, 02:24:35 am
content: my apologies, i forgot to add images. i have now added them
ESP 32 Project - Page 1
Forum section: electronics / projects

author: Farrel
author_rank: Contributor
timestamp: April 23, 2020, 06:12:33 am
content: Hi, currently i'm in project that need indicator (sorta like LED) but in app (i'm using MIT App Inventor 2).normally when the app communicate with the ESP, they use http:IP/command. But how does the ESP send data to the app and how to display it as an indicator (sorta like LED)?Appreciate any help

author: Gixy
author_rank: Regular Contributor
timestamp: April 23, 2020, 06:37:03 am
content: If you have implemented a web server in the ESP, data can be send through the IP/command chains. Lots of exemples on Internet.
ESP Matter - Page 1
Forum section: electronics / projects

author: davorin
author_rank: Unknown
timestamp: September 22, 2023, 08:05:37 am
content: Good morning (o;Are some people here also working Matter/Thread devices?As the official Espressif forum isn't of real help I ask here (o;When I have two matter devices, one sensor and and a heating system which should get actual and set-point temperature...Do I need an external application hooking up to the matter fabric and tell them how to connect?Or is there some mechanism where one device could "see" all available devices and it connect to it?thanks in advancerichard
ESP-WROOM-32 power pins showing connectivity - Page 1
Forum section: electronics / projects

author: Sai teja
author_rank: Regular Contributor
timestamp: March 30, 2018, 01:50:23 pm
content: We designed ESP-WROOM-32 embedded board for vibration alert application. Initially, it was working well. But suddenly it stopped working and the power pins (3V3 and Gnd) pins of ESP-WROOM-32 showing connectivity with the multimeter.What might be the reason for this to happen?Please help me in this regard.

author: Sceadwian
author_rank: Unknown
timestamp: April 02, 2018, 02:11:43 am
content: You've provided no circuit diagram or details about it's actual use the fault could be almost anything.
ESP23 RMII Layout With DP83825I - Page 1
Forum section: electronics / projects

author: nbetham
author_rank: Newbie
timestamp: August 26, 2020, 10:55:31 pm
content: Hi All!I'm trying to add ethernet to an ESP32 with a TI DP83825I PHY. Currently I'm trying to layout this design with a two layer board using the bottom as a ground plane and the top as signal and power. However I'm currently running into an issue where the MAC in the ESP and the PHY aren't communicating properly. The ESP is receiving some of the RX packets from the PHY just fine though some are corrupted (0 length frames). TX on the other hand doesn't work unless I probe the clock line from the MAC to PHY and even then packets rarely make it through from the MAC to the PHY. TI states the RMII lines should be 50 ohm characteristic impedance to minimize reflections and losses.My main questions are: For these short runs between the MAC and the PHY is trace impedance significant? Most rules of thumb I've seen say trace lengths anywhere from 1/10 to 1/100 the wavelength have negligible transmission line effects. The traces in my design are < 4cm in length or 1/150th a wavelength of the 50MHz RMII signal. And are those rules applicable in this case?For reference the attached pic is a snippet of my design showing the RMII interface between the ESP and the PHY. Note, the 0805s in the signal lines are just bridged at the moment, I wanted to play around with adding some extra series termination. But I've also tried a design without the extra series termination and still had the same issues. Any help or pointers would be much appreciated!Thanks

author: bson
author_rank: Unknown
timestamp: August 27, 2020, 08:24:14 pm
content: Almost certainly a clock issue.Do you have a low-capacitance active probe? They're invaluable in situations like this.If it works when loading the clock with a ~10pF passive probe, then this says your source impedance doesn't match the load. Are the pins internally terminated in the PHY? Most likely the problem is overshoot and bounce due to insufficient source impedance; when you add a 10pF load the rise time is reduced and you get less overshoot, and this is enough to make it work. Are you sure it's 50Ω and not 100Ω? 50Ω seems low.Not familiar with the ESP32 MAC, but it's also possible it's a problem with data signalling, and the MAC is suppressing frames with CRC errors.
ESP32-A1S spikes in output - Page 1
Forum section: electronics / projects

author: davorin
author_rank: Unknown
timestamp: February 14, 2025, 12:07:26 pm
content: Good afternoon (o;Has someone seen this behavior on the ESP32-A1S module with the ES8388 DAC?After few minutes I get suddenly spikes in the output which are obviously very good hearable as clicking noise, just like when listening to AM radio with lots of statics.But when I power cycle the module, the spikes are immediately gone for few minutes....

author: tszaboo
author_rank: Super Contributor
timestamp: February 14, 2025, 12:50:59 pm
content: My first guess would be Firmware issue, buffer over or underruns.But if you are sure that's not the case, then perhaps it's power supply related.

