Keyboard: Helix serial.c, split_scom.c bug fix and update (#4191)

* helix/serial.c add support PD1,PD3,PE6 and configuration simplify

* Add comment about ATmega32U4 I2C

* Add compile time check for ATmega32U4 I2C

* change TAB code to 8 SPACE code

* Helix serial.c PORTD,PD0 test. OK

  OK PD0
  -  PD1
  OK PD2
  -  PD3
  -  PE6

* Helix serial.c PORTD,PD1 test. OK

   OK PD0
   OK PD1
   OK PD2
   -  PD3
   -  PE6

* Helix serial.c PORTD,PD3 test. OK

   OK PD0
   OK PD1
   OK PD2
   OK PD3
   -  PE6

* Helix serial.c PORTE,PD6 test. OK

   OK PD0
   OK PD1
   OK PD2
   OK PD3
   OK PE6

* Helix serial.c: PD0,PD1,PD3,PE6 all test end

* Helix serial.c: rename SOFT_SERIAL_PORT to SOFT_SERIAL_PIN

* Helix serial.c add debug code

* Helix serial.c: add transaction ID range check

* Helix serial.c debug code update

* Helix serial.c debug code update

* Helix serial.c: Strict checking of the value of tid.

* adjust the delay of serial.c

* Helix serial.c: remove debug code

* remove EXTRAFLAGS += -DCONSOLE_ENABLE from five_rows/rules.mk

tmk_core/common.mk has
 >ifeq ($(strip $(CONSOLE_ENABLE)), yes)
 >   TMK_COMMON_DEFS += -DCONSOLE_ENABLE

* Fix error handling in split_scomm.c

* add some comment to serial.c

* add some comment about SELECT_SOFT_SERIAL_SPEED

8 files changed, 227 insertions, 135 deletions

diff --git a/keyboards/helix/pico/serial_config.h b/keyboards/helix/pico/serial_config.h
index 82c6e4e83..fc8736d47 100644
--- a/keyboards/helix/pico/serial_config.h
+++ b/keyboards/helix/pico/serial_config.h
@@ -1,16 +1,9 @@
-#ifndef SOFT_SERIAL_CONFIG_H
-#define SOFT_SERIAL_CONFIG_H
+//// #error rev2 serial config
 
+#ifndef SOFT_SERIAL_PIN
 /* Soft Serial defines */
-#define SERIAL_PIN_DDR DDRD
-#define SERIAL_PIN_PORT PORTD
-#define SERIAL_PIN_INPUT PIND
-#define SERIAL_PIN_MASK _BV(PD2)
-#define SERIAL_PIN_INTERRUPT INT2_vect
+#define SOFT_SERIAL_PIN D2
 
 #define SERIAL_SLAVE_BUFFER_LENGTH MATRIX_ROWS/2
 #define SERIAL_MASTER_BUFFER_LENGTH MATRIX_ROWS/2
-
-//// #error rev2 serial config
-
-#endif /* SOFT_SERIAL_CONFIG_H */
+#endif
diff --git a/keyboards/helix/rev1/keymaps/OLED_sample/serial_config.h b/keyboards/helix/rev1/keymaps/OLED_sample/serial_config.h
index b991b874b..f56951e70 100644
--- a/keyboards/helix/rev1/keymaps/OLED_sample/serial_config.h
+++ b/keyboards/helix/rev1/keymaps/OLED_sample/serial_config.h
@@ -1,16 +1,9 @@
-#ifndef SOFT_SERIAL_CONFIG_H
-#define SOFT_SERIAL_CONFIG_H
+//// #error rev1/keymaps/OLED_sample serial config
 
+#ifndef SOFT_SERIAL_PIN
 /* Soft Serial defines */
-#define SERIAL_PIN_DDR DDRD
-#define SERIAL_PIN_PORT PORTD
-#define SERIAL_PIN_INPUT PIND
-#define SERIAL_PIN_MASK _BV(PD2)
-#define SERIAL_PIN_INTERRUPT INT2_vect
+#define SOFT_SERIAL_PIN D2
 
