Merge pull request #8959 from VeijoPesonen/feature-esp8266_reset_pin

0xc0170 · web-flow · commit 08d11277296f · 2018-12-11T15:37:10.000+01:00
[ESP8266] Adds support for controlling HW reset of the modem from the…
diff --git a/components/wifi/esp8266-driver/ESP8266/ESP8266.cpp b/components/wifi/esp8266-driver/ESP8266/ESP8266.cpp
@@ -91,9 +91,18 @@ ESP8266::ESP8266(PinName tx, PinName rx, bool debug, PinName rts, PinName cts)
 
 bool ESP8266::at_available()
 {
+    bool ready = false;
+
     _smutex.lock();
-    bool ready = _parser.send("AT")
-                 && _parser.recv("OK\n");
+    // Might take a while to respond after HW reset
+    for(int i = 0; i < 5; i++) {
+        ready = _parser.send("AT")
+                && _parser.recv("OK\n");
+        if (ready) {
+            break;
+        }
+        tr_debug("waiting AT response");
+    }
     _smutex.unlock();
 
     return ready;
@@ -224,22 +233,25 @@ bool ESP8266::startup(int mode)
 
 bool ESP8266::reset(void)
 {
+    bool done = false;
+
     _smutex.lock();
     set_timeout(ESP8266_CONNECT_TIMEOUT);
 
     for (int i = 0; i < 2; i++) {
         if (_parser.send("AT+RST")
                 && _parser.recv("OK\n")
                 && _parser.recv("ready")) {
-            _clear_socket_packets(ESP8266_ALL_SOCKET_IDS);
-            _smutex.unlock();
-            return true;
+            done = true;
+            break;
         }
     }
+
+    _clear_socket_packets(ESP8266_ALL_SOCKET_IDS);
     set_timeout();
     _smutex.unlock();
 
-    return false;
+    return done;
 }
 
 bool ESP8266::dhcp(bool enabled, int mode)
@@ -276,14 +288,14 @@ bool ESP8266::cond_enable_tcp_passive_mode()
 
 nsapi_error_t ESP8266::connect(const char *ap, const char *passPhrase)
 {
+    nsapi_error_t ret = NSAPI_ERROR_OK;
+
     _smutex.lock();
     set_timeout(ESP8266_CONNECT_TIMEOUT);
 
     _parser.send("AT+CWJAP_CUR=\"%s\",\"%s\"", ap, passPhrase);
     if (!_parser.recv("OK\n")) {
         if (_fail) {
-            _smutex.unlock();
-            nsapi_error_t ret;
             if (_connect_error == 1) {
                 ret = NSAPI_ERROR_CONNECTION_TIMEOUT;
             } else if (_connect_error == 2) {
@@ -293,16 +305,15 @@ nsapi_error_t ESP8266::connect(const char *ap, const char *passPhrase)
             } else {
                 ret = NSAPI_ERROR_NO_CONNECTION;
             }
-
             _fail = false;
             _connect_error = 0;
-            return ret;
         }
     }
+
     set_timeout();
     _smutex.unlock();
 
-    return NSAPI_ERROR_OK;
+    return ret;
 }
 
 bool ESP8266::disconnect(void)
diff --git a/components/wifi/esp8266-driver/ESP8266Interface.cpp b/components/wifi/esp8266-driver/ESP8266Interface.cpp
@@ -27,6 +27,7 @@
 #include "mbed_trace.h"
 #include "platform/Callback.h"
 #include "platform/mbed_debug.h"
+#include "platform/mbed_wait_api.h"
 
 #ifndef MBED_CONF_ESP8266_DEBUG
 #define MBED_CONF_ESP8266_DEBUG false
@@ -40,16 +41,20 @@
 #define MBED_CONF_ESP8266_CTS NC
 #endif
 
+#ifndef MBED_CONF_ESP8266_RST
+#define MBED_CONF_ESP8266_RST NC
+#endif
+
 #define TRACE_GROUP  "ESPI" // ESP8266 Interface
 
 using namespace mbed;
 
 #if defined MBED_CONF_ESP8266_TX && defined MBED_CONF_ESP8266_RX
 ESP8266Interface::ESP8266Interface()
     : _esp(MBED_CONF_ESP8266_TX, MBED_CONF_ESP8266_RX, MBED_CONF_ESP8266_DEBUG, MBED_CONF_ESP8266_RTS, MBED_CONF_ESP8266_CTS),
+      _rst_pin(MBED_CONF_ESP8266_RST), // Notice that Pin7 CH_EN cannot be left floating if used as reset
       _ap_sec(NSAPI_SECURITY_UNKNOWN),
       _initialized(false),
-      _started(false),
       _conn_stat(NSAPI_STATUS_DISCONNECTED),
       _conn_stat_cb(NULL),
       _global_event_queue(NULL),
@@ -67,15 +72,17 @@ ESP8266Interface::ESP8266Interface()
         _sock_i[i].open = false;
         _sock_i[i].sport = 0;
     }
+
+    _oob2global_event_queue();
 }
 #endif
 