author: davorin
author_rank: Unknown
timestamp: February 15, 2025, 08:02:24 am
content: Hmm...might be that a 256kBits/sec mp3 stream is too much for the module....Interestingly the firmware should recognize PSRAM as additional buffer, which it doesn't for the ESP32-A1S module.Though according to specifications it should have 4MByte external PSRAM.
ESP32 and BT "mesh" - Page 1
Forum section: electronics / projects

author: okw
author_rank: Frequent Contributor
timestamp: April 25, 2025, 02:04:30 pm
content: I have questions about suitable ESP32 modules for a project.I want to make a "stationary" unit reading RS232 signals, and a handheld / lanyard unit with a just a "read" button.The stationary unit will connect to a tablet or computer over bluetooth (should support both HID keyboard and SSP), to transfer the RS232 data.The stationary unit will most likely be connected to an AC adapter (or a battery depending on the power consumption).The handheld will be powered by a 18650 or similar.I have already made the project "both in one" which works great, but it would be nice to separate the read button, so the user don't have to carry the whole unit with serial cable connected to the external equipment.I based my project on ESP32-C3, which only supports HID, not SPP. But I want SPP in my next version (so C3 is not an option, right?). Also I'm not sure if I can connect the stationary unit over BT classic (which is needed for SPP, right?) and simultaneously be connected over BLE to the handheld unit to wait for a read command.Any insights here?
ESP32 and CAN 2.0 - Does it really exist? - Page 1
Forum section: electronics / projects

author: skyjumper
author_rank: Regular Contributor
timestamp: February 27, 2019, 06:44:01 am
content: Hi All, I'm trying to build a little board that can stream data from a CAN bus over WiFi and/or BT and ran across the ESP32. The data sheet says it has a CAN 2.0 peripheral, but that's all it says about CAN. There is no label for CAN on the pinout and no indication if this is controller or controller and transceiver.So my question is, does the ESP32 really have a CAN 2.0 controller and, if so, how do I get to it?Thanks!

author: jleg
author_rank: Contributor
timestamp: February 28, 2019, 03:44:05 pm
content: Quote from: skyjumper on February 27, 2019, 06:44:01 amfirst google hit:https://docs.espressif.com/projects/esp-idf/en/latest/api-reference/peripherals/can.html"The CAN controller does not contain a internal transceiver and therefore requires an external transceiver to operate.""The CAN controller’s interface consists of 4 signal lines known as TX, RX, BUS-OFF, and CLKOUT. These four signal lines can be routed through the GPIO Matrix to GPIOs."

author: IDEngineer
author_rank: Super Contributor
timestamp: February 28, 2019, 05:13:58 pm
content: Quote from: jleg on February 28, 2019, 03:44:05 pmI wonder what CLKOUT is for. CAN doesn't have a separate clock signal, not even between the transceiver and PHY chip. TX and RX go into the PHY chip and CAN-H and CAN-L come out. Hmmm....

author: sokoloff
author_rank: Super Contributor
timestamp: February 28, 2019, 05:19:46 pm
content: Quote from: IDEngineer on February 28, 2019, 05:13:58 pmMCP2515 (a common CAN transceiver)has a CLKOUT pin...

author: IDEngineer
author_rank: Super Contributor
timestamp: February 28, 2019, 05:41:29 pm
content: Quote from: sokoloff on February 28, 2019, 05:19:46 pmYes, but it's not related to CAN. It's so you can let the chip optionally generate the clock for your MCU or other hardware. Basically sharing one crystal/oscillator for multiple purposes.Maybe that's what the OP's "CLKOUT" is for too, but it seems odd to be lumped together with the CAN signals. Perhaps his hardware uses an MCP2515-type device and the "designer" didn't understand CAN, so they just brought out every signal just in case.
ESP32-based LCD CANbus gauge: looking for a schematic and layout review - Page 1
Forum section: electronics / projects

