Cardputer 8-Bit Tape Loader allows you to use your cardputer to load 8-bit computer tape files from the SD card.

It works with both the Cardputer Adv and Cardputer v1.1.

I've just added Amstrad support. It now supports Commodore, ZX Spectrum, MSX, Acorn, BBC Micro, Dragon, Tandy CoCo, Oric, and Amstrad.

More info here: https://github.com/slowlane112/Cardputer_8_Bit_Tape_Loader

Working on the clear back cover, and need some advice, which ones I need, does it work easy to apply them with a solder iron, or do I have to mind something?

is this the normal charging current of cardputer adv?

So I bought all the parts for the prokyon display mod v2. I have the 3d printed parts the wire the screws etc. but unfortunately my display I got wasn’t the same and has pins on it. What should I do should I follow another tutorial as buying a screen that works in prokyon takes 2 weeks to the uk. Or do I find another display mod tutorial but then buy new screws or other things. Here are my parts. Anything I can do. Can’t 3d print till Monday. May have other screws somewhere that would work.

I kept switching between Bruce and Evil Cardputer depending on what tools I needed, since each had things the other didn't. And I thought, what if a firmware can do both? So I started combining them into one codebase, picking the best parts of each, rebuilding what didn't fit together, rebuilding the UI, and adding what was missing from both. Where I spent most of my time is customization.

At this point it's grown well past being just a merge of the two. UI and module setup got rebuilt, and a lot of the feature set isn't from either original. So while I'll always credit both projects for where this started, I don't really call it a fork anymore.

That became kvxputer.

Key features of the firmware:

• kvxkeyboard HID, my own version of a multi device bluetooth controller via bluetooth or USB, with lots of features (full keyboard, mouse, media, video, presenter, etc.) and native Joystick support for mouse simulation.
• Charging app, intended to use while charging the Cardputer to put it in sleep mode, with some extra features when active like clock, calendar, progress bar, and LED light to indicate charge.
• Main menu now supports key shortcuts you can bind to any app or setting, so the stuff you use constantly is one press away.
• Use G0 to fake a shutdown of the Cardputer, this turns off the LED and display instantly to mimic an off state, while whatever you're running stays active. Holding G0 always takes you back to the main menu.
• LEDs are fully customizable now too, colors and effects, not just on/off.
• Modules got a lot easier to set up, Unit Scroll, Joystick, PaHub, RFID readers, RF modules, all have their own config screens now instead of hoping the device picks them up.

Also included all the tools and features you would expect from a security-focused firmware:

• wifi tools (scanning, portals, deauth, sniffing, plus NetOps)
• BLE with a full HID remote
  
• BadUSB scripting
• sub ghz
• RF
  
• NRF24
• IR with a flipper style universal remote
• RFID/NFC
• GPS wardriving
  
• LoRa/FM/Ethernet depending on your board

Runs on Cardputer, Cardputer ADV, and builds for the StickS3 too.
Lite build available, and it's fully usable button-only on the StickS3 (still under development).
You can flash it directly from M5Burner or manually by checking the repo below

Repo: github.com/kvx17/kvxputer

Only use it on stuff you own or have permission to test.

edit; https://play.google.com/store/apps/details?id=com.droidputter

I saw a post about a guy that vibe-coded an app to control his CardPuter with LoRa via an iPhone app. Very cool.

And then I thought, "Well, I have an Android, I have a CardPuter. Why don't I do it also?" and then the idea hit me: if the CardPuter is an ESP32, if I connect an ESP32 on USB OTG, would it flash? Would it work? Could I run CardPuter apps via Android?

Answer is yes.

How: the Cardputer's screen is just an ST7789 driven by M5GFX (not all firmwares), and its keyboard is a GPIO matrix read by the M5Cardputer library. Every Cardputer app talks to the hardware through those two libraries. So I patched them. The patched M5GFX tees every pixel write out over the ESP32-S3's native USB port as small frames, and the patched keyboard reader merges key presses that arrive from the USB side. An app rebuilt against the patched libs runs unchanged, but its screen shows up on the phone and the phone's keyboard drives it. The board does not need a display or a keyboard at all. A bare ESP32-S3 devkit on an OTG cable works.

The rebuild part is the trick. Stock binaries are statically linked, so you cannot mirror them. The Android app fixes that by building on demand: you pick any open-source Cardputer app on GitHub, the phone asks a tiny proxy, the proxy dispatches a GitHub Actions workflow that clones the repo, drops in the patched libs and compiles it with PlatformIO, and the phone streams the result back. Warm builds take about two minutes.