 #define SERIAL_SLAVE_BUFFER_LENGTH MATRIX_ROWS/2
 #define SERIAL_MASTER_BUFFER_LENGTH 0
-
-//// #error rev1/keymaps/OLED_sample serial config
-
-#endif /* SOFT_SERIAL_CONFIG_H */
+#endif
diff --git a/keyboards/helix/rev1/serial_config.h b/keyboards/helix/rev1/serial_config.h
index 51c6aa375..32218f9bb 100644
--- a/keyboards/helix/rev1/serial_config.h
+++ b/keyboards/helix/rev1/serial_config.h
@@ -1,16 +1,9 @@
-#ifndef SOFT_SERIAL_CONFIG_H
-#define SOFT_SERIAL_CONFIG_H
+/// #error rev1 serial config
 
+#ifndef SOFT_SERIAL_PIN
 /* Soft Serial defines */
-#define SERIAL_PIN_DDR DDRD
-#define SERIAL_PIN_PORT PORTD
-#define SERIAL_PIN_INPUT PIND
-#define SERIAL_PIN_MASK _BV(PD0)
-#define SERIAL_PIN_INTERRUPT INT0_vect
+#define SOFT_SERIAL_PIN D0
 
 #define SERIAL_SLAVE_BUFFER_LENGTH MATRIX_ROWS/2
 #define SERIAL_MASTER_BUFFER_LENGTH 0
-
-/// #error rev1 serial config
-
-#endif /* SOFT_SERIAL_CONFIG_H */
+#endif
diff --git a/keyboards/helix/rev2/keymaps/five_rows/rules.mk b/keyboards/helix/rev2/keymaps/five_rows/rules.mk
index 63106df76..f771c94c9 100644
--- a/keyboards/helix/rev2/keymaps/five_rows/rules.mk
+++ b/keyboards/helix/rev2/keymaps/five_rows/rules.mk
@@ -122,10 +122,6 @@ ifeq ($(strip $(Link_Time_Optimization)),yes)
     EXTRAFLAGS += -flto -DUSE_Link_Time_Optimization
 endif
 
-ifeq ($(strip $(CONSOLE_ENABLE)),yes)
-    EXTRAFLAGS += -DCONSOLE_ENABLE
-endif
-
 # Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
 SLEEP_LED_ENABLE = no    # Breathing sleep LED during USB suspend
 
diff --git a/keyboards/helix/rev2/serial_config.h b/keyboards/helix/rev2/serial_config.h
index 8d7e62837..37135213d 100644
--- a/keyboards/helix/rev2/serial_config.h
+++ b/keyboards/helix/rev2/serial_config.h
@@ -1,15 +1,8 @@
-#ifndef SOFT_SERIAL_CONFIG_H
-#define SOFT_SERIAL_CONFIG_H
+//// #error rev2 serial config
 
+#ifndef SOFT_SERIAL_PIN
 /* Soft Serial defines */
-#define SERIAL_PIN_DDR DDRD
-#define SERIAL_PIN_PORT PORTD
-#define SERIAL_PIN_INPUT PIND
-#define SERIAL_PIN_MASK _BV(PD2)
-#define SERIAL_PIN_INTERRUPT INT2_vect
+#define SOFT_SERIAL_PIN D2
 