 // ESP8266Interface implementation
-ESP8266Interface::ESP8266Interface(PinName tx, PinName rx, bool debug, PinName rts, PinName cts)
+ESP8266Interface::ESP8266Interface(PinName tx, PinName rx, bool debug, PinName rts, PinName cts, PinName rst)
     : _esp(tx, rx, debug, rts, cts),
+      _rst_pin(rst),
       _ap_sec(NSAPI_SECURITY_UNKNOWN),
       _initialized(false),
-      _started(false),
       _conn_stat(NSAPI_STATUS_DISCONNECTED),
       _conn_stat_cb(NULL),
       _global_event_queue(NULL),
@@ -93,13 +100,44 @@ ESP8266Interface::ESP8266Interface(PinName tx, PinName rx, bool debug, PinName r
         _sock_i[i].open = false;
         _sock_i[i].sport = 0;
     }
+
+    _oob2global_event_queue();
 }
 
 ESP8266Interface::~ESP8266Interface()
 {
     if (_oob_event_id) {
         _global_event_queue->cancel(_oob_event_id);
     }
+
+    // Power down the modem
+    _rst_pin.rst_assert();
+}
+
+ESP8266Interface::ResetPin::ResetPin(PinName rst_pin) : _rst_pin(mbed::DigitalOut(rst_pin, 1))
+{
+}
+
+void ESP8266Interface::ResetPin::rst_assert()
+{
+    if (_rst_pin.is_connected()) {
+        _rst_pin = 0;
+        tr_debug("HW reset asserted");
+    }
+}
+
+void ESP8266Interface::ResetPin::rst_deassert()
+{
+    if (_rst_pin.is_connected()) {
+        // Notice that Pin7 CH_EN cannot be left floating if used as reset
+        _rst_pin = 1;
+        tr_debug("HW reset deasserted");
+    }
+}
+
+bool ESP8266Interface::ResetPin::is_connected()
+{
+    return _rst_pin.is_connected();
 }
 
 int ESP8266Interface::connect(const char *ssid, const char *pass, nsapi_security_t security,
@@ -147,10 +185,6 @@ int ESP8266Interface::connect()
         return status;
     }
 
-    if (!_oob_event_id) {
-        _oob2global_event_queue();
-    }
-
     if (get_ip_address()) {
         return NSAPI_ERROR_IS_CONNECTED;
     }
@@ -159,22 +193,12 @@ int ESP8266Interface::connect()
     if (status != NSAPI_ERROR_OK) {
         return status;
     }
-    _started = true;
 
     if (!_esp.dhcp(true, 1)) {
         return NSAPI_ERROR_DHCP_FAILURE;
     }
 
-    int connect_error = _esp.connect(ap_ssid, ap_pass);
-    if (connect_error) {
-        return connect_error;
-    }
-
-    if (!get_ip_address()) {
-        return NSAPI_ERROR_DHCP_FAILURE;
-    }
-
-    return NSAPI_ERROR_OK;
+    return _esp.connect(ap_ssid, ap_pass);
 }
 
 int ESP8266Interface::set_credentials(const char *ssid, const char *pass, nsapi_security_t security)
@@ -224,6 +248,8 @@ int ESP8266Interface::set_channel(uint8_t channel)
 
 int ESP8266Interface::disconnect()
 {
+    _initialized = false;
+
     if (_conn_stat == NSAPI_STATUS_DISCONNECTED)
     {
         return NSAPI_ERROR_NO_CONNECTION;
@@ -234,19 +260,23 @@ int ESP8266Interface::disconnect()
     if (ret == NSAPI_ERROR_OK) {
         // Try to lure the nw status update from ESP8266, might come later
         _esp.bg_process_oob(ESP8266_RECV_TIMEOUT, true);
-        // In case the status update arrives later
-        _conn_stat = NSAPI_STATUS_DISCONNECTED;
+        // In case the status update arrives later inform upper layers manually
+        if (_conn_stat != NSAPI_STATUS_DISCONNECTED) {
+            _conn_stat = NSAPI_STATUS_DISCONNECTED;
+            if (_conn_stat_cb) {
+                _conn_stat_cb(NSAPI_EVENT_CONNECTION_STATUS_CHANGE, _conn_stat);
+            }
+        }
     }
 
+    // Power down the modem
+    _rst_pin.rst_assert();
+
     return ret;
 }
 
 const char *ESP8266Interface::get_ip_address()
 {
-    if (!_started) {
-        return NULL;
-    }
-
     const char *ip_buff = _esp.ip_addr();
     if (!ip_buff || strcmp(ip_buff, "0.0.0.0") == 0) {
         return NULL;
@@ -262,17 +292,17 @@ const char *ESP8266Interface::get_mac_address()
 
 const char *ESP8266Interface::get_gateway()
 {
-    return _started ? _esp.gateway() : NULL;
+    return _conn_stat != NSAPI_STATUS_DISCONNECTED ? _esp.gateway() : NULL;
 }
 
 const char *ESP8266Interface::get_netmask()
 {
-    return _started ? _esp.netmask() : NULL;
+    return _conn_stat != NSAPI_STATUS_DISCONNECTED ? _esp.netmask() : NULL;
 }
 
 int8_t ESP8266Interface::get_rssi()
 {
-    return _started ? _esp.rssi() : 0;
+    return _esp.rssi();
 }
 
 int ESP8266Interface::scan(WiFiAccessPoint *res, unsigned count)
@@ -313,6 +343,8 @@ bool ESP8266Interface::_get_firmware_ok()
 nsapi_error_t ESP8266Interface::_init(void)
 {
     if (!_initialized) {
+        _hw_reset();
+
         if (!_esp.at_available()) {
             return NSAPI_ERROR_DEVICE_ERROR;
         }
@@ -343,9 +375,18 @@ nsapi_error_t ESP8266Interface::_init(void)
     return NSAPI_ERROR_OK;
 }
 
