Hello, I’m starting out with PlatformIO and ESP32 and I am trying to get the arduino simple wifi server sketch to work.:
#include <Arduino.h>
#include <WiFi.h>
const char* ssid = "Rajat's WiFi";
const char* password = "*********";
WiFiServer server(80);
void setup() {
Serial.begin(115200);
pinMode(LED_BUILTIN, OUTPUT); // set the LED pin mode
delay(10);
// We start by connecting to a WiFi network
Serial.println();
Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.println("WiFi connected.");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
server.begin();
}
int value = 0;
void loop () {
WiFiClient client = server.available();
if (client) { // if you get a client,
Serial.println("New Client."); // print a message out the serial port
String currentLine = ""; // make a String to hold incoming data from the client
while (client.connected()) { // loop while the client's connected
if (client.available()) { // if there's bytes to read from the client,
char c = client.read(); // read a byte, then
Serial.write(c); // print it out the serial monitor
if (c == '\n') { // if the byte is a newline character
// if the current line is blank, you got two newline characters in a row.
// that's the end of the client HTTP request, so send a response:
if (currentLine.length() == 0) {
// HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
// and a content-type so the client knows what's coming, then a blank line:
client.println("HTTP/1.1 200 OK");
client.println("Content-type:text/html");
client.println();
// the content of the HTTP response follows the header:
client.print("Click <a href=\"/H\">here</a> to turn the LED on pin 5 on.<br>");
client.print("Click <a href=\"/L\">here</a> to turn the LED on pin 5 off.<br>");
// The HTTP response ends with another blank line:
client.println();
// break out of the while loop:
break;
} else { // if you got a newline, then clear currentLine:
currentLine = "";
}
} else if (c != '\r') { // if you got anything else but a carriage return character,
currentLine += c; // add it to the end of the currentLine
}
// Check to see if the client request was "GET /H" or "GET /L":
if (currentLine.endsWith("GET /H")) {
digitalWrite(LED_BUILTIN, HIGH); // GET /H turns the LED on
}
if (currentLine.endsWith("GET /L")) {
digitalWrite(LED_BUILTIN, LOW); // GET /L turns the LED off
}
}
}
// close the connection:
client.stop();
Serial.println("Client Disconnected.");
}
}
It compiles and uploads fine, but as soon as I open the PlatformIO serial monitor, I get the error Guru Meditation Error: Core panic'ed (Interrupt wdt timeout on CPU0) and the MCU stops working. Note that the regular arduino serial monitor never shows this problem.
I need the serial monitor for the time being for debugging purposes, I would be grateful if someone points me out the problem.
My platformio.ini:
[env:nodemcu-32s]
platform = espressif32
board = nodemcu-32s
framework = arduino
monitor_speed = 115200
The sketch you’ve linked to is for a board having a WiFi shield. Not an ESP32. Are you sure you don’t want to run HelloServer.ino?
I’m sorry. I thought that’s the default wifi sketch that comes with the Arduino IDE because it looked same. I’ll update with the whole code.
Anyway, I just noticed that if I put the ESP32 on a breadboard instead of holding in my hand/leaving it on my table with floating pins, the problem goes away. What’s bugging me is that the Arduino’s serial monitor just works, no matter what. Why does PlatformIO’s serial monitor cause my MCU to crash?
That would be beyond weird if that was the case. If you flashed the (wrong) firmware via PlatformIO and observe the serial monitor in PlatformIO, it should give the same result as in the Arduino IDE serial monitor, if the firmware is not re-uploaded in the Arduino IDE. The firmware should be the cause of the crash, not the serial monitor.
Hmm… spooky stuff.
- I compile and upload the program using platform io, it does that successfully
- I press the reset button, it works, connects to the router, and I can find a corresponding ip in my router. I can see the webpage it serves at the ip. Everything works as expected.
- I open the platform io serial monitor to check the outputs, and it immediately crashes the MCU. I won’t be able to find the ip anymore.