author: willman375
author_rank: Newbie
timestamp: August 01, 2021, 11:57:23 pm
content: Schematic, layout, and 3d views located here:https://imgur.com/a/A0Rhh30Background on the project:I own an electric-converted MG midget that currently does NOT have a "fuel" gauge, which is highly problematic for a 100-mile range EV. It uses an Orion 2 BMS that can be queried for battery info (SOC, cell voltages, current, cell temperatures, etc) over CANbus. Instead of doing something simple, I've decided to make a digital gauge using an ESP32,1.28in round IPS LCD utilizing the SPI GC9A01 controller, and the LVGL graphics library. I'll utilize the ESP32 WiFi to host a hotspot and captive-portal web page that lets you configure the gauge. The gauge will be 52mm and install where the original fuel gauge was installed.If this turns out successful, I might consider selling these, hence why I made a proper PCB and enclosure. All design files will be completely open source, however. But the primary focus is simply making a nice gauge for my carRandom notes:LCD flex gets soldered to the back of the PCB, and then bent over and VHB-ed to the PCB. This is the same way many of thedev boards utilizing this LCDdo it.CANbus has software-selectable termination using a SSR.The board can be powered either by the USB-C port (mainly for configuration/debugging) or the JST connector (when installed in car).USB routing is a bit hacky because the board is 2 layer. I reduced board thickness to 1.2mm, and used 30mil width and 6 mil gap which gives a Zdiff of very close to 90 ohms per USB spec. Ground plane is contiguous on bottom beneath the USB lines between IC and port, and directly connects to port and IC ground pins.The enclosure and mounting is TBD/designed. The assembly idea is after putting PCB into enclosure w/ LCD, the back of the board will be potted (or possibly just conformal coated), with just the USB-C and JST connector sticking out the top. Other tall components may have their tops exposed, as potting height is limited by the holes on the side of the USB-C connector.The switch on the front will be pressed by a button that's part of the enclosure's "bezel". Screen will be slightly below center in the enclosure.Important component MPNs NOT shown in schematic (PSU):D6: SS13MHRSGL1: NRS6045T470MMGKVNever had a board reviewed here; I'm greatly looking forward to hearing any feedback on this project/board. Thanks!
ESP32-based Word Clock with 16x16 LED Matrix - Page 1
Forum section: electronics / projects

author: dln-mzny
author_rank: Newbie
timestamp: May 27, 2021, 10:58:25 pm
content: Hi everyone,as part of the finals at my school I'm tasked to do an electronics project.I came up with the idea of building a single-board LED matrix and have it work as a Word Clock. It will look somewhat like this:Each pixel illuminates a letter and together they form a sentence displaying the current time.I came up with a schematic and PCB, both of which are attached as PDFs.Some facts:The matrix is driven by a shift register driving individual columns to +5V while a TLC59116 constant current driver drives individual rows to ground. The driver is configured to sink 30mA per LED, I know you can sink more current if its pulsed, but I'd rather not risk grilling my LEDs if my code fails at first (it will!)The rest of the board includes a CH340G for USB programming the ESP32, a PCF2129 RTC chip (I hope thats better than a DS1307), 5 buttons as controls, and a 74HC4050 buffer as a status indicator driver. I read its best to use a buffer like this to include TX/RX LEDs, as to not load the actual lines too much.I chose the ESP32 as I have a bit of experience of writing code for the ESP8266, and I'm hoping to make use of the ESP32's dual core CPU, and have one core drive the matrix while the other handles timekeeping, button presses, maybe even communicate with a mobile phone over bluetooth.Now, this being my first big project, and the first one that's not a hobby project, I was hoping to pick up some advice from you people, that I hopefully didn't make any blatant mistakes in the design.Also, as you can see I haven't routed a single trace on the PCB, as when it comes to that I'm completely clueless on how to route what, with what width, in the fairly limited space I have on the PCB. Anything I should look out for? Or should I look into doing a major redesign of the PCB?I'm eager to learn, any advice would be greatly appreciated
esp32 custom board - Page 1
Forum section: electronics / projects

author: Boschi
author_rank: Regular Contributor
timestamp: May 11, 2019, 01:00:41 pm
content: this is just a factibility analysis.its a while that i think about doing a custom watch, like picking up the case from a standard analogic watch and fitting the inside with a custom board.for now i was thinking about using a arduino and a few touch buttons in order to do everything, but now i was watching the esp32 and i saw that it has both an integrated rtc and 10 touch pins, this means a lower footprint and a lower current consumption.my main concers would be about the BLE signal getting through the case, the antenna design and also the touch buttons sensitivity (there would be 4 raised pad pressing against the watch glass).4 layers pcb are cheap (50x50 10pcs @1.25€ each) so i would give them a shot, but it would be a 38-40mm circular pcb, and thanks to the small dimension im not sure i can leave the antenna without any trace running over/below it.any consideration? also, keep in mind that i have just a ds1054 as my main tool (for the antenna tuning (?)) and i have never worked with antennas design

author: jram
author_rank: Contributor
timestamp: May 12, 2019, 08:33:57 am
content: It would be worth checking if you can fit your desired code into the ESP32 as some of the bluetooth libraries are huge. As far as the antenna is concerned, there are many types available that could be mounted away from the board.
ESP32 Data Transfer - Page 1
Forum section: electronics / projects

