Adds helper functions to generate different DCC packet types:

src/dcc/Packet.cxx

@@ -69,6 +69,10 @@ enum
     DCC_FUNCTION2_F9 = 0b10100000,
     DCC_FEATURE_EXP_F13 = 0b11011110,
     DCC_FEATURE_EXP_F21 = 0b11011111,
+    DCC_FEATURE_EXP_FNHI = 0b11011000,
+    DCC_BINARY_SHORT = 0b11011101,
+    DCC_BINARY_LONG = 0b11000000,
+    DCC_ANALOG_FN = 0b00111101,
 
     DCC_PROG_READ1 = 0b11100100,
     DCC_PROG_WRITE1 = 0b11101100,
@@ -234,17 +238,39 @@ void Packet::add_dcc_function9_12(unsigned values)
     add_dcc_checksum();
 }
 
-void Packet::add_dcc_function13_20(unsigned values)
+void Packet::add_dcc_function_hi(uint8_t base, uint8_t values)
 {
-    payload[dlc++] = DCC_FEATURE_EXP_F13;
-    payload[dlc++] = values & 0xff;
+    base -= 13;
+    HASSERT((base & 0b111) == 0);
+    HASSERT(base <= (61 - 13));
+    base >>= 3;
+    base -= 2;
+    payload[dlc++] = DCC_FEATURE_EXP_FNHI | (base & 0b111);
+    payload[dlc++] = values;
     add_dcc_checksum();
 }
 
-void Packet::add_dcc_function21_28(unsigned values)
+void Packet::add_dcc_binary_state(uint16_t fn, bool value)
 {
-    payload[dlc++] = DCC_FEATURE_EXP_F21;
-    payload[dlc++] = values & 0xff;
+    if (fn <= 127)
+    {
+        payload[dlc++] = DCC_BINARY_SHORT;
+        payload[dlc++] = fn | (value ? 0x80 : 0);
+    }
+    else
+    {
+        payload[dlc++] = DCC_BINARY_LONG;
+        payload[dlc++] = (fn & 0x7F) | (value ? 0x80 : 0);
+        payload[dlc++] = (fn >> 8) & 0xFF;
+    }
+    add_dcc_checksum();
+}
+
+void Packet::add_dcc_analog_function(uint8_t fn, uint8_t value)
+{
+    payload[dlc++] = DCC_ANALOG_FN;
+    payload[dlc++] = fn;
+    payload[dlc++] = value;
     add_dcc_checksum();
 }
 

src/dcc/Packet.cxxtest

@@ -172,6 +172,75 @@ TEST_F(PacketTest, Fn20)
     EXPECT_THAT(get_packet(), ElementsAre(55, 0b11011111, 0xAA, _));
 }
 
+TEST_F(PacketTest, Fn29)
+{
+    pkt_.add_dcc_address(DccShortAddress(55));
+    pkt_.add_dcc_function_hi(29, 0x5A);
+    EXPECT_THAT(get_packet(), ElementsAre(55, 0b11011000, 0x5A, _));
+}
+
+TEST_F(PacketTest, Fn37)
+{
+    pkt_.add_dcc_address(DccShortAddress(55));
+    pkt_.add_dcc_function_hi(37, 0x11);
+    EXPECT_THAT(get_packet(), ElementsAre(55, 0b11011001, 0x11, _));
+}
+
+TEST_F(PacketTest, Fn45)
+{
+    pkt_.add_dcc_address(DccShortAddress(55));
+    pkt_.add_dcc_function_hi(45, 0x11);
+    EXPECT_THAT(get_packet(), ElementsAre(55, 0b11011010, 0x11, _));
+}
+
+TEST_F(PacketTest, Fn53)
+{
+    pkt_.add_dcc_address(DccShortAddress(55));
+    pkt_.add_dcc_function_hi(53, 0x11);
+    EXPECT_THAT(get_packet(), ElementsAre(55, 0b11011011, 0x11, _));
+}
+
+TEST_F(PacketTest, Fn61)
+{
+    pkt_.add_dcc_address(DccShortAddress(55));
+    pkt_.add_dcc_function_hi(61, 0x11);
+    EXPECT_THAT(get_packet(), ElementsAre(55, 0b11011100, 0x11, _));
+}
+
+TEST_F(PacketTest, BinaryStateShort)
+{
+    pkt_.add_dcc_address(DccShortAddress(55));
+    pkt_.add_dcc_binary_state(61, true);
+    EXPECT_THAT(get_packet(), ElementsAre(55, 0b11011101, 61 | 0x80, _));
+}
+
+TEST_F(PacketTest, BinaryStateShortOff)
+{
+    pkt_.add_dcc_address(DccShortAddress(55));
+    pkt_.add_dcc_binary_state(127, false);
+    EXPECT_THAT(get_packet(), ElementsAre(55, 0b11011101, 127, _));
+}
+
+TEST_F(PacketTest, BinaryStateLongOn)
+{
+    pkt_.add_dcc_address(DccShortAddress(55));
+    pkt_.add_dcc_binary_state(16 * 256 + 61, true);
+    EXPECT_THAT(get_packet(), ElementsAre(55, 0b11000000, 61 + 0x80, 16, _));
+}
+
+TEST_F(PacketTest, BinaryStateLongOff)
+{
+    pkt_.add_dcc_address(DccShortAddress(55));
+    pkt_.add_dcc_binary_state(16 * 256 + 61, false);
+    EXPECT_THAT(get_packet(), ElementsAre(55, 0b11000000, 61, 16, _));
+}
+
+TEST_F(PacketTest, AnalogFunction)
+{
+    pkt_.add_dcc_address(DccShortAddress(55));
+    pkt_.add_dcc_analog_function(17, 99);
+    EXPECT_THAT(get_packet(), ElementsAre(55, 0b00111101, 17, 99, _));
+}
 
 TEST_F(PacketTest, DccBasicAccyOn)
 {

src/dcc/Packet.hxx

@@ -182,11 +182,34 @@ struct Packet : public DCCPacket
     /** Adds a DCC function group command to the packet. The lowest numbered
      * function is always at bit zero. @param values are bitmask of functions
      * to send to the loco. */
-    void add_dcc_function13_20(unsigned values);
+    void add_dcc_function13_20(unsigned values)
+    {
+        add_dcc_function_hi(13, values);
+    }
     /** Adds a DCC function group command to the packet. The lowest numbered
      * function is always at bit zero. @param values are bitmask of functions
      * to send to the loco. */
-    void add_dcc_function21_28(unsigned values);
+    void add_dcc_function21_28(unsigned values)
+    {
+        add_dcc_function_hi(21, values);
+    }
+    /** Adds a DCC function group command to the packet. The lowest numbered
+     * function is always at bit zero.
+     * @param base is a valid function number base, 13, 21, 29, 37, 45, 53
+     * or 61.
+     * @param values are bitmask of functions to send to the loco. */
+    void add_dcc_function_hi(uint8_t base, uint8_t values);
+
+    /** Adds a DCC binary state control command to the packet. Automatically
+     * picks the short or long form, depending on the range of the argument.
+     * @param fn is a binary function variable, 0 to 32767.
+     * @param value true/false, what to set to. */
+    void add_dcc_binary_state(uint16_t fn, bool value);
+
+    /** Adds a DCC analog function control command to the packet.
+     * @param fn is an analog function variable, 0 to 255.
+     * @param value to set it to, 0 to 255. */
+    void add_dcc_analog_function(uint8_t fn, uint8_t value);
 
     /** Helper function for adding programming mode packets. */
     void add_dcc_prog_command(