 #define SERIAL_USE_MULTI_TRANSACTION
-
-//// #error rev2 serial config
-
-#endif /* SOFT_SERIAL_CONFIG_H */
+#endif
diff --git a/keyboards/helix/rev2/split_scomm.c b/keyboards/helix/rev2/split_scomm.c
index 9719eb22e..50d233ce9 100644
--- a/keyboards/helix/rev2/split_scomm.c
+++ b/keyboards/helix/rev2/split_scomm.c
@@ -10,6 +10,9 @@
 #ifdef SERIAL_DEBUG_MODE
 #include <avr/io.h>
 #endif
+#ifdef CONSOLE_ENABLE
+  #include <print.h>
+#endif
 
 uint8_t volatile serial_slave_buffer[SERIAL_SLAVE_BUFFER_LENGTH] = {0};
 uint8_t volatile serial_master_buffer[SERIAL_MASTER_BUFFER_LENGTH] = {0};
@@ -17,6 +20,7 @@ uint8_t volatile status_com = 0;
 uint8_t volatile status1 = 0;
 uint8_t slave_buffer_change_count = 0;
 uint8_t s_change_old = 0xff;
+uint8_t s_change_new = 0xff;
 
 SSTD_t transactions[] = {
 #define GET_SLAVE_STATUS 0
@@ -41,12 +45,12 @@ SSTD_t transactions[] = {
 
 void serial_master_init(void)
 {
-    soft_serial_initiator_init(transactions);
+    soft_serial_initiator_init(transactions, TID_LIMIT(transactions));
 }
 
 void serial_slave_init(void)
 {
-    soft_serial_target_init(transactions);
+    soft_serial_target_init(transactions, TID_LIMIT(transactions));
 }
 
 // 0 => no error
@@ -54,19 +58,37 @@ void serial_slave_init(void)
 // 2 => checksum error
 int serial_update_buffers(int master_update)
 {
-    int status;
+    int status, smatstatus;
     static int need_retry = 0;
-    if( s_change_old != slave_buffer_change_count ) {
-        status = soft_serial_transaction(GET_SLAVE_BUFFER);
-        if( status == TRANSACTION_END )
-            s_change_old = slave_buffer_change_count;
+
+    if( s_change_old != s_change_new ) {
+        smatstatus = soft_serial_transaction(GET_SLAVE_BUFFER);
+        if( smatstatus == TRANSACTION_END ) {
+            s_change_old = s_change_new;
+#ifdef CONSOLE_ENABLE
+            uprintf("slave matrix = %b %b %b %b %b\n",
+                    serial_slave_buffer[0], serial_slave_buffer[1],
+                    serial_slave_buffer[2], serial_slave_buffer[3],
+                    serial_slave_buffer[4] );
+#endif
+        }
+    } else {
+        // serial_slave_buffer dosen't change
+        smatstatus = TRANSACTION_END; // dummy status
+    }
+
+    if( !master_update && !need_retry) {
+        status = soft_serial_transaction(GET_SLAVE_STATUS);
+    } else {
+        status = soft_serial_transaction(PUT_MASTER_GET_SLAVE_STATUS);
+    }
+    if( status == TRANSACTION_END ) {
+        s_change_new = slave_buffer_change_count;
+        need_retry = 0;
+    } else {
+        need_retry = 1;
     }
-    if( !master_update && !need_retry)
-        status = soft_serial_transaction(GET_SLAVE_STATUS);
-    else
-        status = soft_serial_transaction(PUT_MASTER_GET_SLAVE_STATUS);
-    need_retry = ( status == TRANSACTION_END ) ? 0 : 1;
-    return status;
+    return smatstatus;
 }
 
 #endif // SERIAL_USE_MULTI_TRANSACTION
diff --git a/keyboards/helix/serial.c b/keyboards/helix/serial.c
index 11ceff0b3..830f86b55 100644
--- a/keyboards/helix/serial.c
+++ b/keyboards/helix/serial.c
@@ -14,7 +14,56 @@
 #include "serial.h"
 //#include <pro_micro.h>
 
