Initial commit.

9 files changed, 305 insertions, 0 deletions

diff --git a/nrf52/Makefile b/nrf52/Makefile
new file mode 100644
index 0000000..fdb47ee
--- /dev/null
+++ b/nrf52/Makefile
@@ -0,0 +1,22 @@
+include ../Makefile.common
+#include Makefile.feather-52840
+include Makefile.feather-52832
+
+SERIALPORT = $(shell ../find-serial-port $(USBVID) $(USBPID) || echo 'cant-find-serial-port')
+
+APP = nrf52
+
+all: $(BUILDDIR)/$(APP).ino.zip
+
+flash: $(BUILDDIR)/$(APP).ino.zip $(SERIALPORT)
+	adafruit-nrfutil dfu serial --package $(BUILDDIR)/$(APP).ino.zip -p $(SERIALPORT) -b 115200 -sb -t 1200
+
+console:
+	screen $(SERIALPORT) 115200
+
+# Deps
+nrf52.ino: i2c_ring_buffer.cpp state_machine.cpp log.h ../common/i2c_message.h
+
+i2c_ring_buffer.cpp: i2c_ring_buffer.h
+
+state_machine.cpp: state_machine.h
diff --git a/nrf52/Makefile.feather-52832 b/nrf52/Makefile.feather-52832
new file mode 100644
index 0000000..c2dff2b
--- /dev/null
+++ b/nrf52/Makefile.feather-52832
@@ -0,0 +1,10 @@
+# -*- mode: Makefile -*-
+
+VENDOR = adafruit
+PLATFORM = nrf52
+BOARD = feather52832
+
+EXTRAPREFS = -prefs "build.sd_flags=-DS132" -prefs "build.sd_name=s132" -prefs "build.sd_version=6.1.1" -prefs "build.sd_fwid=0x00B7"
+
+USBVID = 10c4
+USBPID = ea60
diff --git a/nrf52/Makefile.feather-52840 b/nrf52/Makefile.feather-52840
new file mode 100644
index 0000000..81d7245
--- /dev/null
+++ b/nrf52/Makefile.feather-52840
@@ -0,0 +1,10 @@
+# -*- mode: Makefile -*-
+
+VENDOR = adafruit
+PLATFORM = nrf52
+BOARD = feather52840
+
+EXTRAPREFS = -prefs "build.sd_name=s140" -prefs "build.sd_version=6.1.1" -prefs "build.sd_fwid=0x00B6"
+
+USBVID = 239a
+USBPID = '0029|8029'
diff --git a/nrf52/i2c_ring_buffer.cpp b/nrf52/i2c_ring_buffer.cpp
new file mode 100644
index 0000000..0f215f2
--- /dev/null
+++ b/nrf52/i2c_ring_buffer.cpp
@@ -0,0 +1,24 @@
+#include "i2c_ring_buffer.h"
+
+#include <SimplyAtomic.h>
+
+I2CRingBuffer::I2CRingBuffer(): head(0), tail(0) {}
+
+bool I2CRingBuffer::read(uint8_t *v) {
+  ATOMIC() {
+    if (this->head == this->tail) {
+      return false;
+    }
+
+    *v = this->buf[this->head];
+    this->head = (this->head + 1) % RINGBUFLEN;
+    return true;
+  }
+}
+
+void I2CRingBuffer::write(uint8_t v) {
+  ATOMIC() {
+    this->buf[this->tail] = v;
+    this->tail = (this->tail + 1) % RINGBUFLEN;
+  }
+}
diff --git a/nrf52/i2c_ring_buffer.h b/nrf52/i2c_ring_buffer.h
new file mode 100644
index 0000000..a274798
--- /dev/null
+++ b/nrf52/i2c_ring_buffer.h
@@ -0,0 +1,21 @@
+#ifndef I2C_RING_BUFFER_H
+#define I2C_RING_BUFFER_H
+
+#include <stdint.h>
+
+#define RINGBUFLEN 256
+
+class I2CRingBuffer {
+public:
+  I2CRingBuffer();
+
+  bool read(uint8_t *);
+  void write(uint8_t);
+
+private:
+  volatile uint8_t buf[RINGBUFLEN];
+  volatile uint8_t head;
+  volatile uint8_t tail;
+};
+
+#endif
diff --git a/nrf52/log.h b/nrf52/log.h
new file mode 100644
index 0000000..b78fec0
--- /dev/null
+++ b/nrf52/log.h
@@ -0,0 +1,17 @@
+#ifndef LOG_H
+#define LOG_H
+
+#define DEBUG 0
+#if DEBUG
+#define dbgPrint(...) Serial.print(__VA_ARGS__)
+#define dbgPrintf(...) Serial.printf(__VA_ARGS__)
+#define dbgPrintln(...) Serial.println(__VA_ARGS__)
+#define dbgWrite(...) Serial.write(__VA_ARGS__)
+#else
+#define dbgPrint(...)