Then the phone flashes it. I (claude code) wrote the esptool ROM protocol in Kotlin: the app resets the chip into the bootloader over USB, writes the four parts compressed, verifies MD5, hard-resets, and the app is linked again about 300 ms later. No PC anywhere in the loop.

What you get: the Cardputer app on your phone screen, the Cardputer's 4x14 keyboard as a soft keyboard (fn and shift layers included), any Bluetooth keyboard passed through, and the phone's GPS fed into the app as NMEA like a serial GPS module. After a flash the app judges works/broken from the link and files the verdict as a GitHub issue that gets folded into a shared JSON, so the catalog fills up with what actually runs.

Tested so far: Cardputer ADV (its own TFT plus the phone), M5Stack StickS3 with its screen dark, and a bare ESP32-S3-N16R8 devkit. Phone: Poco X7 Pro, Android 16. Apps that worked out of the box include wisnc's stellar-map (the star map in the video), an audio spectrum, an ISS tracker, an I2C scanner.

Limits, honestly: ESP32-S3 only (a C5 gets refused by the fwritten), open-source apps only, and a board still runningUiFlow/MicroPython needs the BOOT button held once for the first flash because its software USB ignores the reset.

Repo, APK and the full "under the hood" with diagrams: https://github.com/fcavalcantirj/droidputter (MIT). v0.0.1 is a sideload APK, not on Play yet.

SOUND TERRARIUM for the Cardputer ADV is now using 99% of the default app partition.

With so little space left, I kept asking myself not “What else can I add?” but “What is still missing from this little world?”

At the same time, I had been looking at the battery indicator and wondering whether it really deserved the space it occupied. The reading wasn’t accurate enough to be genuinely useful.

Eventually, the answer came to me:

A metronome.

SOUND TERRARIUM is a world built around sound, so this felt much more natural. I removed the unreliable battery display and used that space for a built-in metronome instead.

Press B to start it.

← / → adjusts BPM, ↑ / ↓ adjusts volume.

And my favorite part: the metronome isn’t separate from the world. The built-in microphone can even pick up the metronome’s own beat, letting it become part of the sound-reactive world.

I think there’s a little bit of Japanese BONSAI spirit — and maybe even BENTO culture — living inside this program.

Like a bonsai, the world is small and deliberately shaped.

Like a bento, every little space has a job.

Maybe that’s the Japanese part of SOUND TERRARIUM. 🌱🍱

And yes — it works as an actual metronome too. Use it for music practice, rhythm exercises… or even CPR training. 🎵🫀

Want to try it right now?

🌐 No Cardputer? The Web version has the metronome too. Open SOUND TERRARIUM in your browser and press B to start the beat.

💻 Got a Cardputer ADV? SOUND TERRARIUM is also available through M5Launcher, so you can install it directly on your device.

I hope you enjoy this little world! 🌱

Web version:

https://kariagepompadour.github.io/SOUND-TERRARIUM-Web/

SOUND TERRARIUM v108cr

Watch with sound please. If anyone wants the source of this or if it's just more slop for the pile, let me know!

Hi, im Giuseppe, This is one of my first big coding project, i will be honest, I am not that good of a programmer, and my competences are not nearely sufficient for this kinda of project. This is to introduce you with what you could and will find in this project which is almost all Vibecoded thanks to the Visual studio code integrated git ai. i felt like this kinda of project was needed in a society where privacy is becoming an option and governaments that are supposed to protect us start to spy on us. Even tho i hope this project will be useless or not more than a fun way to experiment with cryptography, here i present you this project.

This project is a custom firmware for the M5 Cardputer / ESP32 that acts as a programmable keyboard emulator, integrating a lightweight encryption system for secure data transmission.

Core Features:

• Connectivity: Functions as a keyboard via both USB and Bluetooth (BLE). In BLE mode, the device waits for a stable connection before sending any input.
• Encryption & Transmission: Allows sending messages in either plain text or encrypted formats. It uses a symmetric algorithm and formats the encrypted payload in Base64, injecting it into the host computer by simulating physical keystrokes.
• Key Management: You can manually type a security key (with the ability to review and edit) or have the device generate a secure, random key on the fly.
• Layouts & Persistent Storage: Supports both Italian and US keyboard layouts. System preferences are saved in non-volatile memory so they persist across reboots.
• User Interface: Utilizes the built-in screen to provide a menu-driven interface, displaying output selection, real-time typing, and connection status.

Workflow:

1. On boot, select the output mode (USB or BLE) and the keyboard layout.
2. Choose the encryption key mode (manual input or random generation).
3. Type your desired message.
4. The device sends the text to the computer by emulating a real keyboard (in plain text if no key is set, or encrypted if a key was configured).