author: Sparky49
author_rank: Regular Contributor
timestamp: October 02, 2018, 04:23:33 pm
content: Hi,I've been doing some very simple experiments with an ESP32 module running an Arduino core recently, as part of a project where I'd like to control the duty cycle of two PWM lines from an android app through a wifi connection. I have some basic skills in C, but very little experience in interfacing with existing code/protocols etc - mostly I've just been writing simple embedded stuff.Whilst I've managed to get the ESP to toggle a GPIO on or off by changing the url through a browser, or by clicking a hyperlink on a server created on the ESP using example code, I don't think that this would be ideal for controlling two separate duty cycles, as you'd need to have a whole host of urls to send data. Is there a more efficient way of sending data to my ESP32 via wifi? I envisage that it would likely take the format of a string, say "A32" for pwm channel A at 32%.I have seen services like Blynk, but would prefer to stay away from such things as they seem to make it too easy - I want to learn about the processes involved, but my inexperience in this field has it seem a bit daunting. Any further advice regarding how to learn how to understand these processes would be appreciated too.Thanks in advance.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: October 02, 2018, 05:00:20 pm
content: Can't use url parameters? Like this:http://device/pwm?dutycycle=45

author: Sparky49
author_rank: Regular Contributor
timestamp: October 02, 2018, 05:02:22 pm
content: That seems so obvious now you mention it.Perhaps that would be best for me to use until I get more familiar with the systems in play. Thanks George, much appreciated.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: October 02, 2018, 05:19:40 pm
content: You're welcome!

author: JustMeHere
author_rank: Frequent Contributor
timestamp: October 05, 2018, 12:43:07 am
content: You want to use a REST style api. The example above is a start.

author: rjp
author_rank: Regular Contributor
timestamp: October 05, 2018, 12:53:29 am
content: their are 3 main options.custom udp or tcp - open a raw socket straight to a custom daemon on some server type machine.this one is good for learning but also means you need recreate alot of wheels.http - usually REST, easy to do, relatively slow and resource heavymqtt - very lightweight and has some nice features like distributed events, eg: you can extend it to other lights without changing the main code.potentially makes things more complicated with maintaining multiple daemons, if you dont like that sort of thing.

author: Sparky49
author_rank: Regular Contributor
timestamp: October 05, 2018, 05:24:43 pm
content: Thanks JustMeHere and rjp, alot of terminology I have never come across but will have fun reading up on!Fwiw I managed to get the method mentioned by George implemented, and just finishing off by fiddling around with some interrupts now.I will definitely have a look at the other methods mentioned though.
ESP32 deep-sleep button debouncing - Page 1
Forum section: electronics / projects

author: cheeseburger
author_rank: Contributor
timestamp: April 01, 2025, 11:10:46 pm
content: I currently have an application using an nrf52840 with Zephyr, it runs a task to run some logic to detect different types of button presses including debouncing of the input. It can do stuff like detect short-press, long-press, double-press and so on. Since the device is battery-operated, power consumption is a key concern.Now I'm considering switching to an ESP32-S3 or similar because it is way cheaper and more powerful than the nRF52840. However, as we all know, ESP32s consume a lot of power during operation, though their deep-sleep mode is quite efficient.Has anyone implemented complex button press detection while leveraging deep-sleep? I’m struggling to find an efficient way to perform reliable button detection in combination with deep-sleep, especially since waking from a pin-change interrupt to executing software takes several hundred milliseconds on the ESP32-S3. Are there any smart tricks to handle this effectively?
ESP32 Development board - Page 1
Forum section: electronics / projects

author: jcrubin
author_rank: Frequent Contributor
timestamp: October 21, 2022, 09:36:07 pm
content: My wife had picked up a new book on ESP32 development that had included information on the purchase of a development board to follow along with. We though it interesting to assemble out own board and add whatever we wanted to with features and improvements that we thought would be cool.SHOPPING LIST----------ESP32 ****NOT FOR USE IN PCB MODULE, IT REQUIRES SPECIFIC ESP32***https://www.amazon.com/dp/B0718T232Z?ref_=cm_sw_r_cp_ud_dp_YBQBGZBZPZ57JCFSNJN1PROTO BOARD -https://www.amazon.com/gp/product/B0814CVQVV/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1PCB Module -https://www.amazon.com/gp/product/B092H9FM3R/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1Electronics Bundle Kit -https://www.amazon.com/gp/product/B01ERP6WL4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1RGYB LED Barhttps://www.amazon.com/gp/product/B07SKVBX2X/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1LCD Display Modulehttps://www.amazon.com/gp/product/B071FGZX8G/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1Female Socket Pinshttps://www.amazon.com/gp/product/B0778TFL39/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1840 piece Wire Jumpershttps://www.amazon.com/gp/product/B081H2JQRV/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1M3 Standoff Kithttps://www.amazon.com/gp/product/B07D7828LC/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1Rotary Encoderhttps://www.amazon.com/gp/product/B07T3672VK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1Motion Detection Sensorhttps://www.amazon.com/gp/product/B07RT7MK7C/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1Temp Pressure Sensorhttps://www.amazon.com/gp/product/B07KYJNFMD/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1Distance Sensorhttps://www.amazon.com/dp/B01JG09DCK?ref_=cm_sw_r_cp_ud_dp_RYJK4XH3QWZY5ZK7ZXHN74HC595N DIPhttps://www.amazon.com/gp/product/B0993RQGQY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1Stepper Motor and Driverhttps://www.amazon.com/dp/B01CP18J4A?ref_=cm_sw_r_cp_ud_dp_QCFMM445C6WE9HT19TKWMicro Servoshttps://www.amazon.com/dp/B07MLR1498?ref_=cm_sw_r_cp_ud_dp_M58J62M3V92CZ1V728Y0