+#define dbgPrintf(...)
+#define dbgPrintln(...)
+#define dbgWrite(...)
+#endif
+
+#endif
diff --git a/nrf52/nrf52.ino b/nrf52/nrf52.ino
new file mode 100644
index 0000000..1b4ac3c
--- /dev/null
+++ b/nrf52/nrf52.ino
@@ -0,0 +1,94 @@
+// -*- mode: c++ -*-
+#include "i2c_message.h"
+#include "i2c_ring_buffer.h"
+#include "log.h"
+#include "state_machine.h"
+
+#include <bluefruit.h>
+#include <Wire.h>
+
+BLEDis bledis;
+BLEHidAdafruit blehid;
+
+I2CRingBuffer rb;
+StateMachine fsm(&blehid);
+
+void setup() {
+  pinMode(LED_BUILTIN, OUTPUT);
+  digitalWrite(LED_BUILTIN, HIGH);
+
+  pinMode(PIN_WIRE_SDA, INPUT_PULLUP);
+  pinMode(PIN_WIRE_SCL, INPUT_PULLUP);
+
+  Serial.begin(115200);
+  Serial.println("usb2btle booting.");
+
+  Wire.begin(BTLE_WIREADDR);
+  Wire.onReceive(wireDataReceived);
+
+  Bluefruit.begin();
+  Bluefruit.setTxPower(4);
+  Bluefruit.setName("usb2btle");
+
+  // Configure and Start Device Information Service
+  bledis.setManufacturer("Kublai Khansulting");
+  bledis.setModel("devel-nrf52832-trinketm0");
+  bledis.begin();
+
+  /* Start BLE HID
+   * Note: Apple requires BLE device must have min connection interval >= 20m
+   * ( The smaller the connection interval the faster we could send data).
+   * However for HID and MIDI device, Apple could accept min connection interval
+   * up to 11.25 ms. Therefore BLEHidAdafruit::begin() will try to set the min and max
+   * connection interval to 11.25  ms and 15 ms respectively for best performance.
