From 0dbd05505b5f86f8c4e202df3bac394f157532ef Mon Sep 17 00:00:00 2001
From: "Dr.-Ing. Amilcar do Carmo Lucas" <amilcar.lucas@iav.de>
Date: Mon, 8 Mar 2021 19:04:45 +0100
Subject: [PATCH] AP_BLHeli: Remove duplicated code, use existing AP_Math CRC
 function

---
 libraries/AP_BLHeli/AP_BLHeli.cpp | 17 +----------------
 libraries/AP_BLHeli/AP_BLHeli.h   |  1 -
 2 files changed, 1 insertion(+), 17 deletions(-)

diff --git a/libraries/AP_BLHeli/AP_BLHeli.cpp b/libraries/AP_BLHeli/AP_BLHeli.cpp
index 49d9dfa805..02f49baf17 100644
--- a/libraries/AP_BLHeli/AP_BLHeli.cpp
+++ b/libraries/AP_BLHeli/AP_BLHeli.cpp
@@ -1403,21 +1403,6 @@ void AP_BLHeli::init(void)
     }
 }
 
-/*
-  implement the 8 bit CRC used by the BLHeli ESC telemetry protocol
- */
-uint8_t AP_BLHeli::telem_crc8(uint8_t crc, uint8_t crc_seed) const
-{
-    uint8_t crc_u = crc;
-    crc_u ^= crc_seed;
-
-    for (uint8_t i=0; i<8; i++) {
-        crc_u = ( crc_u & 0x80 ) ? 0x7 ^ ( crc_u << 1 ) : ( crc_u << 1 );
-    }
-
-    return crc_u;
-}
-
 /*
   read an ESC telemetry packet
  */
@@ -1432,7 +1417,7 @@ void AP_BLHeli::read_telemetry_packet(void)
     // calculate crc
     uint8_t crc = 0;
     for (uint8_t i=0; i<telem_packet_size-1; i++) {    
-        crc = telem_crc8(buf[i], crc);
+        crc = crc8_dvb(buf[i], crc, 0x07);
     }
 
     if (buf[telem_packet_size-1] != crc) {
diff --git a/libraries/AP_BLHeli/AP_BLHeli.h b/libraries/AP_BLHeli/AP_BLHeli.h
index 536d91f524..d53627fc2f 100644
--- a/libraries/AP_BLHeli/AP_BLHeli.h
+++ b/libraries/AP_BLHeli/AP_BLHeli.h
@@ -285,7 +285,6 @@ private:
     bool BL_VerifyFlash(const uint8_t *buf, uint16_t n);
     void blheli_process_command(void);
     void run_connection_test(uint8_t chan);
-    uint8_t telem_crc8(uint8_t crc, uint8_t crc_seed) const;
     void read_telemetry_packet(void);
     void log_bidir_telemetry(void);