ESP32-C3 round display firmware

ChargeScreen

A small standalone dashboard for Victron Bluetooth data, solar status, and battery experiments. Built for the JCZN ESP32-2424S012 round display.

Download latest Setup guide
ChargeScreen circular battery dashboard showing a segmented charge arc and four battery values
Current build: beta 4.13 Use the latest build unless you are testing a specific older version.

Getting started

How to use ChargeScreen

1

Flash the firmware

Install the latest firmware for the JCZN ESP32-2424S012 board. After flashing, keep the device powered while it restarts.

2

Open settings

Tap the cog on the bottom of the round display, then tap WiFi. Join the temporary hotspot named ChargeScreen.

3

Visit the setup page

Open http://192.168.4.1/ on your phone. The page is also set up as a captive portal, so many phones will offer to open it automatically.

4

Save your settings

Paste Victron Instant Readout keys, select sources, set screen rotation, dimming, screen timeout, demo values, and solar panel watts.

Victron setup

Getting the encryption codes

ChargeScreen reads Victron Instant Readout Bluetooth adverts. Those adverts are encrypted, so each Victron device needs its own Instant Readout encryption data.

  1. Open the VictronConnect app near your SmartShunt, BMV, SmartSolar, or other supported Victron Smart device.
  2. Connect to the Victron device over Bluetooth.
  3. Open settings, tap the three dots, then open Product info.
  4. Enable Instant Readout if it is not already enabled.
  5. Find Instant Readout details or encryption data and choose Show.
  6. Copy the MAC address and encryption key into the ChargeScreen setup page.

Victron documents Instant Readout in the VictronConnect manual. The exact wording can vary slightly between app versions and device types.

VictronConnect Instant Readout manual

Compatibility testing

Using BLE capture

BLE capture records nearby Bluetooth Low Energy adverts for 5 minutes. It is useful when adding support for batteries or accessories that do not decode correctly yet.

  1. Put ChargeScreen close to the battery or Bluetooth device you want to identify.
  2. Open the ChargeScreen WiFi setup page.
  3. Press Start 5 Minute BLE Capture.
  4. Wait for the capture to finish, or stop it early from the screen or webpage.
  5. Download the CSV file when it is ready.
  6. Email the CSV and any battery app Bluetooth encryption codes to chargescreen.ricopicouk@gmail.com.

Privacy note: the CSV may include packets from nearby watches, phones, TVs, sensors, and batteries. Most of it is encrypted or only useful to the original device, but it will still appear in the file. Battery encryption codes are only used to decode the battery packets in the capture.

Firmware

Downloads and changes

Latest

beta 4.13

WiFi idle timeout fix, beta 4.12 solar wattage changes, and the latest web settings flow.

Download beta 4.13
Build Status Notes Download
beta 4.13 Latest Fixes WiFi idle timeout being kept alive by webpage polling, and refreshes the UI when WiFi turns off. Firmware

A quick warning

Firmware updates

During a web firmware update, keep the device powered and wait for it to restart. Removing power during an update can leave the device needing a USB reflash.