Main processor, ATSAMD51J20 Cortex M4, 120MHz with 3.3V logic/power per Adafruit Learn pinouts page.
ESP32 WiFi co-processor SPI chip-select, documented as board.ESP_CS / Arduino 8.
ESP32 WiFi co-processor ready/busy pin, documented as board.ESP_BUSY / Arduino 5.
ESP32 WiFi co-processor reset pin, documented as board.ESP_RESET / Arduino 7.
UART connection to ESP32 WiFi co-processor, documented as board.ESP_RX.
UART connection to ESP32 WiFi co-processor, documented as board.ESP_TX.
microSD card SPI chip-select, documented as board.SD_CS / Arduino 32.
microSD card detect pin, documented as board.SD_CARD_DETECT / Arduino 33.
DAC0 analogue output feeding the onboard speaker amplifier, documented as board.AUDIO_OUT / Arduino A0.
Speaker amplifier shutdown/enable pin, documented as board.SPEAKER_ENABLE / Arduino 50.
4-pin JST I2C connector for external I2C sensors; Adafruit notes the 5V3 jumper must be set to 3V for SAMD51-safe pullups.
Ambient light sensor analogue input, documented as board.LIGHT / Arduino A2.
Resistive touchscreen YD connection, documented as board.TOUCH_YD / Arduino A4.
Resistive touchscreen XL connection, documented as board.TOUCH_XL / Arduino A5.
Resistive touchscreen YU connection, documented as board.TOUCH_YU / Arduino A6.
Resistive touchscreen XR connection, documented as board.TOUCH_XR / Arduino A7.
TFT reset control, documented as board.TFT_RESET / Arduino 24.
TFT write control, also TFT data/command pin in SPI mode, documented as board.TFT_WR or board.TFT_DC / Arduino 25.
TFT read control, documented as board.TFT_RD / Arduino 9.
TFT register-select control, documented as board.TFT_RS / Arduino 10.
TFT chip-select control, documented as board.TFT_CS / Arduino 11.
TFT tearing-effect signal, documented as board.TFT_TE / Arduino 12.
PWM-controllable TFT backlight transistor connection, documented as board.TFT_BACKLIGHT / Arduino 25.
| Pin | Position | Type | Function | Voltage |
|---|---|---|---|---|
| ATSAMD51J20 | mcu | Main processor, ATSAMD51J20 Cortex M4, 120MHz with 3.3V logic/power per Adafruit Learn pinouts page. | 3.3V logic/power | |
| ESP_CS | digital | ESP32 WiFi co-processor SPI chip-select, documented as board.ESP_CS / Arduino 8. | 3.3V logic | |
| ESP_BUSY | digital | ESP32 WiFi co-processor ready/busy pin, documented as board.ESP_BUSY / Arduino 5. | 3.3V logic | |
| ESP_RESET | digital | ESP32 WiFi co-processor reset pin, documented as board.ESP_RESET / Arduino 7. |
SPI · I2C · 3.3 V · 3.3 – 5 V · Breakout
Adafruit describes product 398 as a 16x2 RGB backlight LCD using digital pins for LCD control and PWM pins for the backlight; the product…
Module pins: ESP_RX, ESP_TX, SD_CS, AUDIO_OUT, STEMMA I2C, LIGHT, TOUCH_YD, TOUCH_XL. Schematik maps them to your board in the app.
16×2 and 20×4 character LCDs (parallel, I2C backpack, Qwiic, Grove), SPI TFTs from 0.71 to 3.5 inches, and large DSI and HDMI capacitive-touch panels up to 13.3 inches.
I2C 20x4 Arduino LCD Display Module visual previewI2C 20x4 Arduino LCD Display Module
20x4 I2C character LCD. Use when the project needs four lines; not a drop-in for a 16x2 enclosure or layout.
Standard LCD 16x2, white on blue visual previewStandard LCD 16x2, white on blue
RGB Backlight Positive LCD 16x2 visual previewRGB Backlight Positive LCD 16x2
Bare 16x2 character LCD with RGB backlight. Good when the design expects direct LCD wiring and controls the RGB backlight pins itself.
SparkFun 16x2 SerLCD - RGB Backlight (Qwiic) visual previewSparkFun 16x2 SerLCD - RGB Backlight (Qwiic)
16x2 RGB character LCD with Qwiic serial control. Same display size as many 16x2 modules, but a different wiring and software path.
Gravity: I2C 16x2 Arduino LCD with RGB Backlight Display V2.0 visual previewGravity: I2C 16x2 Arduino LCD with RGB Backlight Display V2.0
16x2 Gravity I2C RGB LCD. Similar purpose to other 16x2 I2C displays, but connector ecosystem and board size still matter.
I2C RGB Backlight LCD 16x2 Display Module for Arduino (Black Text) visual previewI2C RGB Backlight LCD 16x2 Display Module for Arduino (Black Text)
16x2 I2C RGB LCD with a larger module footprint than some compact 16x2 backpacks. Check mounting and address before swapping.
Grove - 16x2 LCD - White on Blue visual previewGrove - 16x2 LCD - White on Blue
Grove 16x2 display module. Grove connector makes it convenient in Grove systems, not automatically drop-in for Qwiic or bare parallel LCD wiring.
Grove - 16x2 LCD - Black on Red visual previewGrove - 16x2 LCD - Black on Red
Grove 16x2 display with a different backlight/color variant. Treat as same Grove display class, then verify exact SKU and stock.
Grove - 16x2 LCD - Black on Yellow visual previewGrove - 16x2 LCD - Black on Yellow
Grove 16x2 display color variant. Functionally adjacent to the other Grove 16x2 rows, but not proof of identical module electronics.