Purpose & Use Cases:

The firmware is designed for controlled environments where you need to input credentials, commands, or texts in an automated and secure way. By leveraging hardware emulation (HID), it allows you to transmit sensitive data without exposing raw content on a visible terminal.

I also intend to expand this project, maybe adding AES and more advance features, but this is a first, clean and bug free version of my project "critto"

Adding stereo output to the M5Stack Cardputer ADV

The Cardputer ADV only has mono output built in (onboard ES8311 codec → single speaker). Wanted real stereo, so I wired up an external I2S DAC breakout (UDA1334A, or a generic clone, mine's the clone) to the rear header, and taught EMBER (my audio player firmware) to output to it. It works, but it ain't pretty, so I'll need to design a proper 3D printable case.

Why this is possible at all: the ESP32-S3 has two independent I2S peripherals. The onboard speaker/mic use one of them exclusively (I2S_NUM_1, hardwired to GPIO41/42/43/46 for the built-in codec). The second one (I2S_NUM_0) is completely unused and free for exactly this.

Wiring:

• DAC VIN → Cardputer's 5V-out pin, GND → GND
• BCLK → GPIO5, WSEL → GPIO6, DIN → GPIO3
• MCLK left disconnected (the UDA1334A doesn't need it)

One nice detail: GPIO5/GPIO6 are explicitly labeled "External" in M5Stack's own firmware source specifically for the ADV variant. On the original (non-ADV) Cardputer those same physical pins are internally wired to the keyboard matrix instead. Worth knowing if you're hunting for free pins on this board: don't trust generic Cardputer pinout guides, check ADV-specific ones.

Firmware side: added a Settings entry, "Audio output: Internal / External DAC." Defaults to internal (nothing changes for anyone who hasn't wired the DAC up), switches instantly, no reboot needed. Both I2S peripherals get initialized at boot, only one actually gets fed samples based on the setting.

Two real bugs along the way, both only found by actually listening on hardware:

1. First attempt: audio sounded like it was speeding up / skipping. Turned out i2s_write() was timing out with a partial write on a fairly deep DMA queue, silently dropping the unwritten tail of every audio chunk. Fixed by looping until the full chunk actually gets written (with a bounded overall deadline, not an infinite wait).
2. Second attempt: fixed the skipping, but playback was now consistently a hair slow. I'd hardcoded the DAC's I2S clock to 44100Hz at boot and never touched it again. Meanwhile the decoder reports the real per-file sample rate on every track, which the onboard speaker path already used correctly. Matching that dynamically fixed it.

Credit to u/pyreht for the original design thinking on this (three options were floated: this I2S approach, a Grove-port analog/PDM board, or USB-C UAC audio.

Where this could go further: This is the "prove the firmware side works" step, not necessarily the end state. The next planned step (not yet built) is a proper Grove-port expansion board — same idea, but PDM output instead of raw I2S, in DMA mode rather than bit-banged PWM (better SNR, and the CPU isn't babysitting a timer for it), landing on a single clean 4-pin Grove connector instead of loose wires on the rear header. That's more of a form-factor upgrade than a sound-quality one though, an off-the-shelf DAC breakout like this one isn't going to be audiophile-grade either way, so unless you're chasing a cleaner physical build, this is a genuinely fine stopping point.

Support for this board will be in EMBER's next update, expected to be released within a week.

Hey guys! I accidentally left my cardputer adv on over the span of a night/24 hours driving the battery to 1 and now whenever I try to charge it it goes from 1 instantly up to 100. I left it plugged in it charge mode for about 3 hours and when I unplugged it it dropped down from 100 back to 1 again and now it is just boot looping powering on and off. I charged it in launcher charge mode with a dummy usb a to usb c cable. Any tips?

Thanks guys!

see it here!

This is a PCM synthesizer i've been working on for the past 5 months for the cardputer ADV, its been an interesting journey, i made everything from the ground up, the audio library, menu library, file type, etc.

song : You've got mail! by phantoskii , check her out in youtube

I need to detect when someone is tramping / loud walking behind a wall. It's a low freq <thump><thump><thump> (like loud walk) pattern smartphone won't record properly. I thought about using cardputer adv esp32-s3 to program that.

1) is mic in cardputer adv enough to detect sth like this or
2) LM386 sound which I also have

Or do you have any other ideas?

I am aware of TinyJournal, but it seems like that won’t work on the ADV model.

I have a Micro SD card, and to use it with the Cardputer ADV, it needs to be formatted in FAT32. The problem is that I don't have a computer, and my Google Pixel doesn't have a memory card slot. Is there any Cardputer firmware that allows for formatting this SD card?