author: bomp
author_rank: Newbie
timestamp: October 22, 2022, 04:32:21 pm
content: Looks like a fun project.What book on the ESP32 do you recommend?K
ESP32: I2S Bus Question - Page 1
Forum section: electronics / projects

author: waymond91
author_rank: Regular Contributor
timestamp: January 13, 2022, 01:35:55 pm
content: Hello all!I have a quick question about I2S: Can I read from a MEMs microphone and write to a speaker on the same I2S bus?I’ve put the two devices on different L/R channels:Its basically a low-range, low-bandwidth walkie talkie: so the device needs to read the microphone data, packetize & transmit it, and then listen for and play any incoming packets.I’m hoping to program this thing using Arduino on an ESP32 breakout board called the “ESP32 TinyPico - Nano.”I have never used I2S before - will this work as expected?The microphone should output on the right channel (via the pullup on pin 2: LR).The amplifier should listen on to the left channel via a resistor divider made from the external pull-up on pin 4 (SD_MODE) and an internal pullup resistor:Quick links to datasheets:ESP32 Board (Schematic) :https://github.com/tinypico/tinypico-hardware/blob/master/TinyPICO%20Nano/TinyPICO%20Nano%20P1%20Schematic.pdfESP32 Board (Product Page):https://www.tinypico.com/tinypico-nanoMEMs Mic:https://invensense.tdk.com/download-pdf/ics-43434-datasheet/Audio Amplifier:https://datasheets.maximintegrated.com/en/ds/MAX98357A-MAX98357B.pdf

author: ve7xen
author_rank: Super Contributor
timestamp: January 13, 2022, 10:14:35 pm
content: The I2S bus can be used with multiple devices, but generally not on different channels using the same data line. Usually the 2 or 3 clocks are shared, but a separate data line is used for each pair of channels, especially if one is in and one is out. With your channel-selectable devices it might be theoretically possible to multiplex input and output on the same line, by switching the direction on the microcontroller, but most I2S peripherals I have seen use separate pins for input and output so you'd need additional logic for that. The channel selection pins are generally used for multiple devices in the same direction.I'm not too familiar with ESP32, but it does claim to have two I2S peripherals and support full duplex operation, so this should work if you use a separate data line for the mic and amp. There's a full duplex example as wellhttps://github.com/espressif/esp-idf/tree/ebf7e811b12e3c1e347340e5b9ec014e9c6319ba/examples/peripherals/i2s/i2s_es8311
ESP32 & Lora Node 2uA IQ no deep sleep! - Page 1
Forum section: electronics / projects

author: soubitos
author_rank: Frequent Contributor
timestamp: January 16, 2021, 09:54:08 am
content: This is the board for an ESP32 & RFM95 sensor nodeIt is using a TPL5111 to turn on every 30/60min (switch selectable).When off, it consumes less than 2uA.Has an RTC with onboard CR1220 backup battery & an I2C temp/humidity sensor (the idea being to monitor board temperature and humidity inside the enclosure as a precaution in case something goes wrong with the otherwise waterproof enclosure)...Using spring loaded terminals to allow connection to UART, I2C, VP/VN, SPI, 4x Analog Inputs & 4x GPIOBattery charger is sitting on top and left side connecting to the board with XT30 connectors which are very sturdy.This allows using Lead Acid chargers or Li-Ion chargers designed for this but can also use a battery directly connected to the board allowing operation for months before it needs recharging (depending on capacity and self discharge of course).There are voltage dividers on the 4 analog inputs with a fixed 10k ground side resistor and footprint for 1206 or TH resistors installed by the end user to adjust for various input voltages.Timer has a manual ON button and there are onboard reset & flash buttons.This is sort of a development kit with easy connections to it and once firmware is developed it can be DIN rail mounted and wired as the end productI plan launching a GroupGets campaign once i have the first small batch made and tested.
ESP32 minimal board with ethernet (LAN8720) - Page 1
Forum section: electronics / projects