- I close the platform io serial monitor, open Arduino ide, open serial monitor, reset the MCU, it works as expected and Arduino ide serial monitor displays everything as expected.
- I close Arduino ide, open platform io’s serial monitor, it crashes immediately.
etc…
Meanwhile I’m using the MCU being plugged into a breadboard, but as is well known I think, ESP32 dev boards fit awkwardly in a breadboard, but that seems to solve the problem. Maybe it’s because of loose connections and a poorly developed error checking/unsafe serial buffer implementation of the serial terminal in PlatformIO?
Only thing I can tell is that it is reproducible with 3 different ESP32 dev boards I have, so it’s not particular to the one I used initially.
Is the crash reproducable when you press the reset button on the board again?
Yes. If I keep PlatformIO’s serial monitor open then when resetting, it crashes at a random point. Sometimes right at the beginning, most of the times during WiFi.begin(ssid, password);, and sometimes in the loop(). But it does crash, sooner or later.
Can you add
build_type = debug
monitor_filters = esp32_exception_decoder
to the platformio.ini to get a better crash log, and post that?
Also what version of the Arduino ESP32 core do you have installed in the Arduino IDE? The very latest 2.0 version?
It’s so weird… As I said, I was using the ESP32 board plugged into a breadboard and it was working fine with PlatformIO’s serial monitor and as soon as I took it out and tried uploading/running it again, the crashes are back. Anyway, here’s what you asked:
Connecting to Rajat's WiFi
....p��ՁMeditation Error: Core� 0 panic'ed (IllegalInstruction). Exception was unhandled.
Memory dump at ��0089958: 190c020c 209329���
�17420
Core 0 registe��"յ��
PC : 0x400899��c PS : 0x00060433 A�� : 0x8008587e A1 ����ffb5700
A2 :���0000000 A3 : 0x0�������
� : 0x00060���
� : 0x00000001 ����� : ��0060820 �����`000000 A8 : 0x00000000 A9 : 0x00000001
A10 : 0x00060420 A11 : 0x00060823 A12 : 0x00060820 A13 : 0x3ffb5768
A14 : 0x00000019 A15 : 0x001fb475 SAR : 0x00000018 EXCCAUSE: 0x00000000
EXCVADDR: 0x00000000 LBEG : 0x4000c2e0 LEND : 0x4000c2f6 LCOUNT : 0xffffffff
ELF file SHA256: 0000000000000000
Backtrace: 0x4008995c:0x3ffb5700 0x4008587b:0x3ffb5720 0x40083f9f:0x3ffb5740 0x40102a40:0x3ffb5760 0x40089832:0x3ffb5790
#0 0x4008995c:0x3ffb5700 in xPortInIsrContext at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/freertos/port.c:355 (discriminator 1)
#1 0x4008587b:0x3ffb5720 in wifi_bt_common_module_enable at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/driver/periph_ctrl.c:263
#2 0x40083f9f:0x3ffb5740 in esp_phy_common_clock_enable at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/esp32/phy_init.c:524
#3 0x40102a40:0x3ffb5760 in ppTask at ??:?
#4 0x40089832:0x3ffb5790 in vPortTaskWrapper at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/freertos/port.c:355 (discriminator 1)
Rebooting...
