Questions tagged [esp32]

A cheap and low-power microcontroller family using Tensilica Xtensa LX6 CPU cores with integrated WiFi and dual-mode bluetooth.

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2answers
12k views

How to choose alternate I2C pins on ESP32?

I'm a begginer with Arduino and this may be a basic question but I'm facing an issue. I'm using a HTU21D sensor with an ESP32. This sensor use I2C communication. Inside the Arduino library, there is ...
3
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2answers
8k views

Is there alternative to arduino IDE program ESP8266 and ESP32 with arduino toolchain? [closed]

I use ESP8266 and ESP32 with arduino toolchain rather than pure arduino hardware. Arduino IDE is standard and proven but what are the other IDE and advantage/disadvantage ?
3
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1answer
96 views

Why do ESP boards break out the SPI flash pins?

I have an ESP32 development board and a NodeMCU board here. Both breaking out the pins for the SPI flash of the ESP. These pins are mentioned in standard pinout descriptions as must/should not connect....
3
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1answer
5k views

ESP32 AP max connections: 4 or 10?

I am using the SoftAP feature of the ESP to create a central node, and connecting five or six clients in the final application. However, I don't know if i can connect that many clients. One of the ...
2
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3answers
2k views

Calling I2C functions inside an ISR

I have an Adafruit 2.8" cap touch display, which has an interrupt pin (IRQ). I tried to use this with my Arduino Nano, but encountered a problem: When trying to get the touched point from the display ...
2
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1answer
811 views

Using c_str() on String for IPAddress with NTPClient provides wrong values

Libraries NTPClient Board Olimex ESP32-POE board Behaviour I have written a code that connects the board to a local NTP Server (which is an embedded board). I tried assigning the IP Address of ...
2
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1answer
6k views

How do I set a 25 kHz PWM signal on an ESP-WROOM-32?

I want to control a single pin of an ESP-WROOM-32 to have a 25 kHz PWM signal. How do I do that in Arduino Studio? I compiled a "hello world" program for such a device successfully in Arduino Studio, ...
2
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1answer
86 views

ESP32 open “captive portal” on connected

I am using the default example SimpleWiFiServer that comes as an example from the ESP32: #include <WiFi.h> #include <WiFiClient.h> #include <WiFiAP.h> #define LED_BUILTIN 2 // Set ...
2
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3answers
1k views

ESP32 CAM failed to get frame in time

So I think the title says it all. I recently purchased an ESP32 CAM in India for a pretty cheap price. It looks like an AI Thinker but doesn’t have the tag on the chip itself. Nonetheless, to get it ...
2
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1answer
43 views

Need help: Cast from 'char*' to 'uint8_t {aka unsigned char}' loses precision [-fpermissive]

I'm trying to convert the string that I receive from the Websocket to uint8_t that I can copy to the data bytes of CAN protocol frame. I'm using an ESP32 chip and programming it on an Arduino IDE. The ...
2
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1answer
2k views

What is the tool to send file to SPIFSS on ESP8266/32?

Is there good tools (IDE, CLI or IDE addon) to send file via USB port to SPIFSS internal espressif ESP hardware SoC ?
2
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1answer
2k views

How to receive and process a long string sent over serial?

I want to receive about 5kb of data in Base64 format. The following code does not work. Only a few characters are received, sometimes CPU crashes. String content = ""; char character; while (Serial....
2
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2answers
78 views

ESP32: How to run two independent PID controllers, one per core?

I want to control 2 independent processes with 2 PID controllers. Is it possible to run each controller on a separate core? I'm using this PID library. According to its documentation, the PID::Compute(...
2
votes
1answer
64 views

EEPROM: managing address mapping between firmware versions

Is there a common way to handle changes in the mapping between eeprom addresses and variables between firmware versions? It's not about the eeprom memory to survive the update, but to be(come) ...
2
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2answers
207 views

Connecting to MQTT causes DHT11 Sensor to stop working?