-#ifdef USE_SERIAL
+#ifdef SOFT_SERIAL_PIN
+
+#ifdef __AVR_ATmega32U4__
+  // if using ATmega32U4 I2C, can not use PD0 and PD1 in soft serial.
+  #ifdef USE_I2C
+    #if SOFT_SERIAL_PIN == D0 || SOFT_SERIAL_PIN == D1
+      #error Using ATmega32U4 I2C, so can not use PD0, PD1
+    #endif
+  #endif
+
+  #if SOFT_SERIAL_PIN >= D0 && SOFT_SERIAL_PIN <= D3
+    #define SERIAL_PIN_DDR   DDRD
+    #define SERIAL_PIN_PORT  PORTD
+    #define SERIAL_PIN_INPUT PIND
+    #if SOFT_SERIAL_PIN == D0
+      #define SERIAL_PIN_MASK _BV(PD0)
+      #define EIMSK_BIT       _BV(INT0)
+      #define EICRx_BIT       (~(_BV(ISC00) | _BV(ISC01)))
+      #define SERIAL_PIN_INTERRUPT INT0_vect
+    #elif  SOFT_SERIAL_PIN == D1
+      #define SERIAL_PIN_MASK _BV(PD1)
+      #define EIMSK_BIT       _BV(INT1)
+      #define EICRx_BIT       (~(_BV(ISC10) | _BV(ISC11)))
+      #define SERIAL_PIN_INTERRUPT INT1_vect
+    #elif  SOFT_SERIAL_PIN == D2
+      #define SERIAL_PIN_MASK _BV(PD2)
+      #define EIMSK_BIT       _BV(INT2)
+      #define EICRx_BIT       (~(_BV(ISC20) | _BV(ISC21)))
+      #define SERIAL_PIN_INTERRUPT INT2_vect
+    #elif  SOFT_SERIAL_PIN == D3
+      #define SERIAL_PIN_MASK _BV(PD3)
+      #define EIMSK_BIT       _BV(INT3)
+      #define EICRx_BIT       (~(_BV(ISC30) | _BV(ISC31)))
+      #define SERIAL_PIN_INTERRUPT INT3_vect
+    #endif
+  #elif  SOFT_SERIAL_PIN == E6
+    #define SERIAL_PIN_DDR   DDRE
+    #define SERIAL_PIN_PORT  PORTE
+    #define SERIAL_PIN_INPUT PINE
+    #define SERIAL_PIN_MASK  _BV(PE6)
+    #define EIMSK_BIT        _BV(INT6)
+    #define EICRx_BIT        (~(_BV(ISC60) | _BV(ISC61)))
+    #define SERIAL_PIN_INTERRUPT INT6_vect
+  #else
+  #error invalid SOFT_SERIAL_PIN value
+  #endif
+
+#else
+ #error serial.c now support ATmega32U4 only
+#endif
 
 #ifndef SERIAL_USE_MULTI_TRANSACTION
 /* --- USE Simple API (OLD API, compatible with let's split serial.c) */
@@ -42,16 +91,20 @@ SSTD_t transactions[] = {
 };
 
 void serial_master_init(void)
-{ soft_serial_initiator_init(transactions); }
+{ soft_serial_initiator_init(transactions, TID_LIMIT(transactions)); }
 
 void serial_slave_init(void)
-{ soft_serial_target_init(transactions); }
+{ soft_serial_target_init(transactions, TID_LIMIT(transactions)); }
 
 // 0 => no error
 // 1 => slave did not respond
 // 2 => checksum error
 int serial_update_buffers()
-{ return soft_serial_transaction(); }
+{
+    int result;
+    result = soft_serial_transaction();
+    return result;
+}
 
 #endif // Simple API (OLD API, compatible with let's split serial.c)
 
@@ -59,39 +112,66 @@ int serial_update_buffers()
 #define NO_INLINE __attribute__((noinline))
 #define _delay_sub_us(x)    __builtin_avr_delay_cycles(x)
 
