JM-01 AR

rev E-AR · screenless, the glasses are the display

40.0 × 16.6 × 5.0 cm packed arch left, grip bay right ≈ 1.15 kg, estimated

about ↗

Type on your keyboard to use its shell; ↑ ↓ turn the knob through history. Click the toggles.

Parts

Inside

Raspberry Pi Compute Module 5, 8 GB, under the left control panel behind the dial: face-down on the aluminium floor, on a 4.6 × 5.8 cm carrier with the 2230 NVMe SSD stacked on its top, and short leads to the back ports
Two flat LiPo pouch cells (~70 Wh) side by side in one 7 mm layer under the keyboard, on an insulating sheet over the aluminium floor, with room to swell; BMS and fuel gauge behind them
Keyboard PCB with a QMK controller, which also reads the thumbstick (two analog axes and a click) as a mouse
1.02 in e-ink status panel on the CM5's SPI bus, which it shares with the LoRa module; about 1 mm thick, it sits just under the top shell
No USB hub: the carrier's two USB 3 ports go to the back sockets, its two USB 2 ports to the keyboard and the SDR
RTL-SDR v4 dongle, blower, LoRa module, UPS and charging board in one row along the back, beside the port jacks rather than in front of them; the SDR lies sideways, with a short pigtail to the back SMA jack
SX1262 LoRa module on the GPIO pins (SPI) for Meshtastic, in the back row, its coax running to the right whip
Video bridge: an HDMI-to-DisplayPort converter and a USB-C mux and power chip on one small board, with the glasses' USB-C socket on its back edge. It takes the CM5's HDMI 0 and one USB 3 port, so the glasses get video, power and USB down one cable. HDMI 1 still goes to the back HDMI jack
WM8960 audio codec (speaker, mic and the voice radio's audio), and the slim 40 × 20 mm speaker facing the front grille
SA818 70 cm voice module under the palm rest, ahead of the battery; PTT and its settings on GPIO pins, coax to the left whip
Flat 30 mm blower aimed at the back vents, on the carrier's fan header so its speed follows the temperature
microSD extension and power-button lead from the carrier to the back edge
RTC coin cell (20 mm), and short panel-mount leads to every port, with a 2 cm strip behind the back edge kept clear for their jacks

Spec

Compute: Raspberry Pi Compute Module 5, 8 GB, on a slim carrier with an NVMe SSD
Display: None on the deck. AR glasses (XREAL Air type) on the back USB-C: 1080p per eye, DisplayPort over USB-C from the internal video bridge. Head tracking through the open-source XRLinuxDriver, which supports ARM64 (not yet tried on a CM5). Plus a 1.02 in e-ink status panel (128 × 80) behind the dial
Input: 60% low-profile; a sealed thumbstick on the left, with three click buttons under the space bar; an illuminated rotary dial and four lit-tip toggles, which are also the status lights
Radio: LoRa 868/915 MHz on the right whip; 70 cm voice, 1 W, push-to-talk and APRS, on the left whip; RTL-SDR (receive only) on the back SMA jack
Wireless: The CM5's Wi-Fi and Bluetooth, on an external antenna tucked inside the plastic top shell, away from the aluminium
Ports: USB-A and USB-C (both USB 3, straight off the carrier), HDMI, Ethernet, USB-C PD in, SMA, 3.5 mm audio, microSD, Qwiic (I2C), power button
Audio: WM8960 codec, small front speaker, pinhole mic, 3.5 mm headset jack
Cooling: Aluminium bottom shell as heatsink, CM5 face-down on a thermal pad, 30 mm blower, intake under the front lip, exhaust through the back edge
Power: 2 LiPo pouch cells, ≈ 70 Wh (about 63 usable), under the 100 Wh carry-on limit. Estimated: ~7.5 h writing with the glasses on (they draw about what the screen did), ~5 h on the SDR or compiling, ~18 h as a screen-off mesh node. The voice radio draws ~5 W only while you hold the PTT
Kit: Neoprene rain sleeve
Size: 40.0 × 16.6 × 5.0 cm packed. A 2° wedge, thin at the front and a little taller at the back
Weight: ≈ 1.15 kg, estimated, plus about 75 g of glasses, with a 2 mm aluminium bottom shell
Carry: Two-point sling, sideways across the back. Swing it round and a waist strap holds it level.

The AR edition of JM-01 rev E: no screen, no lid, the glasses are the display. Without a screen to hold, the top is one flat plane, the battery moves under the keyboard, the CM5 under the left panel, the status lights into the controls, and everything else lines up beside the port jacks, so the back edge comes 6.5 cm closer: only 3.4 cm are left behind the keys. Rev E itself is rev D made thinner: the body itself is the wedge, with flat pouch cells and a Compute Module 5 inside. Rev D made the rev B croquis asymmetric: an arch handle over the controls on the left, an open grip bay on the right. Sizes, weight and runtime are estimates. Written up on jeromem.dev.