Feature Request: Combo Extension (DC / AC Power Control + Serial Console)

[jidckii]

Feature Request: Combo Extension (DC Power Control + AC Power Control + Serial Console)

Problem Description

I'm managing a compact appliance (a small network security device similar to a mini PC/nettop) that has:

• DC power input (12V 3A barrel jack) — no ATX headers available
• Serial console port (RJ-45) for out-of-band management

Currently, JetKVM offers separate extensions for DC Power Control and Serial Console, but only one can be connected at a time via the single RJ-12 extension port.

My Current Workaround

I ended up buying an old ATEN KN1000A specifically because it has both:

• Built-in power relay (can cut/restore AC power to the device)
• Serial console support
• KVM functionality

This is a legacy device from ~2010s, bulky, expensive on secondary market, and overkill for my needs. But it was the only "all-in-one" solution I could find.

📷 My current setup (click to expand)

---

---

Use Case

For compact appliances, mini PCs, NAS units, and embedded systems:

1. Power Control is essential — these devices often hang hard (kernel panic, firmware issues) and the only recovery option is a full power cycle. There's no reset button accessible, no ATX headers. Depending on device type, you need either:

   • DC power switching (for devices with external "brick" PSU)
   • AC power switching (for devices with internal PSU or to control the brick itself)

2. Serial Console is critical for:

   • Bootloader access (GRUB, U-Boot)
   • Kernel boot messages
   • Emergency recovery when network is down
   • Configuration of devices that don't have HDMI output

3. All three are needed simultaneously — when a device hangs, I need to:

   • Power cycle it via relay (DC or AC)
   • Watch the boot process via serial console
   • Intervene if needed (select boot option, enter recovery mode)

Proposed Solutions

Option A: Universal Combo Extension Board (DC + AC + Serial)

The ultimate solution — a single extension that combines:

• DC Power Control relay (12-20V, 5.5×2.5mm jack) — for external PSU devices
• AC Power Control relay with IEC C14 inlet / C13 outlet — for internal PSU devices
• RS-232 serial interface (DB9 or RJ-45)
• Power monitoring (voltage, current)

Why IEC C14/C13 for AC:

• Universal standard — works in any country (US, EU, UK, AU, etc.) with just a cable swap
• No regional SKUs needed — one product fits all markets
• Already familiar — every server, desktop PSU, monitor uses this connector
• Cheap adapters everywhere — country-specific plug to C13 cables cost $2-5 globally

This would essentially be a "smart PDU + serial console" in JetKVM extension form factor — similar to what ATEN KN1000A has built-in, but as a compact modular add-on.

Option B: Separate AC Power Extension

If combo is too complex, at least offer a standalone AC Power Relay Extension with C14/C13:

• Acts as a managed "smart socket" controlled via JetKVM web UI
• No WiFi/Zigbee dependency (unlike consumer smart plugs) — wired control only
• Bistable/latching relay with configurable state after power loss

Option C: Extension Daisy-Chaining

Add an RJ-12 passthrough port on extensions, allowing:

JetKVM → DC Power Extension → Serial Extension → Device

Option D: Second Extension Port

Future JetKVM hardware revision with two RJ-12 ports.

Why This Matters

Looking at the market:

• PiKVM V3/V4 has both ATX control AND serial console built-in
• ATEN KN1000A (legacy) has AC power relay + serial + KVM
• Smart PDUs exist but are expensive ($100+) and require separate management
• Consumer smart plugs all use WiFi/Zigbee — not acceptable for server rooms/racks (wireless restrictions, reliability concerns)
• JetKVM is modern, affordable, has great software — but limited to one extension

I was surprised to find almost no modern wired USB-controlled power relay on the market:

• Smart plugs are wireless-only
• USB relays lack bistable contacts with state memory
• Proper managed PDUs start at $200+ and are overkill for single-device management

JetKVM is perfectly positioned to fill this gap.

Target Users

Homelabbers and small business IT managing:

• Mini PCs (Intel NUC, Minisforum, Beelink)
• Network appliances (pfSense boxes, routers, firewalls)
• Embedded systems with external PSU
• NAS devices
• Single-board computers
• Any device with "brick" power supply or standard IEC inlet

...the combination of power control (DC or AC) + serial console is a very common requirement.