+   */
+  blehid.begin();
+  blehid.setKeyboardLedCallback(setKeyboardLED);
+
+  startAdv();
+
+  digitalWrite(LED_BUILTIN, LOW);
+}
+
+void startAdv(void)
+{
+  Serial.println("Advertising HID.");
+
+  Bluefruit.Advertising.addFlags(BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE);
+  Bluefruit.Advertising.addTxPower();
+  Bluefruit.Advertising.addAppearance(BLE_APPEARANCE_HID_KEYBOARD);
+  Bluefruit.Advertising.addService(blehid);
+  Bluefruit.Advertising.addName();
+  Bluefruit.Advertising.restartOnDisconnect(true);
+  Bluefruit.Advertising.setInterval(32, 244);
+  Bluefruit.Advertising.setFastTimeout(30);
+  Bluefruit.Advertising.start(0);
+}
+
+void loop() {
+  waitForEvent();
+
+  uint8_t v;
+  while (rb.read(&v)) {
+    dbgPrintf("got byte on rb: %02x\r\n", v);
+    fsm.byteReceived(v);
+  }
+}
+
+void wireDataReceived(int numBytes) {
+  dbgPrintf("wireDataReceived: %u\r\n", numBytes);
+  for (int i = 0; i < numBytes; i++) {
+    rb.write(Wire.read());
+  }
+}
+
+void setKeyboardLED(uint16_t conn_handle, uint8_t led_bitmap) {
+  (void) conn_handle;
+
+  // light up Red Led if any bits is set
+  if (led_bitmap) {
+    ledOn(LED_RED);
+  } else {
+    ledOff(LED_RED);
+  }
+}
diff --git a/nrf52/state_machine.cpp b/nrf52/state_machine.cpp
new file mode 100644
index 0000000..15e38b9
--- /dev/null
+++ b/nrf52/state_machine.cpp
@@ -0,0 +1,79 @@
+#include "state_machine.h"
+
+#include "i2c_message.h"
+#include "log.h"
+
+#include <Arduino.h>
+
+StateMachine::StateMachine(BLEHidAdafruit *blehid): currentState(WAIT_FOR_TYPE), blehid(blehid) {}
+
+void StateMachine::byteReceived(uint8_t inByte) {
+  dbgPrint("inByte=");
+  dbgPrintln(inByte);
+
+  switch (this->currentState) {
+  case WAIT_FOR_TYPE:
+    switch (inByte) {
+    case KBD:
+      digitalWrite(LED_BUILTIN, HIGH);
+      this->msgType = KBD;
+      break;
+
+    case DBG:
+      dbgPrint("T-M0: ");
+      this->msgType = DBG;
+      break;
+
+    default:
+      this->msgType = INVALID;
+      Serial.printf("Invalid message type: %ud.\r\n", inByte);
+    }
+
+    this->currentState = WAIT_FOR_LEN;
+    break;
+
+  case WAIT_FOR_LEN:
+    dbgPrintf("msg len: %u\r\n", inByte);
+    this->msgLen = inByte;
+    this->msgCount = 0;
+
+    if (this->msgLen == 0) {
+      this->currentState = WAIT_FOR_TYPE;
+    } else {
+      this->currentState = WAIT_FOR_DATA;
+    }
+    break;
+
+  case WAIT_FOR_DATA:
+    dbgPrintf("data: %02x\r\n", inByte);
+    switch (this->msgType) {
+    case KBD:
+      this->message[this->msgCount++ % sizeof(this->message)] = inByte;
+      break;
+
+    case DBG:
+      dbgPrint(inByte);
+      break;
+    }
+
+    if (this->msgCount == this->msgLen) {
+      switch (this->msgType) {
+      case KBD:
+        dbgPrintln("sending kbd report");
+        this->blehid->keyboardReport(this->message[0], &this->message[2]);
+        digitalWrite(LED_BUILTIN, LOW);
+        break;
+
+      case DBG:
+        dbgPrintln();
+        break;
+      }
+      this->currentState = WAIT_FOR_TYPE;
+    }
+    break;
+
+  default:
+    Serial.printf("Invalid message state: %ud.\r\n", this->currentState);
+    break;
+  }
+}
diff --git a/nrf52/state_machine.h b/nrf52/state_machine.h
new file mode 100644
index 0000000..d972926
--- /dev/null
+++ b/nrf52/state_machine.h
@@ -0,0 +1,28 @@
+#ifndef STATE_MACHINE_H
+#define STATE_MACHINE_H
+
+#include "i2c_message.h"
+
+#include <bluefruit.h>
+
+#include <stdint.h>
+
+#define MAX_MSG_LEN 32
+
+enum state_t {WAIT_FOR_TYPE, WAIT_FOR_LEN, WAIT_FOR_DATA};
+
+class StateMachine {
+public:
+  StateMachine(BLEHidAdafruit *);
+  void byteReceived(uint8_t);
+
+private:
+  state_t currentState;
+  uint8_t message[MAX_MSG_LEN];
+  uint8_t msgLen, msgCount;
+  i2c_message_t msgType;
+
+  BLEHidAdafruit *blehid;
+};
+
+#endif