-// Serial pulse period in microseconds.
-#define TID_SEND_ADJUST 14
+// parity check
+#define ODD_PARITY 1
+#define EVEN_PARITY 0
+#define PARITY EVEN_PARITY
+
+#ifdef SERIAL_DELAY
+  // custom setup in config.h
+  // #define TID_SEND_ADJUST 2
+  // #define SERIAL_DELAY 6             // micro sec
+  // #define READ_WRITE_START_ADJUST 30 // cycles
+  // #define READ_WRITE_WIDTH_ADJUST 8 // cycles
+#else
+// ============ Standard setups ============
+
+#ifndef SELECT_SOFT_SERIAL_SPEED
+#define SELECT_SOFT_SERIAL_SPEED 1
+//  0: about 189kbps
+//  1: about 137kbps (default)
+//  2: about 75kbps
+//  3: about 39kbps
+//  4: about 26kbps
+//  5: about 20kbps
+#endif
+
+#define TID_SEND_ADJUST 2
 
-#define SELECT_SERIAL_SPEED 1
-#if SELECT_SERIAL_SPEED == 0
+#if SELECT_SOFT_SERIAL_SPEED == 0
   // Very High speed
   #define SERIAL_DELAY 4             // micro sec
   #define READ_WRITE_START_ADJUST 33 // cycles
-  #define READ_WRITE_WIDTH_ADJUST 3 // cycles
-#elif SELECT_SERIAL_SPEED == 1
+  #define READ_WRITE_WIDTH_ADJUST 6 // cycles
+#elif SELECT_SOFT_SERIAL_SPEED == 1
   // High speed
   #define SERIAL_DELAY 6             // micro sec
   #define READ_WRITE_START_ADJUST 30 // cycles
-  #define READ_WRITE_WIDTH_ADJUST 3 // cycles
-#elif SELECT_SERIAL_SPEED == 2
+  #define READ_WRITE_WIDTH_ADJUST 7 // cycles
+#elif SELECT_SOFT_SERIAL_SPEED == 2
   // Middle speed
   #define SERIAL_DELAY 12            // micro sec
   #define READ_WRITE_START_ADJUST 30 // cycles
-  #define READ_WRITE_WIDTH_ADJUST 3 // cycles
-#elif SELECT_SERIAL_SPEED == 3
+  #define READ_WRITE_WIDTH_ADJUST 7 // cycles
+#elif SELECT_SOFT_SERIAL_SPEED == 3
   // Low speed
   #define SERIAL_DELAY 24            // micro sec
   #define READ_WRITE_START_ADJUST 30 // cycles
-  #define READ_WRITE_WIDTH_ADJUST 3 // cycles
-#elif SELECT_SERIAL_SPEED == 4
+  #define READ_WRITE_WIDTH_ADJUST 7 // cycles
+#elif SELECT_SOFT_SERIAL_SPEED == 4
   // Very Low speed
-  #define SERIAL_DELAY 50            // micro sec
+  #define SERIAL_DELAY 36            // micro sec
+  #define READ_WRITE_START_ADJUST 30 // cycles
+  #define READ_WRITE_WIDTH_ADJUST 7 // cycles
+#elif SELECT_SOFT_SERIAL_SPEED == 5
+  // Ultra Low speed
+  #define SERIAL_DELAY 48            // micro sec
   #define READ_WRITE_START_ADJUST 30 // cycles
-  #define READ_WRITE_WIDTH_ADJUST 3 // cycles
+  #define READ_WRITE_WIDTH_ADJUST 7 // cycles
 #else
-#error Illegal Serial Speed
-#endif
-
+#error invalid SELECT_SOFT_SERIAL_SPEED value
+#endif /* SELECT_SOFT_SERIAL_SPEED */
+#endif /* SERIAL_DELAY */
 
 #define SERIAL_DELAY_HALF1 (SERIAL_DELAY/2)
 #define SERIAL_DELAY_HALF2 (SERIAL_DELAY - SERIAL_DELAY/2)
@@ -105,6 +185,7 @@ int serial_update_buffers()
 #endif
 
 static SSTD_t *Transaction_table = NULL;
+static uint8_t Transaction_table_size = 0;
 
 inline static
 void serial_delay(void) {
@@ -152,30 +233,28 @@ void serial_high(void) {
   SERIAL_PIN_PORT |= SERIAL_PIN_MASK;
 }
 