author: nuclearcat
author_rank: Unknown
timestamp: July 08, 2022, 11:06:20 pm
content: Just finished testing minimal board (that i will use as ESP-NOW to Ethernet gateway and base for future projects) and published under opensource license.Minimal Arduino project included, should be compatible with SDK examples as well.Contains all info(gerbers, pos, bom) required to order on JLCPCB.Comments are welcome.https://github.com/nuclearcat/ESP32ETH

author: nuclearcat
author_rank: Unknown
timestamp: July 09, 2022, 05:54:48 pm
content: Quote from: evb149 on July 09, 2022, 01:36:05 pmI didnt stress-tested much, except just various icmp test-patterns (usually it is enough to find issues on low level stack), including flood ping. Pulled about 30GB both direction without any error, which means i am withing specs for BER.Can't recall exactly, but on other project i had issues with way less pleasant routing for other PHY, maybe IP101?. This board likely wont pass EMI tests as it is 2 layer and because of that routing is more painful if board is more populated than this minimal design. But anyway, it is still 100Mbit, so it is very forgivingMain trick with ESP32 is how PHY can be clocked, as there is several configurations possible.1)We clock PHY by crystal, then we feed ESP32 to GPIO0 which i consider not really great by multiple reasons (BOM, GPIO0 need to be routed for programming pin so impedance will suffer, etc etc)2)Use GPIO16, i was getting out of phase issues sometimes.3)GPIO17 as i did, phase issues seems corrected by inverted clock, downside that this pin might be used by PSRAM in some modules.

author: globoy
author_rank: Frequent Contributor
timestamp: July 10, 2022, 04:47:22 pm
content: Thanks for sharing your design! Nice to be able to use GPIO17 as PHY clock out without having to invert it externally. Bummer it isn't available for modules with PSRAM.I have a couple of quick questions.1. There doesn't appear to be a capacitor to ground (e.g. 1 uF) on EN. Is there any risk that the ESP32 will enter serial boot more on power-up since EN and GPIO0 are going high at the same time?2. In general how are you finding availability of PHY chips? I'm creating a design and when I started LAN8720A parts were unavailable but I did find availability of IP101 (designed into my current layout).

author: nuclearcat
author_rank: Unknown
timestamp: July 10, 2022, 07:40:10 pm
content: Quote from: globoy on July 10, 2022, 04:47:22 pm1. Never seen that yet, i have quite many boards done such way. I wonder if anyone else faced such issue? Maybe it is good to make "ESP32 minimal circuit checklist" then, with such notes.2. I can say "never disappeared for long time", but you know, it's all unpredictable these days.

author: danilo_prof
author_rank: Newbie
timestamp: December 04, 2022, 09:02:54 pm
content: Hi, could you please explain how to import your project in Easyeda?tks
ESP32 MQTT+HA - Page 1
Forum section: electronics / projects

author: Rikitaki
author_rank: Newbie
timestamp: September 16, 2025, 07:57:26 am
content: Created devices based on ESP32, raised MQTT server and Home Assistant serverMeasures temperature, humidity and pressure. Sensor DHT-22, BMP-280, TMP117AIDRVR. I want to add liquid pressure measurement and recording on microSD, or is this not necessary?

author: paulca
author_rank: Super Contributor
timestamp: September 16, 2025, 10:55:16 am
content: Personally I use a python script to relay the MQTT data to InfluxDB and then point Grafana at it. Makes Home Assistant look like a toy.

author: Rikitaki
author_rank: Newbie
timestamp: September 16, 2025, 11:06:44 am
content: Thank you very much, I didn't even know about this in my region. I went to study everything, the information is just gold!)