ets Jun 8 2016 00:22:57
rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0018,len:4
load:0x3fff001c,len:1044
load:0x40078000,len:10124
load:0x40080400,len:5828
entry 0x400806a8
Connecting to Rajat's WiFi
....Guru Meditation Error: Core panic'ed (Interrupt wdt timeout on CPU0)
Core 0 register dump:
PC 0x40086c2 PS 0x00060434 A0 0x80102aa A1 0x3fb730
A2 0x00000000 A3 0xffff A4 0x00000001 A5 0x3f73c4
A6 0x3f74270 A7 0x3fb1f A8 0x400f240 A9 0x3f08414
A10 0x00000000 A11 0x0000007f A12 0x3f73c4 A13 0x00000001
A14 0x3fcb4 A15 0x00000000 SAR 0x00000020 EXCCAUSE 0x00000005
EXCVADDR 0x00000000 LBEG 0x4000ce LEND 0x4000cf LCOUNT 0xffff
ELF file SHA256: 000000000000000
Backtrace:0x40086c2:0x3fb7300x40102a7:0x3fb760 0x40089832:0x3fb790
#0 0x40086c2:0x3fb7300 in ?? ??:0
ore 1 register dump:
PC 0x401429b PS 0x00060c4 A0 0x80131056 A1 0x3fb680
A2 0x00000000 A3 0x80000001 A4 0x00000000 A5 0x00000001
A6 0x00060c0 A7 0x00000000 A8 0x00060023 A9 0x3fb77c
A10 0x00000001 A11 0x00000001 A12 0x80089a4 A13 0x3fb580
A14 0x00000000 A15 0x3fb380 SAR 0x00000000 EXCCAUSE 0x00000005
EXCVADDR 0x00000000 LBEG 0x00000000 LEND 0x00000000 LCOUNT 0x00000000
ELF file SHA256: 000000000000000
Backtrace:0x401429b:0x3fb6800x40131053:0x3fb6a 0x4008ae:0x3fb6c 0x40089832:0x3fb6e
#0 0x401429b:0x3fb6800 in ?? ??:0
Rebooting...
In the Arduino boards manager, it says Esp32 2.0.0-alpha 1.
Hm… I’ve never seen that type of backtrace before where it crashes in… xPortInIsrContext.
PlatformIO in its latest release uses 1.0.6. Does it behave like that in the Arduino IDE when you install that version? (You can always switch back)
I tried to change versions, it downloaded and installed, v1.0.6 onwards disappeared from version selection, but it still shows v2.0.0-alpha 1. And the program doesn’t crash. I can’t remove and add it again it either. It shows some java null pointer exception if I try to remove it. 
o_o that’s not good. In extreme cases try to restart the Arduino IDE are reinstall it. The core is always re-installable and you can backup existing libraries in C:\Users\<user>\Documents\Arduino\libraries.
Though I don’t have any idea why the program is behaving eratically in the first place. Sounds like a hardware issue if it works inside a breadboard but not outside… But then again why would it work in the Arduino IDE and not PlatformIO.
Yeah. I’ll try reinstalling and update on this later. Meanwhile I should mention platform io’s flashing feels weird too. I don’t have to hold the programming button on MCU board, it right away starts flashing. With Arduino ide, it waits till I hold the programming button down for a while. And all of these problems are reproducible on all 3 boards I have. I just got them yesterday.
Nope I checked. No problem with v1.0.6 in Arduino IDE. And PlatformIO’s serial monitor keeps crashing my MCU randomly with the typical output:
rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
flash read err, 1000
ets_main.c 371
ets Jun 8 2016 00:22:57
rst:0x10 (RTCWDT_RTC_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff0018,len:4
load:0x3fff001c,len:1044
load:0x40078000,len:10124
load:0x40080400,len:5856
entry 0x400806a8
Connecting to Rajat's WiFi
....Guru Meditation Error: Core panic'ed (Interrupt wdt timeout on CPU0)
Core 0 register dump:
PC 0x40086c2 PS 0x00060434 A0 0x801017d A1 0x3fb6e
A2 0x00000a8 A3 0x000000a A4 0x10892018 A5 0x3fcf4
A6 0x00000000 A7 0x3fb138 A8 0x00000001 A9 0x3fc174