-void soft_serial_initiator_init(SSTD_t *sstd_table)
+void soft_serial_initiator_init(SSTD_t *sstd_table, int sstd_table_size)
 {
     Transaction_table = sstd_table;
+    Transaction_table_size = (uint8_t)sstd_table_size;
     serial_output();
     serial_high();
 }
 
-void soft_serial_target_init(SSTD_t *sstd_table)
+void soft_serial_target_init(SSTD_t *sstd_table, int sstd_table_size)
 {
     Transaction_table = sstd_table;
+    Transaction_table_size = (uint8_t)sstd_table_size;
     serial_input_with_pullup();
 
-#if SERIAL_PIN_MASK == _BV(PD0)
-    // Enable INT0
-    EIMSK |= _BV(INT0);
-    // Trigger on falling edge of INT0
-    EICRA &= ~(_BV(ISC00) | _BV(ISC01));
-#elif SERIAL_PIN_MASK == _BV(PD2)
-    // Enable INT2
-    EIMSK |= _BV(INT2);
-    // Trigger on falling edge of INT2
-    EICRA &= ~(_BV(ISC20) | _BV(ISC21));
+    // Enable INT0-INT3,INT6
+    EIMSK |= EIMSK_BIT;
+#if SERIAL_PIN_MASK == _BV(PE6)
+    // Trigger on falling edge of INT6
+    EICRB &= EICRx_BIT;
 #else
- #error unknown SERIAL_PIN_MASK value
+    // Trigger on falling edge of INT0-INT3
+    EICRA &= EICRx_BIT;
 #endif
 }
 
@@ -205,12 +284,12 @@ static uint8_t serial_read_chunk(uint8_t *pterrcount, uint8_t bit) {
     uint8_t byte, i, p, pb;
 
   _delay_sub_us(READ_WRITE_START_ADJUST);
-  for( i = 0, byte = 0, p = 0; i < bit; i++ ) {
+  for( i = 0, byte = 0, p = PARITY; i < bit; i++ ) {
       serial_delay_half1();   // read the middle of pulses
       if( serial_read_pin() ) {
-          byte = (byte << 1) | 1; p ^= 1;
+          byte = (byte << 1) | 1; p ^= 1;
       } else {
-          byte = (byte << 1) | 0; p ^= 0;
+          byte = (byte << 1) | 0; p ^= 0;
       }
       _delay_sub_us(READ_WRITE_WIDTH_ADJUST);
       serial_delay_half2();
@@ -230,13 +309,13 @@ static uint8_t serial_read_chunk(uint8_t *pterrcount, uint8_t bit) {
 void serial_write_chunk(uint8_t data, uint8_t bit) NO_INLINE;
 void serial_write_chunk(uint8_t data, uint8_t bit) {
     uint8_t b, p;
-    for( p = 0, b = 1<<(bit-1); b ; b >>= 1) {
-        if(data & b) {
-            serial_high(); p ^= 1;
-        } else {
-            serial_low();  p ^= 0;
-        }
-        serial_delay();
+    for( p = PARITY, b = 1<<(bit-1); b ; b >>= 1) {
+        if(data & b) {
+            serial_high(); p ^= 1;
+        } else {
+            serial_low();  p ^= 0;
+        }
+        serial_delay();
     }
     /* send parity bit */
     if(p & 1) { serial_high(); }
@@ -288,6 +367,13 @@ void change_reciver2sender(void) {
     serial_delay_half1(); //4
 }
 
+static inline uint8_t nibble_bits_count(uint8_t bits)
+{
+    bits = (bits & 0x5) + (bits >> 1 & 0x5);
+    bits = (bits & 0x3) + (bits >> 2 & 0x3);
+    return bits;
+}
+
 // interrupt handle to be used by the target device
 ISR(SERIAL_PIN_INTERRUPT) {
 