I have a project I am working on, based on an ESP32 from NodeMCU. I have a bunch of sensors connected to said ESP32 - they all work and the code itself "works" with a minor quirk. The issue in ...
2
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2answers
986 views

Esp32 Https Problem

I am working on a project in which i have to send GET request to my Company's Https server. I have successfully sent the GET request using NodeMCU v 1.0 (ESP 12E). The NodeMCU 1.0 (ESP 12E) Arduino ...
2
votes
2answers
4k views

Duplicate libraries while compiling for ESP32 in the Arduino IDE

I have just added the ESP32 toolchain to the Arduino IDE (v1.8.0) on Windows 10. To get the IDE to allow me to select ESP32 chips I had to place the Espressif folder in "D:\Program Files(x86)\Arduino\...
2
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0answers
32 views

Get deceleration (negative acceleration when apply brake force)

I want to build a device to measure deceleration force when a car brakes. I am using a MPU6050 for get data and I read from it acceleration on X,Y,Z axes in m/s2 and also it gives me gyro in degrees/...
2
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4answers
3k views

Convert String to IPAddress

How can i convert a String to IPAddress on arduino / esp ? etc. "192.168.1.2" -> IPAddress(192, 168, 1, 2) Tried this void setup() { Serial.begin(115200); IPAddress apip; const char *...
2
votes
1answer
76 views

GPS Module don't provide full data

I connected my gps module (NEO-6M) with esp32doit-devkit-v1 board. The module provided data but many data are missing. My pin configuration: GPS ------- ESP32 VCC ------- 3v3 GND ------- GND TX -...
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0answers
3k views

ESP32 IR remote

my board is a firebeetle esp32 that I am using as an IR remote. After using the Ken Shirrif IRremote library for about 6 months successfully, then the time came to change a few things on the web ...
2
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0answers
232 views

Clock cycle count count for the same command is not equal in ESP32

I am using ESP32 Pico Kit with Arduino Ide. I want to measure operation cycle for a few commands. The code is so simple as below: void setup() { Serial.begin(9600); } void loop() { unsigned ...
2
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1answer
633 views

WindowsError(31, 'A device attached to the system is not functioning.') in arduino

Having board esp32 devkit v1, to get started with arduino ide (installed recommended boards for esp32) I marked board asDOIT ESP32 DEVKIT V1 (as no other options as like ESP32 DEVKIT V1 ) so upload ...
2
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0answers
280 views

Reading data from SPI on ESP32-WROOM-32

I'm newbie with Arduino and need to do a short task: read data from SPI (sent by another microcontroller) and send to WiFi (by ESP32-WROOM-32). I can't understand how to initialize and read data from ...
2
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0answers
647 views

HTTPS POST method fails in esp32

I was trying to connect with server but, I was unable to post the data. I have added the SSL key to connect with server that is happening but HTTPS POST is not. I tried the same method with http, I am ...
2
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0answers
715 views

LED strip with 12v power connected to ESP32

I'm looking at controlling a ws2811 strip and I have seen mention that you should share the same ground between the strip and the controller, which does make sense. I do not currently have a proper ...
2
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0answers
555 views

NPN transistors level shifter [closed]

I'm going to use this for Arduino Pro Mini (5v version) to communicate with ESP32 via UART so I need level shifting. I found this circuit which uses NPN transistor and I'm also going to use it. This ...
2
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0answers
579 views

Use ESP32 as a secure socket

I have a board without network connection, then I bought an SP-WROOM-32 dev kit because it has network connection ability. Is there any way that I use esp32 as a secure socket (just like calling ...
2
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0answers
6k views

How do I interpret the esp8266 “boot mode” message?

Everytime the chips resets, we get the reason and the next boot mode. ets Jan 8 2013,rst cause:XXX, boot mode:(YYY,ZZZ) For XXX we can check the meaning here. For YYY and ZZZ I am not sure but I ...
2
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0answers
8k views

ESP32 in Arduino-IDE with FS.h and SPIFFS

I'm working on a webserver on ESP32 in Arduino IDE and would like to load an html-file. Tried to use SPIFFS.open from the library FS.h from github. Errormessage says SPIFFS was not declared in this ...
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2answers
31 views

Is WiFi traffic encrypted on ESP32?