A10 0x00000000 A11 0x00000000 A12 0x00000000 A13 0x00000001
A14 0x00060420 A15 0x00000000 SAR 0x00000019 EXCCAUSE 0x00000005
EXCVADDR 0x00000000 LBEG 0x4000ce LEND 0x4000cf LCOUNT 0xffff
ELF file SHA256: 000000000000000
Backtrace:0x40086c2:0x3fb6e 0x401017d:0x3fb760 0x400897f:0x3fb790
#0 0x40086c2:0x3fb6e in ?? ??:0
#1 0x401017d:0x3fb760 in ?? ??:0
#2 0x400897f:0x3fb790 in ?? ??:0
ore 1 register dump:
PC 0x401411d PS 0x00060e4 A0 0x8012f32 A1 0x3fb680
A2 0x00000000 A3 0x00000001 A4 0x80089ac A5 0x3fb5a
A6 0x00000000 A7 0x3fb380 A8 0x00000020 A9 0x80000020
A10 0x00000008 A11 0x00000001 A12 0x00000005 A13 0x00000020
A14 0x00000020 A15 0x10000000 SAR 0x00000000 EXCCAUSE 0x00000005
EXCVADDR 0x00000000 LBEG 0x00000000 LEND 0x00000000 LCOUNT 0x00000000
ELF file SHA256: 000000000000000
Backtrace:0x401411d:0x3fb6800x4012f2f0x3fb6a 0x4008aa:0x3fb6c 0x400897f:0x3fb6e
#0 0x401411d:0x3fb6800 in ?? ??:0
Rebooting...
I hope someone sheds some light into this.
Ive done a number of ESP32 projects all using Platform IO. Can you post your project platformio.ini file?
I already put it in the question as I thought it’s important too. It’s just
[env:nodemcu-32s]
platform = espressif32
board = nodemcu-32s
framework = arduino
monitor_speed = 115200
PlatformIO in its latest release uses 1.0.6.
This became a problem to me today. ESP32’s bluetooth master mode/discovery mode doesn’t seem to work with old versions. I’m talking about this example. I feel bad for having to leave a real IDE in favor of arduino IDE 
If you really-really want to use this 2.0.0-alpha version, you can follow ESP32-Arduino - platformio support for 2.0.0 version - #2 by maxgerhardt to use it.
When I take the above code as src\main.cpp, add a #include <Arduino.h> in front of it and use with a platformio.ini of
[env:esp32dev]
platform = espressif32
board = esp32dev
framework = arduino
platform_packages =
toolchain-xtensa32 @ ~2.80400.0
framework-arduinoespressif32@https://github.com/espressif/arduino-esp32.git#2.0.0-alpha1
monitor_speed = 115200
I get a successfull build
Advanced Memory Usage is available via "PlatformIO Home > Project Inspect"
RAM: [= ] 7.2% (used 23436 bytes from 327680 bytes)
Flash: [======= ] 69.7% (used 913716 bytes from 1310720 bytes)
Building .pio\build\esp32dev\firmware.bin
esptool.py v3.0
============ [SUCCESS] Took 16.79 seconds ============
and if I upload & monitor
rst:0x10 (RTCWDT_RTC_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0030,len:1252
load:0x40078000,len:12692
load:0x40080400,len:3100
entry 0x400805ec
The device started, now you can pair it with bluetooth!
Starting discoverAsync...Findings will be reported in "btAdvertisedDeviceFound"
Found a device asynchronously: Name: Redmi max, Address: b4:c4:fc:42:xx:xx, cod: 58987, rssi: -61
Stopping discoverAsync... stopped
Starting discover...
>> Dump scan results: 1
- 1: Name: Redmi max, Address: b4:c4:fc:42:xx:xx, cod: 58987, rssi: -55
-- Dump finished --
1 Like
OOF BIG THANKS. After a little bit of tinkering(installing git, I already had git in visual studio but it didn’t work outside VS, and updating esptoolpy, letting intellisense rebuild indexes for quite some time) it finally compiles!
Thanks a bunch!!
I always use the following in my platformio.ini file for all my ESP32 projects
[env:esp32doit-devkit-v1]
platform = espressif32
board = esp32doit-devkit-v1
framework = arduino
monitor_speed = 115200