Customization Possibilities

Customization Possibilities

Overview

This section covers how the factory display project can be customized for different buyer requirements. As a pre-sales engineer, you need to quickly assess which customizations are feasible, estimate the effort involved, and provide accurate guidance to buyers. After completing this section, you will be able to:

• Identify common customization paths for the e-paper display project
• Estimate effort and complexity for each customization
• Guide buyers toward feasible customizations
• Identify when a customization requires a fundamentally different solution

Common Customization Paths

Quick Reference Matrix

Customization	Effort	Complexity	Cost Impact	Feasibility
Different display size	Low	Simple	+$5-30	✅ Easy
Custom background image	Low	Simple	None	✅ Easy
Different data source	Medium	Moderate	None	✅ Feasible
Multi-page display	Medium	Moderate	None	✅ Feasible
Touch input integration	High	Complex	+$10-20	⚠️ Conditional
Tri-color display	Medium	Moderate	+$5-10	✅ Feasible
Larger text / higher contrast	Low	Simple	None	✅ Easy
Weatherproof enclosure	Medium	Moderate	+$20-50	✅ Feasible
Solar charging	High	Complex	+$15-30	⚠️ Requires planning
Real-time updates (< 1 min)	⚠️	N/A	N/A	❌ Not possible
Video playback	⚠️	N/A	N/A	❌ Impossible

Customization Detail

1. Different Display Size

Buyer Request: “I need a larger display that workers can read from 10 meters away.”

Options:

Size	Resolution	Readability	Cost	Best For
1.54”	200×200	Close range (1-2m)	$10-12	Desktop status indicators
2.13”	250×122	Moderate (2-3m)	$12-18	Recommended — balanced
2.9”	296×128	Readable (3-4m)	$15-22	Shelf labels
4.2”	400×300	Good (4-6m)	$25-35	Factory KPI boards
5.83”	648×480	Very good (6-8m)	$35-45	Meeting room schedules
7.5”	800×480	Excellent (8-10m)	$40-55	Large notice boards

Implementation Changes:

// Change only the constructor — the rest of the code stays the same
// For 4.2" display:
GxEPD2_BW<GxEPD2_420, GxEPD2_420::HEIGHT> display(
    GxEPD2_420(EPD_CS, EPD_DC, EPD_RST, EPD_BUSY)
);

// Adjust font sizes for readability
// 4.2" can use larger fonts
display.setFont(&FreeMonoBold24pt7b);  // 24pt instead of 18pt

Effort: ~1 hour — update constructor, adjust positions, re-test

2. Custom Background and Branding

Buyer Request: “We want our company logo and a custom layout on the display.”

Options:

• Company logo in the header
• Custom color scheme (limited to black/white/red)
• Branded border design
• Sectioned layout with company colors

Implementation:

// 1. Create background image with company logo + layout
// 2. Convert to XBM format (see 02-05)
// 3. Display once as background
// 4. Overlay dynamic text on top

void setup() {
    display.fillScreen(GxEPD_WHITE);

    // Draw branded background (only needs to happen once per deployment)
    display.drawInvertedBitmap(0, 0, company_background,
                                display.width(), display.height(),
                                GxEPD_BLACK);

    // Overlay dynamic data
    display.setFont(&FreeMonoBold12pt7b);
    display.setCursor(BRANDED_X, BRANDED_Y);
    display.print(sensorValue);

    display.display();
}

Effort: 2-4 hours — requires design work, image conversion, layout adjustments

3. Multi-Page Display

Buyer Request: “We want to cycle through different data pages — one for production, one for quality, one for safety.”

Implementation:

// Each page is a different screen layout
// The display cycles through pages on each refresh

RTC_DATA_ATTR int currentPage = 0;  // Persists across deep sleep

void setup() {
    // ... WiFi and MQTT setup ...

    // Display current page
    switch (currentPage) {
        case 0:
            showProductionPage();
            break;
        case 1:
            showQualityPage();
            break;
        case 2:
            showSafetyPage();
            break;
    }

    // Advance to next page for next wake cycle
    currentPage = (currentPage + 1) % 3;  // 3 pages

    // Store in RTC memory — survives deep sleep
}

void showProductionPage() {
    display.fillScreen(GxEPD_WHITE);
    display.setFont(&FreeMonoBold12pt7b);
    display.setCursor(5, 20);
    display.print("PRODUCTION");
    display.setFont(&FreeMonoBold24pt7b);
    display.setCursor(5, 60);
    display.print(unitsProduced);
    display.display();
}

Effort: 4-8 hours — design each page layout, implement cycling logic, test transitions

4. Tri-Color Display Upgrade

Buyer Request: “We want red text for alerts or exceeding thresholds.”

