Is VS300FL4 (VS500Z board, Lite Duplex panels) compatible with this project?

[cmac45]

Hi @MagnusPer and everyone,

I'm trying to add WiFi control to my Balboa VS300FL4 hot tub and after a lot of research and testing, I believe this project may be my best path forward. I'd really appreciate any guidance on compatibility.

My Hardware

Component	Details
Control Pack	Balboa VS300FL4 (Part Number 54626-03)
Circuit Board	VS300FLXR1B on the VS500Z platform (P/N 22972_E2, Copyright 2014)
Topside Panel	Lite Duplex type — VL401 or VL403 style, 4-button, connects via RJ45 8-pin into J2
Spa	AquaLife by Strong Spas
Configuration	1 pump (2-speed), ozonator, 12V light. No blower, no circ pump.
SSID on power-up	100, 59, 41

Why I think this project applies to my board

My VS300FL4 uses the VS500Z board platform, which is the same platform as the GS510SZ. The topside panels (VL401/VL403 "Lite Duplex") use a proprietary clock/data multiplexed protocol — NOT RS-485 at 115200 baud.

I originally went down the esp8266_spa / ccutrer RS-485 route but after testing discovered:

• ❌ No 12V power on the RJ45 pins (getting ~5V across multiple pairs instead)
• ❌ No RS-485 differential signal detected
• ❌ No continuity between RJ45 ground and chassis ground (isolated)
• ❌ The Lite Duplex panels don't use the same protocol as BP series (TP600/TP800) panels

This all points to the clock/data protocol that your GS510SZ project decodes.

What I have ready

• ✅ Raspberry Pi 5 running Home Assistant OS with Mosquitto MQTT broker configured
• ✅ ESP8266 (NodeMCU ESP-12E) — ready to reflash with different firmware
• ✅ RS-485 to TTL module (may not be needed if this is clock/data protocol)
• ✅ LM2596 buck converter set to 3.3V
• ✅ Multimeter and soldering iron
• ✅ Cut ethernet cable with RJ45 connector for tapping into J2

My Questions

1. Is the VS300FL4 / VS500Z board compatible with this project? The board platform and panel type seem to match, but I want to confirm before I start wiring.

2. Which RJ45 pins carry the clock, data, and button signals on the VS500Z board's J2 connector? I've been unable to find documentation on the 8-pin RJ45 pinout for this board. If you know the pinout or can point me to it, that would be incredibly helpful.

3. Do I need different hardware than an RS-485 module? Since this is a clock/data protocol rather than RS-485, I'm guessing I connect the ESP GPIO pins directly to the clock/data lines (with appropriate voltage level shifting if needed)?

4. Power supply from the RJ45 jack — I measured ~5V between several wire pairs on J2. Is 5V correct for the Lite Duplex topside power, and which pins are +V and GND?

Photos of my board

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I'm committed to getting this working and happy to do any testing, tracing, or debugging that would help. If this project isn't the right fit, I'd appreciate any pointers in the right direction.

Thanks for building this project! 🙏

[sktyrhrtout]

I was able to get it to work on my VS500Z pack. I ended up ordering the PCBs from JLPCB. I had to source a couple parts that weren't available but I have it installed and working. I also had to tweak the code a bit to get it to work for me. I will try and get my version uploaded here.

If you'd like, I can send you a board with a WEMOS D1 Mini. The board would be $35 and the D1mini would be an additional $5 so $40 + shipping. It will come with headers but you'll do the soldering.

[cmac45]

Thanks for that offer, I may take you up on that. I am going to do some testing with my ESP microcontroller first and see if I get stuck then may get one of the boards from you.

…

On Tue, Apr 14, 2026 at 8:42 PM sktyrhrtout ***@***.***> wrote: *sktyrhrtout* left a comment (MagnusPer/Balboa-GS510SZ#37) <#37 (comment)> I was able to get it to work on my VS500Z pack. I ended up ordering the PCBs from JLPCB. I had to source a couple parts that weren't available but I have it installed and working. I also had to tweak the code a bit to get it to work for me. I will try and get my version uploaded here. If you'd like, I can send you a board with a WEMOS D1 Mini. The board would be $35 and the D1mini would be an additional $5 so $40 + shipping. It will come with headers but you'll do the soldering. — Reply to this email directly, view it on GitHub <#37 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADB2RN6OROEH5U2J4KEYH634V3ZJRAVCNFSM6AAAAACXYIGDE2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHM2DENBYG42DGNJSGA> . You are receiving this because you authored the thread.