author: paulca
author_rank: Super Contributor
timestamp: September 16, 2025, 11:22:47 am
content: Quote from: Rikitaki on September 16, 2025, 11:06:44 amEnjoy. A word from experience... set your retention policies early. Data will grow and grow and grow and as Influx is a "memory mapped" DB, it will eat all the memory on your server.I keep the default to 30 days at nano second resolution. Then I use "continuous queries" to reduce that data down to a sample rate of 5 minutes and store for 2 years.Other helpful hints.MQTT Explorer - an easy MQTT interface for debugging/poking.Zigbee2MQTT - with a zigbee dongle gives you a solid MQTT intergration layer, without HA. Supports most common devices.MQTT as you may have noticed does not support timestamping of messages. So you MUST timestamp data yourself to make it useful. Personally I do this "server side" as a base validation that all data has a timestamp and if any doesn't it just gets "now".Also, be wary of using MQTT in anger on MCUs. Usually the protocol is full form JSON. Receiving and parsing buffers of JSON on an MCU is actually quite intensive. On a busy topic or group topic you can very easily overflow kilo bytes of buffers. Most "end devices" I have are send only. "Logic" happens server side and so any device that recieves just receives a short, simple action message.I used an STM32F411 to receive MQTT messages from an ESP32 in AT command mode. I subscribed to the main topics as I would server side. Then I filtered out the messages I didn't want. Unfortunately the STM32 could not keep up. In the end I made a new topic with just the data it wanted in short, abreivated form and subscribed to that topic only.

author: Rikitaki
author_rank: Newbie
timestamp: September 17, 2025, 03:58:05 am
content: Yes, Grafana is certainly good, but when I try to download the installer from my region, I get the following error: "This region is not supported." This is completely against the AGPLv3 license, so thanks for the information.
ESP32 Numitron clock - Page 1
Forum section: electronics / projects

author: nexus
author_rank: Regular Contributor
timestamp: November 30, 2019, 07:18:08 pm
content: Hi all,Being new to the forum, I thought I'd share my most recent project which is my one of my first serious attempts at embedded design.It is a clock using RCA DR2000 "numitron" incandescent display tubes, controlled by constant current LED drivers and all run by an ESP32-WROOM module. It also currently has the capability for setting time over Bluetooth and I'm working on getting the WiFi up to automatically sync the on-board temperature compensated RTC with NTP.Not too shabby for a mechanical engineer right?https://neonkev.com/2019/11/30/esp32-numitron-clock/

author: nexus
author_rank: Regular Contributor
timestamp: November 30, 2019, 07:20:11 pm
content: Thought I'd put a picture up here as well.
Circuit Design: HTU21D and ESP32-POE-ISO I2C Long distance Issues - Page 1
Forum section: electronics / projects

author: virtapp
author_rank: Contributor
timestamp: July 28, 2020, 06:10:06 pm
content: Hi, i'm trying to design an interface to read a 10x I2C HTU21D from this sensor that is produced by a local factory here in France (schematics below) temperature and humidity sensor and send data to an mqtt broker using an ESP32-POE-ISO from olimex.This is the sensor side sch:In the MCU side i'm using the same PCA9306 in order to use 5V and go "far" (30m) from the main MCU PCB using CAT5E cable and RJ45 connectors (The I2C cables used are White-Green/Green for SDA and White-Blue/Blue for SCL).The MCU circuit is very simple, basically there are 10 GPIO's used to enable the MCU side PCA9306 and "select" the right sensor to read.The cable has a capacitance of 56pf/m, so30 metersare 1680pf in total, higher than the maximum I2C limit of 400pf...i know that and i can't change nothing as project specs.The I2C bus speed is lowered to 100khz and there are external pull-up resistor of 10k on I2C bus (ESP32 side) and 330ohm pull-up resistors on the PCA9306 bus side in order to counteract the wild cable capacitance of the bus.Here is the schematic of the MCU Side (a part of the ESP32 MCU those components are repeated 10 times):For some additional informations below there is the scope trace of the SCL bus signal measured at 30m away from the MCU pcb (SCL - CH1): As you can see, the clock waveform is really sharpen - In this scenario, data reading works but it's unstable: like 10 measurements wrong every 100I've already tried to lower speed to 10khz, add precise timings to the Arduino sketch, etc...in any case, in my lab environment this works (with some problems, like 10 measurements wrong every 100) but when i go out of my lab, like in a datacenter or office, many times from all 10 sensors only one works and really i-don't-know-why!Maybe is the ESP32-POE-ISO POE power extraction that is poorly designed?Maybe is the ESP32 I2C interfaces that is a poor interface?Maybe i have to add something that will filter noise on the I2C bus?I have to use those sensor in industrial environments and offices...and i need to get them work: in the past there was an old hardware and they works without any problem...what i'm missing? what i have to modify/add to the schematic?Many thanks in advance!
ESP32 Project Board - Page 1
Forum section: electronics / projects

