add NRF52 BLE example code

docs/software/nrf52-TODO.md

@@ -1,12 +1,26 @@
+# Initial work items
 
-* make a new boarddef with a variant.h file.  Fix pins in that file.  In particular:
+- get old radio driver working on NRF52
-#define PIN_SPI_MISO         (46)
+- get BLE working
-#define PIN_SPI_MOSI         (45)
+- add PMU driver
-#define PIN_SPI_SCK          (47)
+- add new radio driver
-#define PIN_WIRE_SDA         (26)
+- make a file system implementation (preferably one that can see the files the bootloader also sees)
-#define PIN_WIRE_SCL         (27)
+- add LCD driver
+- make a new boarddef with a variant.h file. Fix pins in that file. In particular:
+  #define PIN_SPI_MISO (46)
+  #define PIN_SPI_MOSI (45)
+  #define PIN_SPI_SCK (47)
+  #define PIN_WIRE_SDA (26)
+  #define PIN_WIRE_SCL (27)
 
+# Secondary work items
 
+- turn on security for BLE
+- make power management/sleep work properly
+- make a settimeofday implementation
+- make ble endpoints not require "start config", jsut have them start in config mode
+
+```
 /*
 per
 https://docs.platformio.org/en/latest/tutorials/nordicnrf52/arduino_debugging_unit_testing.html
@@ -57,3 +71,4 @@ https://learn.adafruit.com/bluefruit-nrf52-feather-learning-guide/custom-hrm
 good led ble demo:
 https://github.com/adafruit/Adafruit_nRF52_Arduino/blob/master/libraries/Bluefruit52Lib/examples/Peripheral/nrf_blinky/nrf_blinky.ino
 */
+```