@@ -297,12 +383,15 @@ ISR(SERIAL_PIN_INTERRUPT) {
   SSTD_t *trans = Transaction_table;
 #else
   // recive transaction table index
-  uint8_t tid;
+  uint8_t tid, bits;
   uint8_t pecount = 0;
   sync_recv();
-  tid = serial_read_chunk(&pecount,4);
-  if(pecount> 0)
+  bits = serial_read_chunk(&pecount,7);
+  tid = bits>>3;
+  bits = (bits&7) != nibble_bits_count(tid);
+  if( bits || pecount> 0 || tid > Transaction_table_size ) {
       return;
+  }
   serial_delay_half1();
 
   serial_high(); // response step1 low->high
@@ -315,17 +404,17 @@ ISR(SERIAL_PIN_INTERRUPT) {
   // target send phase
   if( trans->target2initiator_buffer_size > 0 )
       serial_send_packet((uint8_t *)trans->target2initiator_buffer,
-                         trans->target2initiator_buffer_size);
+                         trans->target2initiator_buffer_size);
   // target switch to input
   change_sender2reciver();
 
   // target recive phase
   if( trans->initiator2target_buffer_size > 0 ) {
       if (serial_recive_packet((uint8_t *)trans->initiator2target_buffer,
-                               trans->initiator2target_buffer_size) ) {
-          *trans->status = TRANSACTION_ACCEPTED;
+                               trans->initiator2target_buffer_size) ) {
+          *trans->status = TRANSACTION_ACCEPTED;
       } else {
-          *trans->status = TRANSACTION_DATA_ERROR;
+          *trans->status = TRANSACTION_DATA_ERROR;
       }
   } else {
       *trans->status = TRANSACTION_ACCEPTED;
@@ -349,6 +438,8 @@ int  soft_serial_transaction(void) {
   SSTD_t *trans = Transaction_table;
 #else
 int  soft_serial_transaction(int sstd_index) {
+  if( sstd_index > Transaction_table_size )
+      return TRANSACTION_TYPE_ERROR;
   SSTD_t *trans = &Transaction_table[sstd_index];
 #endif
   cli();
@@ -375,9 +466,10 @@ int  soft_serial_transaction(int sstd_index) {
 
 #else
   // send transaction table index
+  int tid = (sstd_index<<3) | (7 & nibble_bits_count(sstd_index));
   sync_send();
   _delay_sub_us(TID_SEND_ADJUST);
-  serial_write_chunk(sstd_index, 4);
+  serial_write_chunk(tid, 7);
   serial_delay_half1();
 
   // wait for the target response (step1 low->high)
@@ -389,12 +481,12 @@ int  soft_serial_transaction(int sstd_index) {
   // check if the target is present (step2 high->low)
   for( int i = 0; serial_read_pin(); i++ ) {
       if (i > SLAVE_INT_ACK_WIDTH + 1) {
-          // slave failed to pull the line low, assume not present
-          serial_output();
-          serial_high();
-          *trans->status = TRANSACTION_NO_RESPONSE;
-          sei();
-          return TRANSACTION_NO_RESPONSE;
+          // slave failed to pull the line low, assume not present
+          serial_output();
+          serial_high();
+          *trans->status = TRANSACTION_NO_RESPONSE;
+          sei();
+          return TRANSACTION_NO_RESPONSE;
       }
       _delay_sub_us(SLAVE_INT_ACK_WIDTH_UNIT);
   }
@@ -404,12 +496,12 @@ int  soft_serial_transaction(int sstd_index) {
   // if the target is present syncronize with it
   if( trans->target2initiator_buffer_size > 0 ) {
       if (!serial_recive_packet((uint8_t *)trans->target2initiator_buffer,
-                                trans->target2initiator_buffer_size) ) {
-          serial_output();
-          serial_high();
-          *trans->status = TRANSACTION_DATA_ERROR;
-          sei();
-          return TRANSACTION_DATA_ERROR;
+                                trans->target2initiator_buffer_size) ) {
+          serial_output();
+          serial_high();
+          *trans->status = TRANSACTION_DATA_ERROR;
+          sei();
+          return TRANSACTION_DATA_ERROR;
       }
    }
 