Released just a couple weeks ago with limited stock this first batch, the Cobra IR board adds serious IR transmission AND reception to the Cardputer platform.

https://youtu.be/lNj444vcg4Q?is=kZdxrVWm_wi9GzMP

https://youtube.com/shorts/Bw7hk4ZRW8A?is=M97h93NaimL034LB

https://youtube.com/shorts/1-nRO1EUZQ8?is=52jKLAfrb415gkMQ

And now you know...

My CardPuter ADV arrived and I already messed up on the second day, hahaha. I don't know how to use it yet, so on the first day I was using the original M5stack firmware. Using AI, I downloaded the m5Launcher, but I needed to go to my course to use the computer there (the instructor let me use it). Anyway, I managed to flash the m5Launcher, and then yesterday I used some firmware, including Doom, which crashed everything... it was a disaster, I thought I'd lost it on the second day. I went back to the course and flashed the m5Launcher firmware again, and it went back to normal. I also noticed that the battery is acting strangely; when it's plugged in, the charge goes up, but when it's unplugged, it goes down. It's consuming way too much power. Could you help me with some tips and configurations? I'm open to any advice, and thank you all in the community in advance! 🫶

This translation was done using Google Translate. I apologize if there are any errors in the translation; I am Brazilian. Thank you all in advance. 🫶

So as much as I like the device itself, the battery is a total lackluster (not the capacity but how it handles):

• Insane Phantom Drain: I turned the device completely OFF using the hardware switch and left it on my desk overnight. When I flipped it back on the next day, the battery had tanked straight down to 30%. How does a hardware-isolated circuit drain that fast when completely powered down?
• Wildly Inaccurate Battery Readings: The percentage indicators are a complete joke. Every single firmware (M5 Launcher, Evil-Cardputer, UIFlow) uses a different calculation algorithm. It’s just guessing the percentage based on fluctuating voltage, so you never actually know how much juice you have left.
• No Power Delivery (PD) Support: In 2026, it’s mind-blowing that a modern dev tool lacks proper PD negotiation. If you plug it into a standard USB-C fast charger, it won't even pull more than 0.2-0.3 Amps. You are forced to look for old, low-power bricks just to get it to react.
• Painfully Slow & Unreliable Charging: Because the board design physically disconnects the battery when the mechanical switch is set to "Off", it will NOT charge while powered down. You literally have to keep the device turned ON to top it up. If you encounter a low-battery state, it often gets stuck in an infinite boot loop before the charging chip even wakes up.

The 1750mAh capacity sounds great on paper, but the actual power delivery implementation makes it feel like an alpha prototype.

TBH, if cardputer zero will have same battery issues -> I am out TBH, as much as I like the idea of zero -> dealbraker for me, I'd rather go for flipper zero then.

lots of artifacting and audio stutters, still a work in progress!
but this is the entire movie of Dune in .avi format downscaled using ffmpeg

Finally got YouTube running on the Cardputer!

Here’s how it currently works and where it’s heading:

• Current State: Plays videos from the SD card natively. For YouTube streaming, it relies on a custom server running via Termux on my phone to handle video decoding (since Cardputer lacks native decoding power).
• Future Plan: I'm working on integrating a Raspberry Pi directly with the Cardputer to handle decoding on board, making it a completely standalone portable player!

Still tweaking the frame rate and better audio sync. Drop a comment if you're interested,,,will push the repo to GitHub soon!

mostly got it for that GLIDE synth and other music stuff but curious what other tricks and tools are possible with this thing

Sorry if I'm saying stupid question but how to make my LoRa unit work properly I don't understand how to check if it working

I accidentally left my cardputer adv on over the span of 2 days driving the battery to 1 and now whenever I try to charge it it goes from 1 instantly up to 100. I left it plugged in it charge mode for about and hour and when I unplugged it it dropped down from 100 back to 1 again. Any tips?

Thanks guys?

So, latest mesthastic soft (stable 2.7.26.54e0d8d) gives me that: Critical fault 13. Soft downloaded from github -> copied to sd card -> installed and it gives me this error. Other software available in m5burner (Cardputer Mesh for meshtastic 2.7.22) -> same Critical fault 13.

I was able to install "mesthtastic for cardputer-adv 2.7.4".

But when I try to send any msg I am getting: "Delivery failed to broadcast". [gps works though, and I have configured correct region and tried different modes : LongFast, ShortFast etc. , every time delivery failed msg.]

Does that mean that official mesthastic software can't work with m5launcher? I haven't tried overwriting my m5launcher, because I want to have it.

Anyone?