Make a electrical ruler

I make a electrical ruler.

Feature:

  • Use 32bit microcontroller STM32C8T6.
  • Use 512 line encoder .
  • Precision 0.1mm.
  • unit :mm,cm,meter and km.

    Material:

    STM32C8T6

    512 line encoder

    OLED display

    etc.

    Step 1: Design a STM32 board

    Make a electrical ruler

    Sorry for my bad english!

    I am 24 years old engineering student from Guangxi in China. It's my frist post arcitle.I want to make some friends to help me learn english.:)

    Frist,I design a stm32 PCB board,it include some buttons,crystal,and usb to usart IC CP2102,5V to 3V regulator.

    And then,I spent 30RMB (about $6) to make PCB board.Make a PCB board is cheap and easy in China,10cm*10cm,10PCS PCB just olny 50RMB (about $8).

    Step 2: Solder your STM32 board

    Make a electrical ruler

    About a week,PCB factory will send PCB boards to you by experess,so,you can solder your PCB board now.

    Step 3: Make a wheel by CNC

    Make a electrical ruler

    My friends has a CNC machine,so,I use the CNC machine to cut the acrylic board,and make a wheel and some structures.

    Step 4: Install wheel to encoder

    Make a electrical ruler
    Make a electrical ruler
    Make a electrical ruler
    Make a electrical ruler

    I buy a 512 line incremental encoder from www.taobao.com,taobao.com just like ebay in China.

    This mini incremental encoder about $40,and 512 line meaning every one revolution the encoder will output 512 pulses.

    The wheel diameter is 16.3mm,so the wheel perimeter is 16.3mm*3.1415926≈51.2

    mm,and every one revolution the encoder will output 512 pulses,so,every pulse correspond 51.2 mm/512 pulse=0.1mm length.

    Step 5: Add OLED display and Li-ion battery

    Make a electrical ruler
    Make a electrical ruler

    OLED display cost $1.5 in China,3.3V power supply ,SPI interface and 128*64 pix.

    Step 6: Program and testing

    Make a electrical ruler
    Make a electrical ruler
    Make a electrical ruler

    I use the saleae logic to show the encoder pulse wave,and I use Keil MDK to program STM32.

    This encoder has 4 pins,VCC,PULSE,DIRECTION,and GROUND.if you turn the encoder ,encoder will output some pulses,if DIRECTION pin is High ,meaning direction is foreward,else if DIRECTION pin is Low,meaning direction is backward.

    the STM32F103C8T6 has a encoder interface in GPIOA 12,so I connect PULSE to STM32 GPIOA 12,and DIRECTION connect to GPIOA 11.

    OLED showing my school name ,project name and software version .Do you know Chinese ? :)

    Step 7: Show time!

    Make a electrical ruler
    Make a electrical ruler
    Make a electrical ruler
    Make a electrical ruler
    Make a electrical ruler
    Make a electrical ruler
    Make a electrical ruler
    Show All 7 Items

    when I start measure at 90mm,finish measure at 0mm,the OLED show measurement result is 90.0mm,and when I start measure at 0mm,turn back it to 90mm,the OLED show measurement result is -90.0mm.

    you can switch the result unit as:mm,cm,m and km

    I define a double variable to save measurement result,so,the limit is 1.79769e+308 ~ 2.22507e-308 mm

    I use this ruler to measure a bottle perimeter,OLED show -140.1mm,I think this bottle perimeter maybe is 140mm.

    sorry for my bad english .I want to make some friends.

    Source code and PCB files please mail to me satelives@gmail.com.

    Thanks!

  •  
     

    Tag cloud

    make build easy simple arduino making homemade solar laser printed portable cheap mini building custom cardboard wooden create super lego turn paracord chocolate your paper light intel