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LadyN

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Joined: 26/01/2019
Location: United States
Posts: 408

Posted: 07:13pm 28 Mar 2019

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I just wanted to clarify that the ESP32 WiFi chip has a functional Arduino core:

https://github.com/espressif/arduino-esp32

When I get excited about the ESP32 WiFi chip when we discuss Arduino projects, I am not talking about the IDF toolchain but this Arduino core.

In theory, your Arduino projects should continue to run on the ESP32 using the Arduino core for ESP32 WiFi chip. OF COURSE, hardware specific assumptions will need to be updated but you all knew that already!

mackoffgrid

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Joined: 13/03/2017
Location: Australia
Posts: 460

Posted: 09:52pm 28 Mar 2019

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I've recently bought a ESP32 (I think its the 32 and not the 8266) but haven't played with it yet. How different is the ESP32 from the ESP8266?

LadyN

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Joined: 26/01/2019
Location: United States
Posts: 408

Posted: 02:09am 29 Mar 2019

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I REALLY LACK the hands on experience to answer this question properly and will let professionals do a better job.

I believe that they are not comparable at all. The ESP32 is in a completely different league.

The price is what excites me. The ESP32 is not even double the price of a ESP8266 hence the price/feature ratio is absolutely incomparable.

I found this to be useful: https://makeradvisor.com/esp32-vs-esp8266/

mackoffgrid

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Posted: 02:20am 29 Mar 2019

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looks like I got the wrong one ?
ESP 8266 ?

can you recommend an esp32 on Aliexpress or ebay?

LadyN

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Posts: 408

Posted: 03:00am 29 Mar 2019

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Yes that's not the ESP32 Andrew

Hmm,

I looked at my order history and the prices have gone up a bit but these are the two types I like to buy:

https://www.aliexpress.com/item/Wifi-Bluetooth-Development-Board-Antenna-ESP32-ESP-32-REV1-CH340-CH340G-MicroPython-Micr o-USB-Lithium-Battery/32846143452.html

https://www.aliexpress.com/item/ESP-32-ESP-32S-Development-Board-WiFi-Bluetooth-Ultra-Low-Power-Consumption-Dual-Cores-E SP32-Board/32959078656.html

If you want to buy only 1 to test, get the second one.

mackoffgrid

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Posts: 460

Posted: 03:54am 29 Mar 2019

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They're both ok with arduino IDE (windows)?

I'll get one if that the case.

2 cores, that'll be interesting.

Thanks
Andrew

LadyN

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Posted: 05:35pm 29 Mar 2019

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mackoffgrid said They're both ok with arduino IDE (windows)?

Yes.

The two boards I posted are not the same. One has an additional 4MB Winbond memory on it that might be useful for the Warpverter project but the other one I recommend has better pin routing that's very useful when starting off with these ESP32s

mackoffgrid

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Posted: 12:15am 30 Apr 2019

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Hi Natasha

I haven't ordered one of those ESP32 modules yet. That last link you posted doesn't seem to work now. Could you look at the following link and confirm the suitability for arduino use. Do you have other suggestions - better options?

ailExpress ESP32

Cheers
AndrewEdited by mackoffgrid 2019-05-01

LadyN

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Posted: 07:08pm 30 Apr 2019

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Hi Andrew !

That model looks OK but it's not the best price.

Try removing spaces from the links I posted - I JUST confirmed they still work. IT MIGHT be possible the filter results based of country?

My first link uses CH340G and a 4MB Winbond flash - never used it as these are relatively new before but I have used a lot of the second link (and the one you posted) and they are painless.

I THINK TinyT posted some results that bitbanging on these ESP32 are not reliable.

He's right because they run RTOS but there is a RMT peripheral on these ESP32 that can be used to send out bitperfect waveforms so if you can explore that I would really appreciate it.

I will be doing some ULP experiments myself for my solar power monitor

mackoffgrid

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Posted: 10:34pm 30 Apr 2019

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Thanks,
I have no specific project or target but the embeded wifi and bluetooth make it interesting for a start. The dual cores are also interesting, perhaps a positive and a negative. At the moment, the BluePill is my goto if you need good ADC and timing, at a price, and in a convenient form factor.

Cheers
Andrew

poida

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Joined: 02/02/2017
Location: Australia
Posts: 1419

Posted: 06:09am 01 May 2019

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the above aliexpress link is to the same sort of esp32 I bought.
It works fine, using the Arduino software.

I posted something here earlier about non-deterministic timing for pin i/o.

You need to install a few extra things, to make it work within a vanilla Arduino install.

follow info at
https://github.com/espressif/arduino-esp32

I had no problems programming and running it.
an example, that has reliable connection and reconnection the the wifi.

