Diff: main.cpp

Revision:

0:9e78d3dbb29d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sun Jan 04 17:10:18 2015 +0000
@@ -0,0 +1,112 @@
+//==============================================================================
+// This code shows a problem that occurs when a Ticker is used on the nrf51822
+// along with a BLEDevice. The ticker hangs after a while if the timeout is
+// short enough (around 1ms or less, with 2ms or more being OK). The same ticker
+// works fine if no BLE device is created. The bug was confirmed on both a
+// Nordic nRF51-Dongle and a RedBearLab BLE Nano using the latest BLE_API,
+// mbed-src and nRF51822 libraries as of Jan 3rd 2015.
+//==============================================================================
+// My unconfirmed wild guess is that the bug may be somewhere in
+// mbed-src/targets/hal/TARGET_NORDIC/TARGET_MCU_NRF51822/Lib/app_common/app_timer.c
+// and may be triggered by the BLE stack interrupts delaying the Ticker beyond
+// its next timeout.
+//==============================================================================
+// This code blinks the onboard LED 5 times per second via a 1ms ticker that
+// switches the LED state once every 100 invocations.
+// When BLE support is enabled, the LED blinks a few times and then stops.
+// When BLE support is disabled, the LED keeps blinking forever.
+//==============================================================================
+// Set this to 1 to enable BLE support and trigger the Ticker bug, or 0 to fix
+
+#define ENABLE_BLE_AND_BUG 1
+
+//==============================================================================
+
+#include "mbed.h"
+#include "nrf_soc.h"
+#include "BLEDevice.h"
+
+//==============================================================================
+#if ENABLE_BLE_AND_BUG
+//==============================================================================
+
+#define BUFFER_LENGTH 20
+
+static const uint8_t uart_base_uuid[]       = {0x71, 0x3D, 0, 0, 0x50, 0x3E, 0x4C, 0x75, 0xBA, 0x94, 0x31, 0x48, 0xF1, 0x8D, 0x94, 0x1E};
+static const uint8_t uart_tx_uuid[]         = {0x71, 0x3D, 0, 3, 0x50, 0x3E, 0x4C, 0x75, 0xBA, 0x94, 0x31, 0x48, 0xF1, 0x8D, 0x94, 0x1E};
+static const uint8_t uart_rx_uuid[]         = {0x71, 0x3D, 0, 2, 0x50, 0x3E, 0x4C, 0x75, 0xBA, 0x94, 0x31, 0x48, 0xF1, 0x8D, 0x94, 0x1E};
+static const uint8_t uart_base_uuid_rev[]   = {0x1E, 0x94, 0x8D, 0xF1, 0x48, 0x31, 0x94, 0xBA, 0x75, 0x4C, 0x3E, 0x50, 0, 0, 0x3D, 0x71};
+
+static uint8_t txPayload[BUFFER_LENGTH] = {0,};
+static uint8_t rxPayload[BUFFER_LENGTH] = {0,};
+
+GattCharacteristic  txCharacteristic(uart_tx_uuid, txPayload, 1, BUFFER_LENGTH, GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_WRITE | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_WRITE_WITHOUT_RESPONSE);
+GattCharacteristic  rxCharacteristic(uart_rx_uuid, rxPayload, 1, BUFFER_LENGTH, GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY);
+GattCharacteristic  *uartChars[] = {&txCharacteristic, &rxCharacteristic};
+GattService         uartService(uart_base_uuid, uartChars, sizeof(uartChars) / sizeof(GattCharacteristic*));
+
+BLEDevice   ble;
+
+//==============================================================================
+
+static void handleDisconnect(Gap::Handle_t handle, Gap::DisconnectionReason_t reason)
+{
+    ble.startAdvertising();
+}
+
+//==============================================================================
+
+static void handleReceivedData(const GattCharacteristicWriteCBParams *Handler)
+{   
+    // we don't look at incoming data
+}
+
+//==============================================================================
+#endif // ENABLE_BLE_AND_BUG
+//==============================================================================
+
+Ticker      testTicker;
+DigitalOut  testLed(LED1);
+int         testLedState    = 0;
+uint32_t    testLedCount    = 0;
+
+//==============================================================================
+
+static void periodicTask(void)
+{
+    if(++testLedCount >= 100)
+    {
+        testLedCount = 0;
+        if(++testLedState > 1) testLedState = 0;
+        testLed = testLedState;
+    }
+}
+
+//==============================================================================
+
+int main(void)
+{
+#if ENABLE_BLE_AND_BUG
+    ble.init();
+    ble.onDisconnection(handleDisconnect);
+    ble.onDataWritten(handleReceivedData);  
+    ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED);
+    ble.setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED);
+    ble.accumulateAdvertisingPayload(GapAdvertisingData::SHORTENED_LOCAL_NAME, (const uint8_t*)"Buggy", sizeof("Buggy") - 1);
+    ble.accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_128BIT_SERVICE_IDS, (const uint8_t *)uart_base_uuid_rev, 16);
+    ble.setAdvertisingInterval(160);
+    ble.addService(uartService);
+    ble.startAdvertising();
+#endif
+    
+    testTicker.attach_us(periodicTask, 1000);
+    
+    while(1)
+    {
+#if ENABLE_BLE_AND_BUG
+        ble.waitForEvent();
+#endif
+    }
+}
+
+//==============================================================================