I am using the ESP32 in soft access point mode. In other words I specify my wifi username and password on the ESP32 and I am able to connect to it from my phone. So I am not using any router or ...
1
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2answers
57 views

Two sensors using I2C

We have two sensor one of them(MPU6050-gyro) is communicating using I2C, the other is via SPI(SD card reader). Now, we need an additional component as a sensor that the barometer which communicates ...
1
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2answers
263 views

Two floating point values do not get added and printed on ESP-WROOM-32

I have a Olimex ESP32-PoE board which has a ESP-WROOM-32. I just found out a strange behaviour for printing floating point numbers on the board. Sketch void setup() { // put your setup code here,...
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2answers
103 views

Merge two Arduino projects (change build process)

I'm working on a big software project consisting of several Arduino sketches. I have one Arduino project providing general functionality, such as TCP/IP communication, parsing queries, handling errors,...
1
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1answer
2k views

How to detect water presence with only 2 wires

I don't know if this question belong here or on electronics SE. A manufacturer just sent me a personalize device which include an ESP-32 and a Water Sensor. My problem is that I don't know how to ...
1
vote
1answer
7k views

How do you convert a formatted print statement into a string variable?

I'm using the following routine to print the current time on the com port. I would like to capture this as a string so I can display it using ePaper. void printLocalTime() { time_t rawtime; ...
1
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2answers
123 views

Is there an alternative to strtok_r in extracting words from char?

The task, in char, I get some data that I have to parse into parts. In this case, I use strtok_r, which finds identifiers like "=", " ", "&" Code: char payload[70] = "GET /wifi?ssid=MyWiFi&...
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1answer
3k views

Synching local clock usign NTP to milliseconds

I am interested in getting a local clock on an ESP32 module synch to a network clock using NTP. I am able to read data and time here. But I am interested in synching to the milli second level. #...
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2answers
1k views

Is it possible to increase the voltage on 3.3v output to 5v on an ESP board to power a DC motor? [closed]

I am trying to use an ESP32s controller connected to an RC car DC motor. I found that when using my Arduino this is easily accomplished, and I can see that my output pin produces 5v for the motor to ...
1
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1answer
229 views

Programming ESP32 MCUs for production

Before committing to learning about the ESP32 and how to program it, I would like to know if the ESP can be programme the same way for production as it can on évaluation boards (with the Arduino IDE). ...
1
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1answer
42 views

Webpage values wont update

I've been trying to run the following esp32 LED PWM code to change the LED's brightness, and show the current PWM duty on the webpage, but the PWM values on the webpage won't change until I hit the ...
1
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1answer
840 views

String does not name a type

I'm using Arduino IDE for ESP32 WROOM board. I am testing the OTA feature with the ESP32httpUpdate library. I am using the example sketch of the library with the name httpUpdate.ino However, as soon ...
1
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1answer
893 views

How arduino boards eliminate the need to press buttons to flash?

I've come across many Arduino shields for various boards like the Uno, ESP8266, and ESP32 which sometimes have a button for flashing and other times they do not because the flashing is automatic. ...
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1answer
1k views

Increase sample rate in ESP32 board

For my final project on the university as a Systems Engineer, I'm working on a "electronic stethoscope", which is giving me a lot of headaches. I bought a Adafruit Feather ESP32 Huzzah (https://learn....
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1answer
71 views

Anyone have example code for ESP32 as media controller for Android/iPhone Media Apps

There's actually another post with this very same topic but no answers on that post. Back in January of 2020, the last commenter said he had sample code and then he went dark without posting the ...
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1answer
1k views

ESP32 seconds from epoch

When using ESP8266 - getting seconds from epoch is done using NTP.begin(NTPserver, 2, true); delay(delay_tries); time_t t = now(); while t stores amount of seconds from 1-1-1970. When trying to do ...
1
vote
1answer
145 views

test for wrong wifi password?

maybe this is a dumb question, but is there a way to test for wrong wifi password, I know you can do WL_CONNECT to check if the password works, but is there a command for checking if the password is ...
1
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1answer
630 views

Firmware backup and restore

I need to have the firmware stored somewhere on the board in order to get back to it after flashing a new firmware. Is there a way to store a backup of the firmware somewhere, and use a button to ...
1
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2answers
3k views

Constant ADC sampling rate on ESP8266 or ESP32

I want to sample Sound input with either an ESP8266 (preferred) or ESP32. As I'm using a low pass filter anyway, a sample rate of 1000-2000hz would be totally ok. What is more important, is that it is ...
1
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1answer
170 views

PUT request: PHP code to Arduino HTTPClient

I'm uploading a file to Azure blob storage using REST API request. The file uploaded successfully using PHP curl request. But when I transfer the code into ESP32 HTTP client I'm getting an ...

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