Merge pull request #370 from Links2004/esp8266

add better docu and schematics for easy setup the ESP

Author: igrr

README.md

@@ -206,6 +206,28 @@ Libraries that don't rely on low-level access to AVR registers should work well.
 Pick the correct serial port.
 You need to put ESP8266 into bootloader mode before uploading code.
 
+#### Power Supply ####
+
+For stable use of the ESP8266 a power supply with 3V3 and >= 250mA is required.
+
+* Note
+ - using Power from USB to Serial is may unstable, they not deliver enough current. 
+ 
+#### Serial Adapter ####
+ 
+There are many different USB to Serial adapters / boards.
+
+* Note
+ - for full upload management you need RTS and DTR
+ - the chip need to have 3V3 TTL (5V may damage the chip)
+ - not all board have all pins of the ICs as breakout (check before order)
+ - CTS and DSR are not useful for upload (they are Inputs)
+
+* Working ICs 
+ - FT232RL
+ - CP2102
+ - may others (drop a comment)
+  
 #### Minimal hardware Setup for Bootloading and usage ####
 
 ESPxx Hardware
@@ -226,26 +248,43 @@ ESPxx Hardware
  - Reset is also named RSBT or REST (adding PullUp improves the stability of the Module)
  - GPIO2 is alternative TX for the boot loader mode
 
-ESP01 example:
-
-![ESP01 connect](https://raw.githubusercontent.com/Links2004/Arduino/esp8266/docs/ESP01_connect.jpg)
+###### esp to Serial
+![ESP to Serial](https://raw.githubusercontent.com/Links2004/Arduino/esp8266/docs/ESP_to_serial.png)
 
 #### Minimal hardware Setup for Bootloading only ####
 ESPxx Hardware
 
-| PIN           | Resistor | Serial Adapter |
-| ------------- | -------- | -------------- | 
-| VCC           |          | VCC (3.3V)     |
-| GND           |          | GND            |
-| TX or GPIO2   |          | RX             |
-| RX            |          | TX             |
-| GPIO0         |          | GND            |
+| PIN           | Resistor | Serial Adapter  |
+| ------------- | -------- | --------------- | 
+| VCC           |          | VCC (3.3V)      |
+| GND           |          | GND             |
+| TX or GPIO2   |          | RX              |
+| RX            |          | TX              |
+| GPIO0         |          | GND             |
 | Reset         |          | RTS*            |
-| GPIO15        | PullDown |                |
-| CH_PD         | PullUp   |                |
+| GPIO15        | PullDown |                 |
+| CH_PD         | PullUp   |                 |
 
 * Note 
 	- if no RTS is used a manual power toggle is needed
+	 
+#### Minimal hardware Setup for running only ####
+
+ESPxx Hardware
+
+| PIN           | Resistor | Power supply    |
+| ------------- | -------- | --------------- | 
+| VCC           |          | VCC (3.3V)      |
+| GND           |          | GND             |
+| GPIO0         | PullUp   |                 |
+| GPIO15        | PullDown |                 |
+| CH_PD         | PullUp   |                 |
+
+###### minimal
+![ESP min](https://raw.githubusercontent.com/Links2004/Arduino/esp8266/docs/ESP_min.png)
+
+###### improved stability
+![ESP improved stability](https://raw.githubusercontent.com/Links2004/Arduino/esp8266/docs/ESP_improved_stability.png)	
 
 ### Issues and support ###
 

doc/ESP_improved_stability.png

@@ -46,6 +46,9 @@ ESP8266WiFiClass::ESP8266WiFiClass()
 
 void ESP8266WiFiClass::mode(WiFiMode m)
 {
+    if(wifi_get_opmode() == (uint8)m) {
+        return;
+    }
     ETS_UART_INTR_DISABLE();
     wifi_set_opmode(m);
     ETS_UART_INTR_ENABLE();
@@ -357,10 +360,14 @@ void ESP8266WiFiClass::_scanDone(void* result, int status)
 
 int8_t ESP8266WiFiClass::scanNetworks()
 {
-    if ((wifi_get_opmode() & 1) == 0)//1 and 3 have STA enabled
-    {
+    if(_useApMode) {
+        // turn on AP+STA mode
         mode(WIFI_AP_STA);
+    } else {
+        // turn on STA mode
+        mode(WIFI_STA);
     }
+
     int status = wifi_station_get_connect_status();
     if (status != STATION_GOT_IP && status != STATION_IDLE)
     {
@@ -532,9 +539,12 @@ void ESP8266WiFiClass::beginSmartConfig()
     if (_smartConfigStarted)
         return;
 
-    if ((wifi_get_opmode() & 1) == 0)//1 and 3 have STA enabled
-    {
+    if(_useApMode) {
+        // turn on AP+STA mode
         mode(WIFI_AP_STA);
+    } else {
+        // turn on STA mode
+        mode(WIFI_STA);
     }
 
     _smartConfigStarted = true;

doc/ESP_min.png

@@ -72,7 +72,6 @@ wl_status_t ESP8266WiFiMulti::run(void) {
 
                 WiFi.getNetworkInfo(i, ssid_scan, sec_scan, rssi_scan, BSSID_scan, chan_scan, hidden_scan);
 
-
                 bool known = false;
                 for(uint32_t x = 0; x < APlist.size(); x++) {
                     WifiAPlist_t entry = APlist[x];
@@ -152,7 +151,17 @@ bool ESP8266WiFiMulti::APlistAdd(const char* ssid, const char *passphrase) {
 
     WifiAPlist_t newAP;
 
-    newAP.ssid = (char*) malloc(strlen(ssid));
+    if(!ssid || strlen(ssid) > 31) {
+        // fail SSID to long or missing!
+        return false;
+    }
+
+    if(passphrase && strlen(passphrase) > 63) {
+        // fail passphrase to long!
+        return false;
+    }
+
+    newAP.ssid = (char*) malloc((strlen(ssid) + 1));
 
     if(!newAP.ssid) {
         return false;
@@ -161,16 +170,14 @@ bool ESP8266WiFiMulti::APlistAdd(const char* ssid, const char *passphrase) {
     strcpy(newAP.ssid, ssid);
 
     if(passphrase && *passphrase != 0x00) {
-        newAP.passphrase = (char*) malloc(strlen(passphrase));
-    }
-
-    if(!newAP.passphrase) {
-        free(newAP.ssid);
-        return false;
+        newAP.passphrase = (char*) malloc((strlen(passphrase) + 1));
+        if(!newAP.passphrase) {
+            free(newAP.ssid);
+            return false;
+        }
+        strcpy(newAP.passphrase, passphrase);
     }
 
-    strcpy(newAP.passphrase, passphrase);
-
     APlist.push_back(newAP);
     return true;
 }