# Retrofit

* A sewing machine only turns one way, turn wheel toward operator / anti-clock
  Forward/Backward sewing is done mechanically (hook movement reversed)

## Add a rotary position sensor on the wheel

* To detect needle position : up, down
  can be two cams with a slotted optical sensor
* To get a tachometer signal for speed control
  can be a holed wheel with a slotted optical sensor

* AMS AS5132 Rotary Sensor
  8.5-bit rotary position sensor with digital angle (interface), ABI, UVW (up to 6 pole pairs) and PWM output
  https://ams.com/as5132

  360 positions per revolution
  Serial interface
  PWM output
  Incremental output with adjustable number of pulses
  Max RPM 72_900

* AMS AS5134
  https://ams.com/as5134
  https://ams.com/as5134#tab/shop-now
  https://www.mouser.fr/Search/Refine?Keyword=ams+AS5134
  ZSST / ZSSM ??? tape/reel ???
  8$/unit

## Motor Driver
