[Feature Request] OLED Display Support for Hardware Status & Network Telemetry (SSD1306/SH1106 over I2C)

[zangaby]

Hello,

Would it be possible to add support for small external OLED displays (such as 0.96" or 1.3" SSD1306/SH1106 via I2C) to display real-time physical device status, IP addresses, video input resolution, and system health metrics?

When deploying ESP-KVM as a headless appliance in a server rack, lab, or home network:

• Finding the dynamically assigned IP address (Ethernet or WiFi/Tailscale) requires checking router DHCP tables or mDNS discovery.
• Identifying whether the target machine is outputting a valid HDMI signal (or if EDID negotiation failed) requires opening the Web Console.
• Confirming device status during network troubleshooting or AP fallback mode requires guesswork or serial log inspection.

Proposed Solution
Integrate an optional display task into the ESP-KVM firmware to drive an I2C OLED display (e.g., 128x64 SSD1306/SH1106).

The screen would cycle through or show key device telemetry at a glance without impacting video encoding (MJPEG/H.264) or USB HID performance.

1. Network Status (Main Screen):

   • Active IP address (ETH0 / WiFi / Tailscale IP)
   • Connection state (Connected, AP Rescue Mode, Disconnected)
   • Web Console URL (e.g., https://espkvm.local or raw IP)

2. Video Capture & Stream Telemetry:

   • HDMI Input Status: Resolution & Refresh Rate (e.g., 1080p@30 or No Signal)
   • Active Stream Status: Encoding format (MJPEG/H.264) & Connected client count

3. System Health & Status:

   • ESP32-P4 Core Temperature (°C)
   • Memory/Heap Usage
   • System Uptime

4. Boot & Rescue Mode:

   • Show initial boot sequence / network connection status.
   • If in Rescue AP Mode, display the AP SSID, password hint, and captive portal IP.

Thanks !

[dexif]

Hi! Yes, that's exactly what I'm doing now. ;)

[dexif]

SSD1306/SH1106

[dexif]

Also GC9A01 https://www.youtube.com/watch?v=-snDjOOjbSA

[dexif]

Already released https://github.com/espkvm/espkvm/releases/tag/v.0.21.0

[DaveDavenport]

Very neat! I got tons of these displays (gca9a01) lying around, so gonna give it a try.

Its starting to get more and more tempting to make a all in one PCB.

[zangaby]

@dexif - Thank you !

[DaveDavenport]

Also works with the cheap ali 1.5" version (gc9a01a)

Following pins are safe on nano-p4:

[dexif]

Now, to connect to a WiFi AP, a QR code is displayed on the round display. The OLED display is too small for a QR code, so it displays the SSID and password if set.

[zangaby]

Would it be too much trouble to add support to the SSD1315? I just tried connecting one (0.96-inch 128 x 64 pixel) but unfortunately nothing came up on the screen.

[dexif]

what does Settings -> Display say, and what is in the log right after boot (/api/v1/system/log)?
"no I2C OLED detected (0x3C/0x3D)" - the panel is not answering on the bus at all, and no driver change would help. The mono OLEDs hang off the capture chip's I2C bus, so it is those two pins, and the module has to be at 0x3C or 0x3D.
If the log says a panel attached and the glass stays dark - then it is the init sequence, and that I can do something about.

[dexif]

for a 0.96 128x64 module the right entry is the default one, SSD1306 128x64. The panel size cannot be detected - one controller drives every size and reports none of it - so a wrong pick shows nothing useful, or nothing at all.

[dexif]

The SSD1315 is close enough to the SSD1306 that the sequence I send ought to work unchanged.

[zangaby]