src/bare/NRF52Bluetooth.cpp

@@ -0,0 +1,206 @@
+#include "NRF52Bluetooth.h"
+#include "configuration.h"
+#include <bluefruit.h>
+
+/* HRM Service Definitions
+ * Heart Rate Monitor Service:  0x180D
+ * Heart Rate Measurement Char: 0x2A37
+ * Body Sensor Location Char:   0x2A38
+ */
+BLEService hrms = BLEService(UUID16_SVC_HEART_RATE);
+BLECharacteristic hrmc = BLECharacteristic(UUID16_CHR_HEART_RATE_MEASUREMENT);
+BLECharacteristic bslc = BLECharacteristic(UUID16_CHR_BODY_SENSOR_LOCATION);
+
+BLEDis bledis; // DIS (Device Information Service) helper class instance
+BLEBas blebas; // BAS (Battery Service) helper class instance
+
+uint8_t bps = 0;
+
+void connect_callback(uint16_t conn_handle)
+{
+    // Get the reference to current connection
+    BLEConnection *connection = Bluefruit.Connection(conn_handle);
+
+    char central_name[32] = {0};
+    connection->getPeerName(central_name, sizeof(central_name));
+
+    DEBUG_MSG("Connected to %s\n", central_name);
+}
+
+/**
+ * Callback invoked when a connection is dropped
+ * @param conn_handle connection where this event happens
+ * @param reason is a BLE_HCI_STATUS_CODE which can be found in ble_hci.h
+ */
+void disconnect_callback(uint16_t conn_handle, uint8_t reason)
+{
+    (void)conn_handle;
+    (void)reason;
+
+    DEBUG_MSG("Disconnected, reason = 0x%x\n", reason);
+}
+
+void cccd_callback(uint16_t conn_hdl, BLECharacteristic *chr, uint16_t cccd_value)
+{
+    // Display the raw request packet
+    DEBUG_MSG("CCCD Updated: %u\n", cccd_value);
+
+    // Check the characteristic this CCCD update is associated with in case
+    // this handler is used for multiple CCCD records.
+    if (chr->uuid == hrmc.uuid) {
+        if (chr->notifyEnabled(conn_hdl)) {
+            DEBUG_MSG("Heart Rate Measurement 'Notify' enabled\n");
+        } else {
+            DEBUG_MSG("Heart Rate Measurement 'Notify' disabled\n");
+        }
+    }
+}
+
+void startAdv(void)
+{
+    // Advertising packet
+    Bluefruit.Advertising.addFlags(BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE);
+    Bluefruit.Advertising.addTxPower();
+
+    // Include HRM Service UUID
+    Bluefruit.Advertising.addService(hrms);
+
+    // Include Name
+    Bluefruit.Advertising.addName();
+
+    /* Start Advertising
+     * - Enable auto advertising if disconnected
+     * - Interval:  fast mode = 20 ms, slow mode = 152.5 ms
+     * - Timeout for fast mode is 30 seconds
+     * - Start(timeout) with timeout = 0 will advertise forever (until connected)
+     *
+     * For recommended advertising interval
+     * https://developer.apple.com/library/content/qa/qa1931/_index.html
+     */
+    Bluefruit.Advertising.restartOnDisconnect(true);
+    Bluefruit.Advertising.setInterval(32, 244); // in unit of 0.625 ms
+    Bluefruit.Advertising.setFastTimeout(30);   // number of seconds in fast mode
+    Bluefruit.Advertising.start(0);             // 0 = Don't stop advertising after n seconds
+}
+
+void setupHRM(void)
+{
+    // Configure the Heart Rate Monitor service
+    // See: https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.service.heart_rate.xml
+    // Supported Characteristics:
+    // Name                         UUID    Requirement Properties
+    // ---------------------------- ------  ----------- ----------
+    // Heart Rate Measurement       0x2A37  Mandatory   Notify
+    // Body Sensor Location         0x2A38  Optional    Read
+    // Heart Rate Control Point     0x2A39  Conditional Write       <-- Not used here
+    hrms.begin();
+
+    // Note: You must call .begin() on the BLEService before calling .begin() on
+    // any characteristic(s) within that service definition.. Calling .begin() on
+    // a BLECharacteristic will cause it to be added to the last BLEService that
+    // was 'begin()'ed!
+
+    // Configure the Heart Rate Measurement characteristic
+    // See:
+    // https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.characteristic.heart_rate_measurement.xml
+    // Properties = Notify
+    // Min Len    = 1
+    // Max Len    = 8
+    //    B0      = UINT8  - Flag (MANDATORY)
+    //      b5:7  = Reserved
+    //      b4    = RR-Internal (0 = Not present, 1 = Present)
+    //      b3    = Energy expended status (0 = Not present, 1 = Present)
+    //      b1:2  = Sensor contact status (0+1 = Not supported, 2 = Supported but contact not detected, 3 = Supported and
+    //      detected) b0    = Value format (0 = UINT8, 1 = UINT16)
+    //    B1      = UINT8  - 8-bit heart rate measurement value in BPM
+    //    B2:3    = UINT16 - 16-bit heart rate measurement value in BPM
+    //    B4:5    = UINT16 - Energy expended in joules
+    //    B6:7    = UINT16 - RR Internal (1/1024 second resolution)
+    hrmc.setProperties(CHR_PROPS_NOTIFY);
+    hrmc.setPermission(SECMODE_OPEN, SECMODE_NO_ACCESS);
+    hrmc.setFixedLen(2);
+    hrmc.setCccdWriteCallback(cccd_callback); // Optionally capture CCCD updates
+    hrmc.begin();
+    uint8_t hrmdata[2] = {0b00000110, 0x40}; // Set the characteristic to use 8-bit values, with the sensor connected and detected
+    hrmc.write(hrmdata, 2);
+
+    // Configure the Body Sensor Location characteristic
+    // See:
+    // https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.characteristic.body_sensor_location.xml
+    // Properties = Read
+    // Min Len    = 1
+    // Max Len    = 1
+    //    B0      = UINT8 - Body Sensor Location
+    //      0     = Other
+    //      1     = Chest
+    //      2     = Wrist
+    //      3     = Finger
+    //      4     = Hand
+    //      5     = Ear Lobe
+    //      6     = Foot
+    //      7:255 = Reserved
+    bslc.setProperties(CHR_PROPS_READ);
+    bslc.setPermission(SECMODE_OPEN, SECMODE_NO_ACCESS);
+    bslc.setFixedLen(1);
+    bslc.begin();
+    bslc.write8(2); // Set the characteristic to 'Wrist' (2)
+}
+
+void NRF52Bluetooth::setup()
+{
+    // Initialise the Bluefruit module
+    DEBUG_MSG("Initialise the Bluefruit nRF52 module\n");
+    Bluefruit.begin();
+
+    // Set the advertised device name (keep it short!)
+    Bluefruit.setName("Meshtastic52");
+
+    // Set the connect/disconnect callback handlers
+    Bluefruit.Periph.setConnectCallback(connect_callback);
+    Bluefruit.Periph.setDisconnectCallback(disconnect_callback);
+
+    // Configure and Start the Device Information Service
+    DEBUG_MSG("Configuring the Device Information Service");
+    bledis.setManufacturer("meshtastic.org");
+    bledis.setModel("NRF52-meshtastic");
+    bledis.begin();
+
+    // Start the BLE Battery Service and set it to 100%
+    DEBUG_MSG("Configuring the Battery Service");
+    blebas.begin();
+    blebas.write(42); // FIXME, report real power levels
+
+    // Setup the Heart Rate Monitor service using
+    // BLEService and BLECharacteristic classes
+    DEBUG_MSG("Configuring the Heart Rate Monitor Service");
+    setupHRM();
+
+    // Setup the advertising packet(s)
+    DEBUG_MSG("Setting up the advertising payload(s)\n");
+    startAdv();
+
+    DEBUG_MSG("Advertising\n");
+}
+
+/*
+void loop()
+{
+  digitalToggle(LED_RED);
+
+  if ( Bluefruit.connected() ) {
+    uint8_t hrmdata[2] = { 0b00000110, bps++ };           // Sensor connected, increment BPS value
+
+    // Note: We use .notify instead of .write!
+    // If it is connected but CCCD is not enabled
+    // The characteristic's value is still updated although notification is not sent
+    if ( hrmc.notify(hrmdata, sizeof(hrmdata)) ){
+      Serial.print("Heart Rate Measurement updated to: "); Serial.println(bps);
+    }else{
+      Serial.println("ERROR: Notify not set in the CCCD or not connected!");
+    }
+  }
+
+  // Only send update once per second
+  delay(1000);
+}
+*/