@@ -419,7 +511,7 @@ int  soft_serial_transaction(int sstd_index) {
   // initiator send phase
   if( trans->initiator2target_buffer_size > 0 ) {
       serial_send_packet((uint8_t *)trans->initiator2target_buffer,
-                         trans->initiator2target_buffer_size);
+                         trans->initiator2target_buffer_size);
   }
 
   // always, release the line when not in use
@@ -442,3 +534,9 @@ int soft_serial_get_and_clean_status(int sstd_index) {
 #endif
 
 #endif
+
+// Helix serial.c history
+//   2018-1-29 fork from let's split (#2308)
+//   2018-6-28 bug fix master to slave comm (#3255)
+//   2018-8-11 improvements (#3608)
+//   2018-10-21 fix serial and RGB animation conflict (#4191)
diff --git a/keyboards/helix/serial.h b/keyboards/helix/serial.h
index d2b7fd8e6..7e0c0847a 100644
--- a/keyboards/helix/serial.h
+++ b/keyboards/helix/serial.h
@@ -4,14 +4,16 @@
 #include <stdbool.h>
 
 // /////////////////////////////////////////////////////////////////
-// Need Soft Serial defines in serial_config.h
+// Need Soft Serial defines in config.h
 // /////////////////////////////////////////////////////////////////
 // ex.
-//  #define SERIAL_PIN_DDR DDRD
-//  #define SERIAL_PIN_PORT PORTD
-//  #define SERIAL_PIN_INPUT PIND
-//  #define SERIAL_PIN_MASK _BV(PD?)   ?=0,2
-//  #define SERIAL_PIN_INTERRUPT INT?_vect  ?=0,2
+//  #define SOFT_SERIAL_PIN ??   // ?? = D0,D1,D2,D3,E6
+//  OPTIONAL: #define SELECT_SOFT_SERIAL_SPEED ? // ? = 1,2,3,4,5
+//                                               //  1: about 137kbps (default)
+//                                               //  2: about 75kbps
+//                                               //  3: about 39kbps
+//                                               //  4: about 26kbps
+//                                               //  5: about 20kbps
 //
 // //// USE Simple API (OLD API, compatible with let's split serial.c)
 // ex.
@@ -47,16 +49,18 @@ typedef struct _SSTD_t  {
     uint8_t target2initiator_buffer_size;
     uint8_t *target2initiator_buffer;
 } SSTD_t;
+#define TID_LIMIT( table ) (sizeof(table) / sizeof(SSTD_t))
 
 // initiator is transaction start side
-void soft_serial_initiator_init(SSTD_t *sstd_table);
+void soft_serial_initiator_init(SSTD_t *sstd_table, int sstd_table_size);
 // target is interrupt accept side
-void soft_serial_target_init(SSTD_t *sstd_table);
+void soft_serial_target_init(SSTD_t *sstd_table, int sstd_table_size);
 
 // initiator resullt
 #define TRANSACTION_END 0
 #define TRANSACTION_NO_RESPONSE 0x1
 #define TRANSACTION_DATA_ERROR  0x2
+#define TRANSACTION_TYPE_ERROR  0x4
 #ifndef SERIAL_USE_MULTI_TRANSACTION
 int  soft_serial_transaction(void);
 #else
@@ -72,7 +76,7 @@ int  soft_serial_transaction(int sstd_index);
 //   target:
 //       TRANSACTION_DATA_ERROR
 //    or TRANSACTION_ACCEPTED
-#define TRANSACTION_ACCEPTED 0x4
+#define TRANSACTION_ACCEPTED 0x8
 #ifdef SERIAL_USE_MULTI_TRANSACTION
 int  soft_serial_get_and_clean_status(int sstd_index);
 #endif