+void ESP8266Interface::_hw_reset()
+{
+    _rst_pin.rst_assert();
+    // If you happen to use Pin7 CH_EN as reset pin, not needed otherwise
+    // https://www.espressif.com/sites/default/files/documentation/esp8266_hardware_design_guidelines_en.pdf
+    wait_us(200);
+    _rst_pin.rst_deassert();
+}
+
 nsapi_error_t ESP8266Interface::_startup(const int8_t wifi_mode)
 {
-    if (!_started) {
+    if (_conn_stat == NSAPI_STATUS_DISCONNECTED) {
         if (!_esp.startup(wifi_mode)) {
             return NSAPI_ERROR_DEVICE_ERROR;
         }
@@ -646,25 +687,26 @@ WiFiInterface *WiFiInterface::get_default_instance()
 
 void ESP8266Interface::update_conn_state_cb()
 {
+    nsapi_connection_status_t prev_stat = _conn_stat;
     _conn_stat = _esp.connection_status();
 
+    if (prev_stat == _conn_stat) {
+        return;
+    }
+
     switch (_conn_stat) {
         // Doesn't require changes
         case NSAPI_STATUS_CONNECTING:
         case NSAPI_STATUS_GLOBAL_UP:
             break;
         // Start from scratch if connection drops/is dropped
         case NSAPI_STATUS_DISCONNECTED:
-            _started = false;
             break;
         // Handled on AT layer
         case NSAPI_STATUS_LOCAL_UP:
         case NSAPI_STATUS_ERROR_UNSUPPORTED:
         default:
-            _started = false;
             _initialized = false;
-            _global_event_queue->cancel(_oob_event_id);
-            _oob_event_id = 0;
             _conn_stat = NSAPI_STATUS_DISCONNECTED;
     }
 
@@ -676,8 +718,6 @@ void ESP8266Interface::update_conn_state_cb()
 
 void ESP8266Interface::proc_oob_evnt()
 {
-    if (_initialized) {
         _esp.bg_process_oob(ESP8266_RECV_TIMEOUT, true);
-    }
 }
 #endif
diff --git a/components/wifi/esp8266-driver/ESP8266Interface.h b/components/wifi/esp8266-driver/ESP8266Interface.h
@@ -18,6 +18,7 @@
 #define ESP8266_INTERFACE_H
 
 #if DEVICE_SERIAL && defined(MBED_CONF_EVENTS_PRESENT) && defined(MBED_CONF_NSAPI_PRESENT) && defined(MBED_CONF_RTOS_PRESENT)
+#include "drivers/DigitalOut.h"
 #include "ESP8266/ESP8266.h"
 #include "events/EventQueue.h"
 #include "events/mbed_shared_queues.h"
@@ -59,7 +60,7 @@ class ESP8266Interface : public NetworkStack, public WiFiInterface {
      * @param rx        RX pin
      * @param debug     Enable debugging
      */
-    ESP8266Interface(PinName tx, PinName rx, bool debug = false, PinName rts = NC, PinName cts = NC);
+    ESP8266Interface(PinName tx, PinName rx, bool debug = false, PinName rts = NC, PinName cts = NC, PinName rst = NC);
 
     /**
      * @brief ESP8266Interface default destructor
@@ -320,6 +321,18 @@ class ESP8266Interface : public NetworkStack, public WiFiInterface {
     ESP8266 _esp;
     void update_conn_state_cb();
 
+    // HW reset pin
+    class ResetPin {
+    public:
+        ResetPin(PinName rst_pin);
+        void rst_assert();
+        void rst_deassert();
+        bool is_connected();
+    private:
+        mbed::DigitalOut  _rst_pin;
+    } _rst_pin;
+
+
     // Credentials
     static const int ESP8266_SSID_MAX_LENGTH = 32; /* 32 is what 802.11 defines as longest possible name */
     char ap_ssid[ESP8266_SSID_MAX_LENGTH + 1]; /* The longest possible name; +1 for the \0 */
@@ -339,7 +352,7 @@ class ESP8266Interface : public NetworkStack, public WiFiInterface {
     int _initialized;
     bool _get_firmware_ok();
     nsapi_error_t _init(void);
-    int _started;
+    void _hw_reset();
     nsapi_error_t _startup(const int8_t wifi_mode);
 
     //sigio
diff --git a/components/wifi/esp8266-driver/mbed_lib.json b/components/wifi/esp8266-driver/mbed_lib.json
