Portable Handheld Linux Terminal With 3.5inch Touch Display

The Waveshare PocketTerm35 turns a Raspberry Pi 4B or Pi 5 into a proper handheld Linux computer. A 3.5inch 640 × 480 optically bonded touchscreen sits above a 67-key QWERTY silicone keyboard, so you get a complete Linux desktop — terminal, editor, browser, development tools — in something that fits in a jacket pocket. A built-in RP2040 handles the keyboard, brightness and volume, and an on-board UPS lets it run from an internal battery or from USB-C without dropping the session.

Key Features

• Handheld Linux terminal built around a Raspberry Pi 4B or Pi 5 — a full desktop, not a thin client
• Dual input — 67-key QWERTY silicone keyboard plus 5-point capacitive touch
• 3.5inch 640 × 480 IPS display with optical bonding and a 6H toughened glass front
• Built-in UPS — charge and run at the same time, and switch between battery and external power without a reboot
• Gaming controls — D-pad, X/Y/A/B action keys, L/R shoulder buttons and Select/Start, so RetroPie works out of the box
• CNC-machined aluminium front cover with a PC + ABS back, at 93.5 × 168.5 × 37 mm
• Pi ports stay usable — Ethernet and USB are exposed on the side panel, and the 40-pin GPIO header is reachable through the back cover

Display and touch

The 3.5inch IPS panel runs at 640 × 480 over the Pi's HDMI output, with a 71.08 × 53.56 mm active area. Optical bonding (G + G) removes the air gap between the glass and the LCD, which cuts internal reflection and makes the screen far easier to read outdoors than a typical stacked panel. The 5-point capacitive touch layer talks to the Pi over I2C rather than USB, so it uses GPIO2, GPIO3 and GPIO4 — worth knowing if you plan to add other I2C peripherals.

Keyboard and controls

The 67-key silicone keyboard uses a standard QWERTY layout with a full number row, Tab, Caps, Ctrl, Alt, Shift, two Fn keys and a CMD key. Function keys F1–F12 and Esc, Ins, Del, Home, End, PgUp, PgDn and ScrLk are on the Fn layer. Above the keyboard are a four-way D-pad, X/Y/A/B action keys, L and R shoulder buttons, Select and Start, and a Caps Lock indicator LED.

The RP2040 handles these shortcuts in hardware, so they work regardless of what the Pi is running:

Fn + -

Reduce display brightness

Fn + =

Increase display brightness

Fn + C

Display sleep — turns the screen off and on

Fn + E

Reduce system volume

Fn + R

Increase system volume

Fn + W

Mute

Power and battery

A 3.7V 5000mAh polymer lithium battery is included and connects to the internal 2PIN PH2.0 header. The UPS circuit charges the battery and powers the Pi at the same time, so plugging in or unplugging USB-C never interrupts what you're doing. Four LEDs beside the screen show the charge level.

The top power button is short press to turn on and double press to turn off. Shut the operating system down in software first, then double-press to cut power. The battery bay suits a 67 × 55 × 12 mm cell, so a similarly sized replacement will fit if you ever need one.

Ports and interfaces

Outside: USB-C charging and power input, a 3.5mm headphone jack, the power button and the battery-level indicator LEDs along the top edge; BOOT and RESET buttons, the speaker grille and access to the Raspberry Pi's 40-pin GPIO header on the back; and the Pi's own Ethernet and USB ports brought out through the swappable side panel.

Inside, the baseboard exposes a 2PIN PH2.0 battery header, a 4PIN PH1.25 speaker header for the built-in 8Ω 2W speaker, a 4PIN PH1.25 keyboard header, a 20-pin HDMI FPC connector and spring-loaded pogo pins that pick up the touch I2C bus from the Pi's GPIO header.