Device Log Output

--- boot: v.0.41.1 ---
W (1764) espkvm: boot: after power on; running ota_0 (confirmed)
I (1774) kvm_cfg: 88 settings loaded
I (1774) temperature_sensor: Range [20°C ~ 100°C], error < 2°C
W (1804) auth: hold the button now (2 s) to clear the password and restore the network
I (9804) espkvm: boot: storage
I (9804) storage: rescue partition: 4096 KB, empty
E (9844) sdmmc_common: sdmmc_init_ocr: send_op_cond (1) returned 0x107
E (9844) vfs_fat_sdmmc: sdmmc_card_init failed (0x107).
E (9844) vfs_fat_sdmmc: esp_vfs_fat_sdmmc_sdcard_init failed (0x107).
I (9854) storage: mount attempt 1/10 failed: ESP_ERR_TIMEOUT
W (9874) gpio: conflict found for GPIO[42]
E (9944) sdmmc_common: sdmmc_init_ocr: send_op_cond (1) returned 0x107
E (9944) vfs_fat_sdmmc: sdmmc_card_init failed (0x107).
E (9944) vfs_fat_sdmmc: esp_vfs_fat_sdmmc_sdcard_init failed (0x107).
I (9954) storage: mount attempt 3/10 failed: ESP_ERR_TIMEOUT
W (9974) gpio: conflict found for GPIO[42]
...
I (10304) storage: no card in the slot
I (10314) espkvm: boot: ethernet
I (10844) esp_eth.netif.netif_glue: e8:f6:0a:e7:22:a0
I (10844) esp_eth.netif.netif_glue: ethernet attached to netif
I (12944) net: Ethernet link up (100 Mbps)
I (12944) mdns_mem: mDNS task will be created from internal RAM
I (12944) net: mDNS: [https://espkvm.local/](https://espkvm.local/)
I (12944) espkvm: boot: web server
I (13274) auth: PBKDF2 self-test passed (4096 iterations in 325 ms)
I (13274) tls: certificate for espkvm.local loaded
I (13274) esp_https_server: Starting server
I (13284) esp_https_server: Server listening on port 443
I (13284) web: serving on https://, port 80 redirects
I (13284) espkvm: boot: usb
I (13284) usb_hid: USB functions: HID only
W (13294) tusb_desc: No Device descriptor provided, using default.
W (13294) tusb_desc: No Qualifier descriptor provided, using default.
I (13304) tusb_desc: 
┌─────────────────────────────────┐
│  USB Device Descriptor SummI (13474) TinyUSB: TinyUSB Driver installed on port 1
I (13574) usb_hid: re-attached to the target so it enumerates this boot
I (13574) jiggler: ready (jiggle_s=0)
I (13574) espkvm: boot: capture
I (13614) storage: media ejected
W (13624) kvm_caps: audio probed but not compiled in
I (13624) mqtt: disabled
I (13624) kvm_caps: video   unavailable: not probed yet
I (13624) kvm_caps: mjpeg   unavailable: not probed yet
I (13624) kvm_caps: h264    unavailable: not probed yet
I (13634) kvm_caps: hid     active
I (13634) kvm_caps: msc     available, switched off in settings
I (13644) kvm_caps: atx     unavailable: set the power and reset button GPIOs (Settings -> Power)
I (13654) kvm_caps: wol     active
I (13654) kvm_caps: audio   unavailable: not built into this firmware
I (13654) kvm_caps: https   active
I (13664) kvm_caps: ota     active
I (13674) kvm_caps: net_static active
I (13674) kvm_caps: wireguard active
I (13674) kvm_caps: tailscale active
I (13674) kvm_caps: wifi    unavailable: not built into this firmware
I (13684) kvm_caps: display unavailable: not probed yet
I (13684) espkvm: ready
I (13684) video: H.264 available: 640x480 costs PPA 11301 us + encode 4704 us; predicted ceiling 9 fps at 1080p, 20 fps at 720p
I (13704) main_task: Returned from app_main()
I (13914) video: TC358743 RESETN released on GPIO 23
I (13944) esp_netif_handlers: eth ip: 192.168.178.43, mask: 255.255.255.0, gw: 192.168.178.1
I (13944) net: Got IP: 192.168.178.43
I (13944) net: Open [https://192.168.178.43/](https://192.168.178.43/) or [https://espkvm.local/](https://espkvm.local/)
I (13964) tc358743: EDID profile: full mode list
I (14004) tc358743: CHIPID 0x0000
I (14024) tc358743: SYS_STATUS=0x00 (TMDS=0 HDMI=0 SYNC=0 DDC5V=0)
I (14174) video: CSI rgb888 24bpp ring 2x6220800 bytes for up to 1920x1080 (align 64)
I (14314) net6: IPv6 link-local address FE80::EAF6:AFF:FEE7:22A0
I (14374) tc358743: SYS_STATUS=0x01 (TMDS=0 HDMI=0 SYNC=0 DDC5V=1)
I (18374) esp_https_server: performing session handshake
W (19374) video: HDMI lock wait 5000 ms - starting CSI anyway
W (19374) video: no HDMI signal yet - starting at 1920x1080
I (19374) video: capture running at 1920x1080
I (19464) video: codec: mjpeg
I (25464) esp_https_server: performing session handshake
I (47304) esp_https_server: performing session handshake
W (47314) web: websocket refused: no session
W (47314) httpd_uri: httpd_uri: ws_pre_handshake_cb failed
I (47314) esp_https_server: performing session handshake
I (47544) esp_https_server: performing session handshake
W (47764) web: websocket refused: no session
W (47764) httpd_uri: httpd_uri: ws_pre_handshake_cb failed
I (47854) esp_https_server: performing session handshake
W (47864) web: websocket refused: no session
W (47864) httpd_uri: httpd_uri: ws_pre_handshake_cb failed
I (48884) esp_https_server: performing session handshake
W (48894) web: websocket refused: no session
W (48894) httpd_uri: httpd_uri: ws_pre_handshake_cb failed
I (51064) esp_https_server: performing session handshake
W (51334) web: websocket refused: no session
W (51334) httpd_uri: httpd_uri: ws_pre_handshake_cb failed
I (52404) auth: logged in as 'admin'
I (52534) esp_https_server: performing session handshake
I (52544) esp_https_server: performing session handshake
I (52774) esp_https_server: performing session handshake
I (53004) esp_https_server: performing session handshake
I (55344) esp_https_server: performing session handshake

I tried to check with a I2C scanner on a different board and

`[23:25:20.854][C][i2c.idf:113]: Results from bus scan:
[23:25:20.860][C][i2c.idf:119]: Found device at address 0x3C` 

[dexif]

Your log never mentions the display at all - not "no I2C OLED detected", not a panel attaching, nothing. That is what it looks like when the display is switched off: the task never probes the bus, and the capability line stays at the not probed yet you can see at 13684 ms.

So: Settings -> Display -> Status display, on. It is off by default. Then reboot or wait a couple of seconds and read the log again - it will now say either no I2C OLED detected (0x3C/0x3D) or which panel attached, and that tells us which problem we actually have.

[zangaby]

Thanks, I just tried another display module and this time it worked. Maybe I somehow damaged the previous one.