Add submission # 6988

#6988

Author: ArduinoBot

registry.txt

@@ -8428,3 +8428,4 @@ https://github.com/RobTillaart/SHT4x.git|Contributed|SHT4x
 https://github.com/dougp2/Multi_Timer_V2.git|Contributed|Multi_Timer_V2
 https://github.com/nonpawite/bcc-esp-dev.git|Contributed|BCC_ESP32S3
 https://github.com/dac1e/RcSwitchTransmitter.git|Contributed|RcSwitchTransmitter
+https://github.com/ennio64/StepperHAL_STM32F4x1-Library.git|Contributed|StepperHAL_STM32F4x1