src/bare/NRF52Bluetooth.h

@@ -0,0 +1,8 @@
+#pragma once
+
+class NRF52Bluetooth
+{
+  public:
+    void setup();
+};
+

src/bare/main-bare.cpp

@@ -1,7 +1,2 @@
 #include "target_specific.h"
 
-void setBluetoothEnable(bool on)
-{
-    // Do nothing
-}
-

src/bare/main-nrf52.cpp

@@ -1,3 +1,5 @@
+#include "NRF52Bluetooth.h"
+#include "configuration.h"
 #include <assert.h>
 #include <ble_gap.h>
 #include <memory.h>
@@ -32,3 +34,21 @@ void getMacAddr(uint8_t *dmac)
     memcpy(dmac, (const void *)NRF_FICR->DEVICEADDR, 6);
 #endif
 }
+
+NRF52Bluetooth *nrf52Bluetooth;
+
+static bool bleOn = false;
+void setBluetoothEnable(bool on)
+{
+    if (on != bleOn) {
+        if (on) {
+            if (!nrf52Bluetooth) {
+                nrf52Bluetooth = new NRF52Bluetooth();
+                nrf52Bluetooth->setup();
+            }
+        } else {
+            DEBUG_MSG("FIXME: implement BLE disable\n");
+        }
+        bleOn = on;
+    }
+}