The Pico W has a relatively small amount of memory and DVI output and WiFi need a lot of it. As a result, this project is coded up using Arduino. You'll need to install the necessary libraries and add your WiFi and Adafruit IO credentials to the config.h file before uploading the code to your Pico W with the Arduino IDE.
Install the Libraries
You can install the libraries for this project using the Library Manager in the Arduino IDE.
Click the Manage Libraries... menu item, search for Adafruit PicoDVI, and select the PicoDVI - Adafruit Fork library:
If asked about dependencies, click "Install all".
Then install the Adafruit IO Arduino library. Click the Manage Libraries... menu item again, search for Adafruit IO, and select the Adafruit IO Arduino library:
If asked about dependencies, click "Install all".
Code Prep
The code consists of a main .ino program file and two header files. config.h configures your WiFi and Adafruit IO connection. sprites.h stores the graphics for the project. You'll need all three of these files to properly compile and run the project. These files are available in the .ZIP folder below or on GitHub.
// SPDX-FileCopyrightText: 2024 Liz Clark for Adafruit Industries
//
// SPDX-License-Identifier: MIT
/************************** Configuration ***********************************/
// edit the config.h tab and enter your Adafruit IO credentials
// and any additional configuration needed for WiFi, cellular,
// or ethernet clients.
#include "config.h"
#include "sprites.h"
#include <PicoDVI.h> // Core display & graphics library
#include <Fonts/FreeSansBold18pt7b.h> // A custom font
#include <Fonts/FreeSans9pt7b.h> // A custom font
// put your four feed names here!
AdafruitIO_Feed *temp = io.feed("temperature-feed");
AdafruitIO_Feed *humid = io.feed("humidity-feed");
AdafruitIO_Feed *bat = io.feed("battery-feed");
AdafruitIO_Feed *aqi = io.feed("aqi-feed");
#define IO_LOOP_DELAY 5000
unsigned long lastUpdate = 0;
float temp_data;
float humid_data;
int bat_data;
int aqi_data;
struct outline {
int16_t x, y; // Top-left corner
};
outline greenOutline = {159, 35};
outline yellowOutline = {204, 35};
outline redOutline = {250, 35};
DVIGFX8 display(DVI_RES_320x240p60, false, adafruit_dvibell_cfg);
void setup() {
// start the serial connection
Serial.begin(115200);
// wait for serial monitor to open
//while ( !Serial ) delay(10);
Serial.print("Connecting to Adafruit IO");
// start connection to io.adafruit.com
io.connect();
// set up a message handler for the count feed.
// the handleMessage function (defined below)
// will be called whenever a message is
// received from adafruit io.
temp->onMessage(tempMessage);
humid->onMessage(humidMessage);
bat->onMessage(batMessage);
aqi->onMessage(aqiMessage);
// wait for a connection
while(io.status() < AIO_CONNECTED) {
Serial.print(".");
delay(500);
}
// we are connected
Serial.println();
Serial.println(io.statusText());
// Because Adafruit IO doesn't support the MQTT retain flag, we can use the
// get() function to ask IO to resend the last value for this feed to just
// this MQTT client after the io client is connected.
temp->get();
humid->get();
bat->get();
aqi->get();
Serial.println("starting picodvi..");
if (!display.begin()) { // Blink LED if insufficient RAM
pinMode(LED_BUILTIN, OUTPUT);
for (;;) digitalWrite(LED_BUILTIN, (millis() / 500) & 1);
}
Serial.println("picodvi good to go");
// Set up color palette
display.setColor(0, 0x0000); // black
display.setColor(1, 0x057D); // blue
display.setColor(2, 0xB77F); // light blue
display.setColor(3, 0xE8E4); // red
display.setColor(4, 0x3DA9); // green
display.setColor(5, 0xFF80); // yellow
display.setColor(6, 0xFFFF); // white
}
void loop() {
// io.run(); is required for all sketches.
