Connecting the Clay MCP to Arduino Hardware

Connect the Arduino

An Arduino is a small, cheap circuit board with a chip on it that can run a simple program and control real electronics: light up an LED, read a button, drive a screen. The one used here is called an Uno. Before you can wire anything to it or send it code, it has to be plugged into your computer over a USB cable, the same as any other USB device.

Connect to Clay

The other half of the setup is on Claude's side: it needs Clay's search tools available before it can look anything up. Adding the MCP server is what brings those tools into the conversation.

$ claude mcp add clay

Wire the LCD

An LCD screen like this has 16 metal pins sticking out the back, and each one has a different job: power, ground, adjusting contrast, and so on. Most of those are already wired up for you. The six pins below are the only ones you need to connect yourself. They carry the actual data that tells the screen what letters to show.

LiquidCrystal lcd(rs, enable, d4, d5, d6, d7);
LiquidCrystal lcd(7,  8,      9,  10, 11, 12);

#include <LiquidCrystal.h>
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);

void setup() {
  lcd.begin(16, 2);
  lcd.print("LCD OK");
}

void loop() {
  lcd.clear();
  lcd.print("Rows: " + String(counter++));
  delay(1000);
}

Adjust the contrast

Before any code matters, the screen needs contrast voltage on pin V0. Too little and the text is invisible; too much and every pixel goes solid. Drag the knob and find the window where it actually reads.

Diagnose the ghost signal

The wiring below looks identical to stage 03 (every pin lands where it should), but the screen is rotating through garbage on its own. That's not a wiring mistake, it's a bad connection. Disturb one wire at a time and watch for a reaction.

Click a wire to gently wiggle its connection. Most won't do anything: a solid connection doesn't react to being disturbed. One of them will visibly glitch the display. That's your culprit.

Connect the pipeline

Claude called Clay's search tools directly, then relayed the results to the physical board through a small file and a background process watching it. Five pieces, one order. Click them into place.