The “Chance PI” metal detector uses the 1602 LCD display. We will connect the display to the microcontroller on the board via a 4-bit parallel interface.
I will reproduce part of the scheme with the connection of the display.
You can use a cable from the HDD drive as the wires for connecting the display, its pin header just went in a step with a pin header on the display. The display has 16 Pins that are numbered and signed.
We connect the second end of the nape to the “Chance” board. In the picture highlighted in red, where to connect each wire from the display. The numbers in parentheses are the contact numbers of the display 1602.
” LCD- (1, 5) ” and ” LCD + (2) ” are the power of the display.
” LED- (16) ” and ” LED + (15) ” – the power of the display backlight.
The display contrast is set by a 22kΩ trimmer. On the metal detector board there is no this resistor, it must be soldered between the 3rd contact of the display and the ground. I set the necessary contrast for myself, then I measured the resistance and soldered the trimmer into place, the fixed resistor of the required rating, in my case it is 4.7 kΩ.
After connecting the display, connect the block of buttons.
Metal detector “Chance PI ” with a connected display 1602 and a block of buttons.
We connect the power supply of 12 volts to the contacts “BATT + 1” and “BATT-1”, observing the polarity is important to avoid damaging board.
With the proper installation, electronic components and microcontroller firmware, the metal detector should display on the display the web address of the chance PI author and the installed firmware version .
Next step, the working interface will be displayed, when you click on the buttons, you can edit the device operation parameters.