2PIN PH2.0 battery header

BAT+, GND

4PIN PH1.25 keyboard header

1 USB-5V · 2 USB_D- · 3 USB_D+ · 4 GND

Touch pogo pins

TP_INT · TP_SCL · TP_SDA · GND · 5V · 5V

20-pin HDMI FPC connector

1 HOT_PLUG_DETECT · 2 HDMI-5V · 3 GND · 4 SDA · 5 SCL · 6 NC · 7 CEC · 8 CLOCK_N · 9 GND · 10 CLOCK_P · 11 DATA0_N · 12 GND · 13 DATA0_P · 14 DATA1_N · 15 GND · 16 DATA1_P · 17 DATA2_N · 18 GND · 19 DATA2_P · 20 GND

Space above the Raspberry Pi is tight — any add-on board has to sit within about 2.5 mm of the tallest component on the Pi. If you want M.2 storage on a Pi 5 build, Waveshare's PCIe to M.2 Board (E) is the one that fits; most other SSD adapters will not leave room for a fan.

Setting it up

Assembly is straightforward: remove the six back-cover screws, fit the micro HDMI and USB-C cables using the supplied adapters, seat the Pi on the standoffs so it makes contact with the pogo pins, secure it with four screws, connect the battery, fit the correct side panel for your board and close it up. Fit the Pi 4 or Pi 5 bracket to match your board — both are included — and use the silicone side button and black button cap on a Pi 5 build.

On the software side you can either flash Waveshare's pre-built PocketTerm35 image, or add four lines to config.txt on a stock Raspberry Pi OS install and drop in the supplied device tree overlay:

dtparam=i2c_arm=on
dtoverlay=waveshare-35dpi-4b
dtoverlay=waveshare-35dpi-5b
dtoverlay=dwc2,dr_mode=host

Two things worth knowing up front. If you're building on a Pi 5 and see an "insufficient current" warning, that's the Pi failing to detect a USB-C PD source — add PSU_MAX_CURRENT = 5000 via sudo rpi-eeprom-config --edit and reboot. And if the picture works but touch doesn't, check nothing else has claimed GPIO2, GPIO3 or GPIO4, and that the Pi's GPIO pins are seating cleanly on the pogo pins.

The full assembly walkthrough, software guide, image download and FAQ are on the Waveshare wiki — see the Resources section on this page.

Specifications

• Compatible boards: Raspberry Pi 4B or Raspberry Pi 5 (not included)
• MCU: RP2040, handling keyboard, brightness and volume
• Display: 3.5inch IPS, 640 × 480, driven over HDMI; 71.08 × 53.56 mm active area
• Touch: 5-point capacitive, optical bonding, G + G toughened glass, 6H hardness, I2C
• Audio: built-in 8Ω 2W speaker on a 4PIN PH1.25 header, plus 3.5mm output
• Keyboard: 67-key QWERTY silicone
• Power input: USB-C charging port
• Battery: 3.7V 5000mAh included, 2PIN PH2.0 header, 67 × 55 × 12 mm bay
• Power management: UPS, charge and run simultaneously
• Power control: short press to turn on, double press to turn off
• Materials: CNC-machined aluminium front cover, PC + ABS back cover
• Dimensions: 93.5 × 168.5 × 37 mm; 20 mm thick at the keyboard end; R6.5 mm corners

What's in the box

• PocketTerm35 main unit × 1
• Pi 4 side panel / bracket × 1
• Pi 5 side panel / bracket × 1
• Micro HDMI adapter × 1
• Type-C male to 4PIN PH1.25 female adapter × 1
• 1.27H 4PIN opposite-direction 15cm double-ended cable × 1
• 120mm HDMI cable × 1
• 3.7V 5000mAh polymer lithium battery with cable × 1
• Screw kit × 1
• Screwdriver × 1
• Pi 5 side silicone power button × 1
• Black power button cap × 1

You'll also need

• A Raspberry Pi 4 Model B or Raspberry Pi 5
• A microSD card for the operating system
• A low-profile heatsink or cooler to suit your board — remember the 2.5 mm clearance limit
• A USB-C power supply for charging (a 27W Raspberry Pi supply is ideal for a Pi 5 build)