Implementation:

Hardware Change:

Wavehare 2.13" B/W → Wavehare 2.13" B/W/R (black/white/red)

Software Change:

// Include tri-color library
#include <GxEPD2_3C.h>

// Use tri-color constructor
GxEPD2_3C<GxEPD2_213_Z19c, GxEPD2_213_Z19c::HEIGHT> display(
    GxEPD2_213_Z19c(EPD_CS, EPD_DC, EPD_RST, EPD_BUSY)
);

void setup() {
    display.init(115200);

    // Draw using three colors
    display.fillScreen(GxEPD_WHITE);

    display.setTextColor(GxEPD_RED);  // Alert values in red
    display.setCursor(10, 30);
    display.print("CRITICAL");

    display.setTextColor(GxEPD_BLACK);  // Normal values in black
    display.setCursor(10, 60);
    display.print("Temperature: 25.5C");

    display.display();
}

Trade-off Warning:

⚠️ Tri-color displays have:
  - 3-5x slower refresh (15 seconds vs 3 seconds)
  - Lower contrast in black/white areas
  - Higher power consumption per refresh
  - No partial refresh support (full refresh only)

Recommend using tri-color only if red highlighting is essential.

Effort: ~2 hours — hardware swap, library change, color logic update

5. Alert Triggering with Node-RED

Buyer Request: “When a value exceeds a threshold, the display should show an alert.”

Implementation in Node-RED:

// Function node — threshold detection
const temperature = parseFloat(msg.payload.temperature);

if (temperature > 30) {
    // Send alert payload
    msg.payload = JSON.stringify({
        alert: true,
        message: "HIGH TEMP ALERT: " + temperature + "°C",
        bg_color: "RED",
        timestamp: new Date().toISOString()
    });
} else {
    // Send normal payload
    msg.payload = JSON.stringify({
        alert: false,
        temperature: temperature,
        humidity: msg.payload.humidity,
        timestamp: new Date().toISOString()
    });
}

return msg;

On ESP32 side:

void processMQTTMessage(const char* json) {
    JsonDocument doc;
    deserializeJson(doc, json);

    bool alert = doc["alert"] | false;

    if (alert) {
        // Show alert screen
        display.fillScreen(GxEPD_WHITE);
        display.setFont(&FreeMonoBold12pt7b);
        display.setTextColor(GxEPD_BLACK);

        // Draw alert border
        display.drawRect(2, 2, display.width()-4, display.height()-4, GxEPD_BLACK);

        const char* message = doc["message"] | "ALERT";
        display.setCursor(10, 40);
        display.print(message);
    } else {
        // Show normal display
        showNormalDisplay(doc);
    }
}

Effort: 2-4 hours — Node-RED logic + display handler

6. Data History Display

Buyer Request: “Show a mini chart of the last 24 hours of temperature data.”

Implementation: Since e-ink cannot render complex charts well, use a simplified approach:

// Simplified mini bar chart
void drawMiniChart(int x, int y, int width, int height, float* values, int count) {
    float minVal = 20, maxVal = 30;  // Known range for temperatures

    int barWidth = width / count;

    for (int i = 0; i < count; i++) {
        int barHeight = map((values[i] - minVal) * 10, 0, (maxVal - minVal) * 10, 0, height);
        int barX = x + i * barWidth;
        int barY = y + height - barHeight;

        display.fillRect(barX, barY, barWidth - 1, barHeight, GxEPD_BLACK);
    }
}

Effort: 4-8 hours — data aggregation in Node-RED, chart rendering, display optimization

7. Secure IoT Configuration (MQTT with TLS)

Buyer Request: “We need encrypted communication for data security.”

Refer to Chapter 16 (MQTT Security with TLS) for complete implementation.

Summary for e-paper context:

• MQTT over TLS adds ~2-3 seconds to connection time
• Requires ~5KB additional firmware space for certificates
• Increases active power consumption slightly due to TLS handshake
• ESP32 supports TLS natively — no additional hardware needed

Effort: 4-8 hours — certificate generation, firmware update, testing

Cost Impact Analysis

Customization	Hardware Cost Δ	Dev Effort	Maintenance Δ
2.13” → 7.5” display	+$30-40	Low	None
B/W → Tri-color	+$5-10	Low	None
Touch screen add-on	+$15-25	High	Higher
Solar charging	+$15-30	Medium	Annual battery check
Weatherproof IP65	+$20-50	Medium	Seal inspection
TLS encryption	None	Medium	Certificate renewal
Multi-page display	None	Medium	None
Custom enclosure	+$10-50+	High	Custom parts

When to Recommend an Alternative Solution

Sometimes e-ink is not the right choice. Recommend alternatives when:

Requirement	Better Alternative	Reason
Real-time updates (< 1 min)	LCD + wired power	E-ink refresh too slow
Full color, video, animation	Tablet (Android/iPad)	E-ink limited to 2-3 colors
Touch interaction	Capacitive touch LCD	E-ink lacks responsive touch
Very large display (> 32”)	Commercial display screen	E-ink too expensive at large sizes
Audio alarms	Add buzzer module	E-ink displays no audio
Camera image display	Security monitor system	E-ink cannot show camera feeds

Summary

1. Most customizations are feasible — display size, branding, data sources, multi-page
2. Tri-color upgrade is possible but has significant refresh speed trade-offs
3. Real-time updates and video are fundamentally impossible on e-ink — recommend alternatives
4. Custom enclosure design is often the longest-lead-time item — plan ahead
5. TLS and MQTT security are fully supported on ESP32 but add connection overhead
6. Always test customizations in the target environment before committing to a buyer

References

• Waveshare E-Paper Display Range
• Seeed Studio XIAO ESP32-C3 Battery Options
• IP Rating Reference Guide

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Target Audience: Alibaba.com IoT Pre-sales Engineers
Status: ✅ Completed