It shows a simple web page and has two buttons, which control the LED and another GPIO pin. tap the button (on the mobile phone) and the LED lights up or dims.
proof of concept stuff.

#include <WiFi.h>
#include <WebServer.h>

/* Put your SSID & Password */
const char* ssid = "something"; // Enter SSID here
const char* password = "its a secret.."; //Enter Password here

WebServer server(80);

uint8_t LED1pin = 4;
bool LED1status = LOW;

uint8_t LED2pin = 2;
bool LED2status = LOW;

void setup()
{
int t;
Serial.begin(115200);
pinMode(LED1pin, OUTPUT);
pinMode(LED2pin, OUTPUT);

again_plz:
t=0;
WiFi.disconnect();
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
t++;
if (t > 10)
goto again_plz;
}

Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
for(t=0; t < 5; t++)
{
digitalWrite(2,HIGH);
delay(100);
digitalWrite(2,LOW);
delay(100);
}

server.on("/", handle_OnConnect);
server.on("/led1on", handle_led1on);
server.on("/led1off", handle_led1off);
server.on("/led2on", handle_led2on);
server.on("/led2off", handle_led2off);
server.onNotFound(handle_NotFound);

server.begin();
Serial.println("HTTP server started");
}

void loop()
{
server.handleClient();
if(LED1status)
{digitalWrite(LED1pin, HIGH);}
else
{digitalWrite(LED1pin, LOW);}

if(LED2status)
{digitalWrite(LED2pin, HIGH);}
else
{digitalWrite(LED2pin, LOW);}
}

void handle_OnConnect() {
LED1status = LOW;
LED2status = LOW;
Serial.println("GPIO4 Status: OFF | GPIO5 Status: OFF");
server.send(200, "text/html", SendHTML(LED1status,LED2status));
}

void handle_led1on() {
LED1status = HIGH;
Serial.println("GPIO4 Status: ON");
server.send(200, "text/html", SendHTML(true,LED2status));
}

void handle_led1off() {
LED1status = LOW;
Serial.println("GPIO4 Status: OFF");
server.send(200, "text/html", SendHTML(false,LED2status));
}

void handle_led2on() {
LED2status = HIGH;
Serial.println("GPIO5 Status: ON");
server.send(200, "text/html", SendHTML(LED1status,true));
}

void handle_led2off() {
LED2status = LOW;
Serial.println("GPIO5 Status: OFF");
server.send(200, "text/html", SendHTML(LED1status,false));
}

void handle_NotFound(){
server.send(404, "text/plain", "Not found");
}

String SendHTML(uint8_t led1stat,uint8_t led2stat){
String ptr = "<!DOCTYPE html> <html>\n";
ptr +="<head><meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0, user-scalable=no\">\n";
ptr +="<title>LED Control</title>\n";
ptr +="<style>html { font-family: Helvetica; display: inline-block; margin: 0px auto; text-align: center;}\n";
ptr +="body{margin-top: 50px;} h1 {color: #444444;margin: 50px auto 30px;} h3 {color: #444444;margin-bottom: 50px;}\n";
ptr +=".button {display: block;width: 80px;background-color: #3498db;border: none;color: white;padding: 13px 30px;text-decoration: none;font-size: 25px;margin: 0px auto 35px;cursor: pointer;border-radius: 4px;}\n";
ptr +=".button-on {background-color: #3498db;}\n";
ptr +=".button-on:active {background-color: #2980b9;}\n";
ptr +=".button-off {background-color: #34495e;}\n";
ptr +=".button-off:active {background-color: #2c3e50;}\n";
ptr +="p {font-size: 14px;color: #888;margin-bottom: 10px;}\n";
ptr +="</style>\n";
ptr +="</head>\n";
ptr +="<body>\n";
ptr +="<h1>ESP32 Web Server</h1>\n";
ptr +="<h3>nothing in particular</h3>\n";

if(led1stat)
{ptr +="<p>LED1 Status: ON</p><a class=\"button button-off\" href=\"/led1off\">OFF</a>\n";}
else
{ptr +="<p>LED1 Status: OFF</p><a class=\"button button-on\" href=\"/led1on\">ON</a>\n";}

if(led2stat)
{ptr +="<p>LED2 Status: ON</p><a class=\"button button-off\" href=\"/led2off\">OFF</a>\n";}
else
{ptr +="<p>LED2 Status: OFF</p><a class=\"button button-on\" href=\"/led2on\">ON</a>\n";}

ptr +="</body>\n";
ptr +="</html>\n";
return ptr;
}

wronger than a phone book full of wrong phone numbers

mackoffgrid

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Joined: 13/03/2017
Location: Australia
Posts: 460

Posted: 07:41am 01 May 2019

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Thanks Poida. I appreciate the head start.

I can see the esp32 will be very useful for IOT etc.

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