ESP8266 Shiald Progress!

I’m really tired, but while trying to watch TV got to thinking about the Wifi board I’ve been playing with (described in previous post). I’d got as far as loading firmware that allowed it to speak AT codes. Couldn’t resist having a quick look at what could be done next. Luckily I went to my bookmarks first rather than looking at my notes here, because there was a page I must have bookmarked early on and forgotten about : Arduino UNO + ESP8266 ESP-12E UART WIFI Shield. It contains code for a minimal web server.

Looking at an image in this post reveals that the Shield there is there very same Shiald [sic] I have. Only problem, the author uses a USB-serial adapter to talk to it, something I don’t have. But wait – I found a way of rigging the Arduino to act as such an adapter (previous post).

I saw somewhere, and confirmed (by using a tablet to scan for WiFi networks) that the default IP address for the Shiald is rather an obscure one, off my local subnet anyway. But a bit of googling gave me the info necessary to set the IP to something else.

After fiddling a bit with the baud rate, a little blue light started flashing next to the ESP8266 chip, and it worked!

In the IDE:

Screenshot from 2018-02-07 23-07-57

In the Serial console:

Screenshot from 2018-02-07 23-11-12

Screenshot from 2018-02-07 23-11-35

And in a browser! Woo-hoo!

Screenshot from 2018-02-07 22-45-33

Here’s my tweaked version of the script:

#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
const char* ssid = "AllPay Danny";
const char* password = "not this";
ESP8266WebServer server(80); // HTTP server on port 80

IPAddress ip(192, 168, 0, 14); // where xx is the desired IP Address
IPAddress gateway(192, 168, 0, 1); // set gateway to match your network
IPAddress subnet(255, 255, 255, 0); // set subnet mask to match your network

void setup() {
 Serial.begin(115200); 
 WiFi.disconnect(); // Disconnect AP
 
 WiFi.config(ip, gateway, subnet);
 
 WiFi.mode(WIFI_STA); 
 WiFi.begin(ssid, password); // Connect to WIFI network
// Wait for connection
 while (WiFi.status() != WL_CONNECTED) {
 delay(500);
 Serial.println(".");
 }
 Serial.print("Connected to ");
 Serial.println(ssid);
 Serial.print("IP address: ");
 Serial.println(WiFi.localIP());
server.on("/", [](){
 server.send(200, "text/plain", "Hello World");
 });
server.begin(); // Start HTTP server
 Serial.println("HTTP server started.");
}
void loop() {
 server.handleClient();
}

The blog post goes on to Part 2 Upload code to Arduino, which I’ll try next – when I’m properly rested 🙂

PS.

Just tried this Part 2 bit, essentially comms between Shiald & Arduino. It nearly worked :

Data received: . .
Conoected to AllPay Danoy
IP address: 092.168.0.04C!⸮⸮⸮⸮ٕɁ⸮⸮

I’ve read somewhere that the Software Serial struggles at high baud rates, and this example is using 115200 so presumably that’s the problem. Bit of tweaking required.

PPS.

I flipped the baud rate in the code based on that in the blog post to 9600, and with the Arduino as serial converter uploaded the new code to the Shiald (at 115200 baud), set as NodeMCU 1.0. Uploading took a good few attempts, but finally it worked.

I also changed the Arduino part of the code to use different ports :

#include <SoftwareSerial.h>
SoftwareSerial mySerial(2, 3); // RX, TX on Arduino
void setup() {
 Serial.begin(9600);
 mySerial.begin(9600);
}
void loop() {
 if (mySerial.available()) {
 String msg = mySerial.readString();
 Serial.print("Data received: ");
 Serial.println(msg);
 }
}

The wiring I now have as :

Arduino   | Shiald

GND       - Debug GND
+5v       - Debug 5v
Digital 2 - Digital 0
Digital 3 - Digital 1

The switches on the Shiald are at (1,2,3,4) On, On, Off, Off.

And finally, the Hello World is still visible on the IP address I set. And what’s more, in the serial monitor (now set to 9600 baud) I see:

Connected to AllPay Danny
IP address: 192.168.0.14
HTTP server started.

Yay! It all works.

So…

Next

First thing I should do is pull together all the various bits from the last post and this, with relevant material from linked pages, and write it up as a from scratch to here procedure. I won’t remember, and also anyone that buys the same boards will stand a chance of getting things going.

Then I need to think about what I’m going to do on the analog/sensor side. What I can do with the hardware I’ve got is fairly limited – a key factor being the speed of the data acquisition on the Arduino. But I should have the necessary for me to build something that operates end-to-end with essentially the same topology as my target design.

Regarding code on the Arduino & Shiald, the next steps will be to :

  1. Get the data from the single Analog Input on the Shiald, buffer/filter it and expose it on a local web server. With a little analog pre-amp & filter this should be enough for a single-channel seismometer.
  2. Do the code necessary on a regular computer to access and do something with the data from the web server on the Shiald.
  3. Get the data from the 6 Analog Inputs on the Arduino, buffer/filter it, transfer it to the Shiald and again expose on a local web server. I might well try the analog bandpass filter idea mentioned in my previous post.
  4. As 2. but for the 6 channels.

A global job to put together in parallel with the above is the code necessary for self-description of the units to provide status information alongside the data. RDF and Web of Things time!

So now I’ve got fairly fun jobs to get on with on every side of this project :

  1. Sensor hardware
  2. Arduino/Shiald software
  3. Comms/post-processing software – I can get on with the Deep Learning bits using online sources, haven’t looked at that for weeks
  4. Notification system – hook the Deep Learning bit output to Twitter

I may have to get the dice out…

//// note to self

danny@lappie:/dev$ esptool.py --port ttyACM0 --baud 9600 flash_id
esptool.py v2.2.1
Connecting........_____....._____
Detecting chip type... ESP8266
Chip is ESP8266EX
Uploading stub...
Running stub...
Stub running...
Manufacturer: c8
Device: 4016
Detected flash size: 4MB
Hard resetting...
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Author: Danny Ayers

Web research and development, music geek, woodcarver. Originally from rural northern England, now based in rural northern Italy.

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