Ok,
This is doing my head in - am trying to read a webpage off the server with CSV file and use it to change colours on an LED strip.
- Connection to wifi works
- Logs into server fine
- extracts the page content fine
- returns it to the Arduino as variable 'c'
- then it borks when I try to convert this webpage text into a String that can be read.
Anyone offer any tips on why I'm getting the below error? I know the code is pretty cruddy, so any help appreciated - I'm just trying to understand Arduino as it's awesomely powerful!
char c = client.read();
String webLedFeed = c;
Error:
HomeServer.ino: In function 'void loop()':
HomeServer:71: error: invalid conversion from 'char' to 'const char*'
HomeServer:71: error: initializing argument 1 of 'String::String(const char*)'
#include <SPI.h>
#include <WiFi.h>
char ssid[] = "*****"; // your network SSID (name)
char pass[] = "****"; // your network password
int keyIndex = 0; // your network key Index number (needed only for WEP)
int status = WL_IDLE_STATUS;
// Initialize the Wifi client library
WiFiClient client;
// server address:
char server[] = "192.168.0.102";
unsigned long lastConnectionTime = 0; // last time you connected to the server, in milliseconds
boolean lastConnected = false; // state of the connection last time through the main loop
const unsigned long postingInterval = 10*1000; // delay between updates, in milliseconds
void setup() {
//Initialize serial and wait for port to open:
Serial.begin(9600);
while (!Serial) {
; // wait for serial port to connect. Needed for Leonardo only
}
// check for the presence of the shield:
if (WiFi.status() == WL_NO_SHIELD) {
Serial.println("WiFi shield not present");
// don't continue:
while(true);
}
// attempt to connect to Wifi network:
while ( status != WL_CONNECTED) {
Serial.print("Attempting to connect to SSID: ");
Serial.println(ssid);
// Connect to WPA/WPA2 network. Change this line if using open or WEP network:
status = WiFi.begin(ssid, pass);
// wait 10 seconds for connection:
delay(3000);
}
// you're connected now, so print out the status:
printWifiStatus();
}
void loop() {
// if there's incoming data from the net connection.
// send it out the serial port. This is for debugging
// purposes only:
while (client.available()) {
char c = client.read();
String webLedFeed = c;
// Serial.write(webLedFeed);
// PARSE CSV -START
uint8_t redLed, greenLed, blueLed;
int timeLit;
if (sscanf(webLedFeed.c_str(), "!!!!!%hhu,%hhu,%hhu,%d!!!!!", &redLed, &greenLed, &blueLed, &timeLit) == 4)
{
Serial.println("redLED= ");
Serial.println(redLed);
Serial.println("greenLED= ");
Serial.println(greenLed);
Serial.println("blueLED= ");
Serial.println(blueLed);
Serial.println("Time= ");
Serial.println(timeLit);
}
else
{
Serial.println("No data received");
}
// PARSE CSV - END
}
// if there's no net connection, but there was one last time
// through the loop, then stop the client:
if (!client.connected() && lastConnected) {
Serial.println();
Serial.println("disconnecting.");
client.stop();
}
// if you're not connected, and ten seconds have passed since
// your last connection, then connect again and send data:
if(!client.connected() && (millis() - lastConnectionTime > postingInterval)) {
httpRequest();
}
// store the state of the connection for next time through
// the loop:
lastConnected = client.connected();
}
// this method makes a HTTP connection to the server:
void httpRequest() {
// if there's a successful connection:
if (client.connect(server, 80)) {
Serial.println("connecting...");
// send the HTTP PUT request:
client.println("GET /homeserver/latest.txt HTTP/1.1");
client.println("Host: 192.168.0.102");
client.println("User-Agent: arduino-ethernet");
client.println("Connection: close");
client.println();
// note the time that the connection was made:
lastConnectionTime = millis();
}
else {
// if you couldn't make a connection:
Serial.println("connection failed");
Serial.println("disconnecting.");
client.stop();
}
}
void printWifiStatus() {
// print the SSID of the network you're attached to:
Serial.print("SSID: ");
Serial.println(WiFi.SSID());
// print your WiFi shield's IP address:
IPAddress ip = WiFi.localIP();
Serial.print("IP Address: ");
Serial.println(ip);
// print the received signal strength:
long rssi = WiFi.RSSI();
Serial.print("signal strength (RSSI):");
Serial.print(rssi);
Serial.println(" dBm");
}
Hmm, can you tell I'm learning........!