e-badge

A reusable conference badge for the Pimoroni Badger 2040 running Badger OS. Three screens switchable with front buttons: A=badge, B=joke, C=QR vCard.

Switching conferences

Conference files contain a single line with the conference name. Personal info lives in personal.txt and is shared across conferences. To switch conference, copy the right file to badges/badge.txt on the device:

make upload-config CONF=myconference2026.txt

Create a new conference file:

echo "MyConference 2026" > myconference2026.txt
make upload-config CONF=myconference2026.txt

Config files

Personal info (personal.txt)

One value per line, shared across all conferences:

Line	Field
1	Your name
2	Detail 1 label (e.g. "Email:")
3	Detail 1 value
4	Detail 2 label (e.g. "IRC:")
5	Detail 2 value
6	Detail 3 label (e.g. "GitHub:")
7	Detail 3 value
8	Detail 4 label (e.g. "GitLab:")
9	Detail 4 value
10	Image path on device
11	Phone number

See example.personal.txt for a template.

Conference file

Single line with the conference name:

MyConference 2026

Details 1-2 (email, IRC) are shown on the badge screen. All details are shown on the QR screen and included in the vCard.

Jokes

Jokes are stored in jokes.txt, separated by --- on its own line. Each block is one joke with literal newlines for line breaks on screen.

Why do programmers
prefer dark mode?

Because light
attracts bugs.
---
There are 10 types
...

Upload jokes to the device:

uvx mpremote fs cp jokes.txt :/jokes.txt

If /jokes.txt is missing on the device, a built-in fallback list is used.

Uploading to the Badger 2040

Plug in the Badger via USB. Uses uvx to run mpremote without installing it globally.

# Check the device is visible
uvx mpremote connect list

# Upload badge app, image, jokes, and personal info
make upload-all

# Upload conference config
make upload-config CONF=myconference2026.txt

# Reset the device after uploading
make reset

# Or combine upload and reset
make upload-all reset

After uploading, the badge app appears in the Badger OS launcher.

Images

• Pre-size to 80x80 pixels or smaller before uploading.
• Use baseline JPEG (not progressive -- the decoder cannot handle it).
• Monochrome or greyscale images work best on the 1-bit display.
• Store images in /badges/ on the device.

Common issues

• Progressive JPEGs will fail silently or raise an exception.
• Large images eat RAM fast; keep them small.
• The mpremote fs cp command has a bug where it skips files with the same size. The Makefile works around this by deleting before copying.
• The device halts after drawing (power saving). Unplug and replug USB between commands if the device stops responding.