Red/Black/White Inky pHAT (ePaper/eInk/EPD) visual previewRed/Black/White Inky pHAT (ePaper/eInk/EPD)
Pimoroni Inky pHAT e-paper module sold by Kiwi. Best treated as a Raspberry Pi pHAT display with e-paper-specific refresh and library checks, not a generic display panel.
Adafruit RGB Positive 16x2 LCD+Keypad Kit for Raspberry Pi visual previewAdafruit RGB Positive 16x2 LCD+Keypad Kit for Raspberry Pi
SparkFun TFT LCD Breakout - 1.8" (128x160) visual previewSparkFun TFT LCD Breakout - 1.8" (128x160)
1.8 inch 128x160 color TFT breakout. Use when the design expects a small SPI-style graphics display, not as a character LCD replacement.
1.02" E-Ink Display Module - 128x80, Black/White, SPI visual preview
1.02" E-Ink Raw Display Panel - 128x80, Black/White, SPI visual preview
1.54inch e-Paper Module (B), 200×200, 3-Color, SPI visual preview
1.54inch e-Paper Module, 200×200, SPI visual previewWaveshare makes up the large majority of parts here and often sells the same panel twice: once as a raw display needing a separate driver board, and once as a module or HAT+ with the SPI controller attached.
Displays · E-paper displays · 102 parts
"Shake" 8x8 LED Matrix visual preview
10-Segment LED Bar Graph - Red visual preview
11x1 VFD Display Module visual preview
11x7 LED Matrix Breakout visual previewAdafruit HT16K33 backpacks, MAX7219 daisy-chains, NeoPixel and DotStar grids, HUB75 RGB matrix panels, charlieplexed arrays, bare clock displays, and two VFD character modules — almost 90 parts, none wired the same way.
Displays · LED displays · 88 parts
0.49inch OLED Display Module, 64×32, I2C visual preview
0.91" OLED Display Module - 128x32, I2C visual preview
0.96" OLED (B) - SPI/I2C visual preview
0.96" RGB OLED Display Module - 64x128, SPI, 65K Colors visual previewAbout 30 parts: monochrome I2C modules from 0.49 to 1.3 inches, SPI/I2C grayscale and 65K-color RGB panels up to 1.5 inches, a transparent OLED, and ecosystem-specific units for Raspberry Pi, FireBeetle and M5Stack Grove.
Displays · OLED displays · 29 parts
1.75mm PLA (1kg) - Black visual preview
1.75mm PLA (1kg) - Gold visual preview
1.75mm PLA (1kg) - Green visual preview
1.75mm PLA (1kg) - Natural visual previewDFRobot 1.75 mm PLA in 1 kg spools makes up the bulk of the group, in over 15 colors. Specialty options include PVA in both diameters, NinjaFlex flexible filament, Proto-Pasta conductive PLA, and wood-fill. OverLord printer spares and OverLord printers round out the hardware side.
Tools & prototyping · 3D printing · 53 parts
| 3.3V logic |
| ESP_RX | uart | UART connection to ESP32 WiFi co-processor, documented as board.ESP_RX. | 3.3V logic |
| ESP_TX | uart | UART connection to ESP32 WiFi co-processor, documented as board.ESP_TX. | 3.3V logic |
| SD_CS | spi | microSD card SPI chip-select, documented as board.SD_CS / Arduino 32. | 3.3V logic |
| SD_CARD_DETECT | digital | microSD card detect pin, documented as board.SD_CARD_DETECT / Arduino 33. | 3.3V logic |
| AUDIO_OUT | analog | DAC0 analogue output feeding the onboard speaker amplifier, documented as board.AUDIO_OUT / Arduino A0. | analogue output from SAMD51 DAC0 |
| SPEAKER_ENABLE | digital | Speaker amplifier shutdown/enable pin, documented as board.SPEAKER_ENABLE / Arduino 50. | 3.3V logic |
| STEMMA I2C | i2c | 4-pin JST I2C connector for external I2C sensors; Adafruit notes the 5V3 jumper must be set to 3V for SAMD51-safe pullups. | 3.3V I2C when 5V3 jumper is changed to 3V |
| LIGHT | analog | Ambient light sensor analogue input, documented as board.LIGHT / Arduino A2. | analogue input |
| TOUCH_YD | analog | Resistive touchscreen YD connection, documented as board.TOUCH_YD / Arduino A4. | analogue touch input |
| TOUCH_XL | analog | Resistive touchscreen XL connection, documented as board.TOUCH_XL / Arduino A5. | analogue touch input |
| TOUCH_YU | analog | Resistive touchscreen YU connection, documented as board.TOUCH_YU / Arduino A6. | analogue touch input |
| TOUCH_XR | analog | Resistive touchscreen XR connection, documented as board.TOUCH_XR / Arduino A7. | analogue touch input |
| TFT_RESET | display | TFT reset control, documented as board.TFT_RESET / Arduino 24. | 3.3V logic |
| TFT_WR / TFT_DC | display | TFT write control, also TFT data/command pin in SPI mode, documented as board.TFT_WR or board.TFT_DC / Arduino 25. | 3.3V logic |
| TFT_RD | display | TFT read control, documented as board.TFT_RD / Arduino 9. | 3.3V logic |
| TFT_RS | display | TFT register-select control, documented as board.TFT_RS / Arduino 10. | 3.3V logic |
| TFT_CS | display | TFT chip-select control, documented as board.TFT_CS / Arduino 11. | 3.3V logic |
| TFT_TE | display | TFT tearing-effect signal, documented as board.TFT_TE / Arduino 12. | 3.3V logic |
| TFT_BACKLIGHT | display | PWM-controllable TFT backlight transistor connection, documented as board.TFT_BACKLIGHT / Arduino 25. | backlight control signal |