author: Bootalito
author_rank: Unknown
timestamp: May 11, 2018, 02:48:28 am
content: I could not find an ESP32 board that suited my needs as a microcontroller that I could easily incorporate into different larger project designs, so I designed my own.Requirements:1. Full size female USB-B ("printer" cable) to allow a more natural cable connection common to the back of benchtop equipment projects2. Antennae connector to allow mounting a proper external antennae to a project enclosure3. DC-DC buck converter instead of linear regulator to allow larger input voltage (7-28V) ranges and less heat waste4. Gigantic (well.. only 6.3V so relatively small) 1000uF capacitor to prevent voltage drops when WiFi takes a gulp of power.5. Decent USB protection (ESD and PTC fuse)6. Bread board...usable. It spans the width of two columns7. Through hole design to allow for integration into a larger project by using up less space on the main project PCB by going vertical.8. Sized to allow a 1 x 2 PCB layout under 100mm x 100mm, thus enableing to buy 10 boards for $2, but getting 20!EasyEDA.com Project Page

author: LukeW
author_rank: Frequent Contributor
timestamp: May 11, 2018, 11:22:12 am
content: It looks OK, well done."Antennae connector to allow mounting a proper external antennae to a project enclosure"I'm not sure what this means. There's no antenna connector on your board - and the ESP32-WROVER module has an antenna (and U.FL connector on board), so you don't have to implement the RF stuff yourself on the carrier board.You'll need to solder the buck regulator module very carefully and make sure that the wires don't protrude through to the top of the PCB, otherwise you won't be able to get the ESP32 module flat.If it was me I would probably consider adding a LiPo battery and charger/regulator hardware, because this sort of portable battery power plus wireless connectivity is a very common use case.You probably need to remove the groundplane around the antenna on the ESP32 module, for best results.

author: Bootalito
author_rank: Unknown
timestamp: May 11, 2018, 12:02:00 pm
content: Quote from: LukeW on May 11, 2018, 11:22:12 amThanks for your feedback. The wrover module has an antenna connector in the upper right corner. I will be cutting the PCB Trace. If I could easily source an esp32-wroom-32u I would use this instead as it lacks the PCB Trace antenna.The buck converter module I solder to the bottom of the board without headers. I blob some solder onto the PCB and all four corners then push the module into the blobs and add solder through the holes on the top of the module. Everything reflows together, and it lowers the height requirement without headers.
ESP32 RF antenna connctor & filter network values - Page 1
Forum section: electronics / projects

author: suku
author_rank: Contributor
timestamp: October 11, 2022, 01:04:22 pm
content: Hi,I am designing custom PCB with ESP32-S3 onboard and I wish to include RF connector for external antenna, similar to how it is done on esp32-s3-wroom-1u.https://hu.mouser.com/ProductDetail/Espressif-Systems/ESP32-S3-WROOM-1U-N8R2?qs=Li%252BoUPsLEnvv7kyEkzf6%252Bw%3D%3DMy problem is that I could not find information about the required PI filter thet is iplemented in the RF transmission line of the wroom module. What are the Capacitor and Inductor values for this RF network?I checked the Espressif design guied but it was not very helpful in regards to RF.https://www.espressif.com/sites/default/files/documentation/esp32-s3_hardware_design_guidelines_en.pdfIf you guys have any tips it would be very helpful.Thank you!

author: suku
author_rank: Contributor
timestamp: October 11, 2022, 01:10:36 pm
content: I removed the shielding off of the wroom module, there is clearly and inductor and two capacitors present in the RF line, but I have no means of measuring their value...

author: Robotec
author_rank: Contributor
timestamp: October 11, 2022, 03:00:29 pm
content: Values of the Pi filter are not shown because they are dependent of the PCB and (depending of the case) antenna, you have to calculate them, if you don't know how, you should be using the module instead.

author: suku
author_rank: Contributor
timestamp: October 13, 2022, 09:18:58 am
content: Calculated the component values based on the 35+10j Ohm impedance of the LNA in of the ESP32 and the 50 ohm antenna connector but I wanted to compare the values with a reference design...Any other ides?
ESP32 suggestions - Page 1
Forum section: electronics / projects

author: Sceadwian
author_rank: Unknown
timestamp: July 29, 2017, 04:08:33 am
content: I picked up an ESP32 devkitC which uses the wroom32 module. Just kind of threw it in my Amazon cart for the hell of it cause it was cheap and I wanted to play. I was a little surprised to see the analog specs were so good and was thinking about playing around with it a little trying to make a miniscope or what not just for the experience and to get used to the ESP32.Any suggestions from folks out there? I'd want to interface a mic and maybe some LV analog signal input (maybe aim for 20-30V)Especially nice would be any recommendations on protection as basic ESD protection would be required and I'm not used to that as I'm a hobbyist though I should have most everything in a bin somewhereI especially liked the video done on EEVblog Youtube channelat about the 2:50 mark the transistors back to back as a zener shunt. Thinking that might make a nice basic protection for a probe line that will never be used for much off a bench? I'm just looking for basic I/O protection.