// it should always be present at the top of your loop
// function. it keeps the client connected to
// io.adafruit.com, and processes any incoming data.
io.run();
if (millis() > (lastUpdate + IO_LOOP_DELAY)) {
display.fillScreen(0);
display.drawBitmap(38, 35, airBitmap, airWidth, airHeight, 2);
display.drawBitmap(47, 132, tempBitmap, tempWidth, tempHeight, 3);
display.drawBitmap(145, 132, waterBitmap, waterWidth, waterHeight, 1);
display.drawBitmap(248, 132, batBitmap, batWidth, batHeight, 6);
drawBatterySquare(bat_data);
displayAQI(aqi_data);
display.setFont(&FreeSansBold18pt7b);
display.setTextColor(6);
display.setCursor(38 + airWidth + 15, 38 + airHeight - 10);
display.println(aqi_data);
display.setFont(&FreeSans9pt7b);
display.setCursor(47 - 9, 130 + tempHeight + 25);
display.print(temp_data, 2);
display.println(" F");
display.setCursor(145 - 9, 130 + tempHeight + 25);
display.print(humid_data, 2);
display.println("%");
display.setCursor(248 - 5, 130 + tempHeight + 25);
display.print(bat_data);
display.println("%");
// store the current time
lastUpdate = millis();
}
}
void humidMessage(AdafruitIO_Data *data) {
//Serial.print("received <- ");
Serial.println(data->value());
String h = data->value();
humid_data = h.toFloat();
}
void tempMessage(AdafruitIO_Data *data) {
//Serial.print("received <- ");
Serial.println(data->value());
String d = data->value();
temp_data = d.toFloat();
}
void batMessage(AdafruitIO_Data *data) {
//Serial.print("received <- ");
Serial.println(data->value());
String b = data->value();
bat_data = b.toInt();
}
void aqiMessage(AdafruitIO_Data *data) {
//Serial.print("received <- ");
Serial.println(data->value());
String a = data->value();
aqi_data = a.toInt();
}
void displayAQI(int data) {
display.fillRoundRect(164, 40, 30, 30, 4, 4);
display.fillRoundRect(209, 40, 30, 30, 4, 5);
display.fillRoundRect(255, 40, 30, 30, 4, 3);
if (data <= 12) { // Good
display.drawRoundRect(greenOutline.x, greenOutline.y, 40, 40, 4, 6);
} else if (data <= 35) { // Bad
display.drawRoundRect(yellowOutline.x, yellowOutline.y, 40, 40, 4, 6);
} else { // Dangerous
display.drawRoundRect(redOutline.x, redOutline.y, 40, 40, 4, 6);
}
}
void drawBatterySquare(int data) {
int BASE_SQUARE_X = 252; // Base X position
int BASE_SQUARE_Y = 140; // Base Y position
int SQUARE_WIDTH = 21; // Width is constant
int MAX_SQUARE_HEIGHT = 35; // Maximum height for 100% charge
// Map battery percentage to square height
int height = map(data, 0, 100, 0, MAX_SQUARE_HEIGHT);
// Choose color based on battery percentage
uint16_t color;
if (data >= 70) {
color = 4;
} else if (data >= 40) {
color = 5;
} else {
color = 3;
}
// Calculate Y position based on height to draw from bottom up
int yPos = BASE_SQUARE_Y + (MAX_SQUARE_HEIGHT - height);
// Draw the battery square
display.fillRect(BASE_SQUARE_X, yPos, SQUARE_WIDTH, height, color);
}
After downloading the files and opening them in the Arduino IDE, navigate to the config.h file. At the top replace the following variables with your connection information:
-
IO_USERNAMEwith your Adafruit IO username -
IO_KEYwith your Adafruit IO key -
WIFI_SSIDwith your WiFi SSID name -
WIFI_PASSwith your WiFi SSID password
If you don't put your information in the config.h file, you won't be able to connect to WiFi or Adafruit IO!
The main code file connects to four different Adafruit IO feeds to pull data to display. You can update the feed names at the top of the file:
After updating the files with your information, you can upload the code to your Pico W. It takes a few seconds to establish the connection with Adafruit IO, but after that you should see the data and graphics displayed thru the DVI output on the PiCowbell.
Page last edited January 19, 2025
Text editor powered by tinymce.
