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New version of the EMS screw terminal cable

Since the end of April 2024 I have a new version of the EMS screw terminal cable.

It’s still a 100cm cable with two stranded copper cores of 2×0,5mm2 and the wire ends terminated with a wire ferrule, but now the cable is black and a bit thinner and more flexible than the previous grey cable.

You can find the cable here or you can include it as an option on the Gateway and Interface board product pages.

Below on the left the ‘old’ version of the cable and on the right the new version.

Some more product images:

You use this cable to connect the orange or green screw connector of the Gateway to the EMS screw terminal inside the boiler or heat pump.

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Gateway model E32 V2 now available

It took a bit longer than expected but the first batches of the new Gateway model E32 V2 with WiFi and LAN are now available.

It has all the awesome features of the S3 Gateway with the same EMS-ESP32 firmware but aside from WiFi it has an additional RJ45 Ethernet port for wired networking.
Because the ESP32-S3 chip of the S3 Gateway does not support hardware Ethernet we used a big ESP32 module instead but with a beefy 8MB PSRAM and 16 MB Flash. This solves all the little memory issues of the previous E32 some users might be experiencing with the latest 3.6.x firmware when used with larger EMS systems.

Although the E32 V2 hardware has 8MB of PSRAM, currently the EMS-ESP32 firmware only supports 4MB PSRAM on the ESP32. 4MB is more than enough for now, but if needed this can be increased to 8MB in the future.
Furthermore EMS-ESP32 currently only needs 4MB of Flash storage, so with 16MB of Flash storage in the E32 V2 there is lots of room for more features.

Because the circuit board did not fit anymore into the grey enclosure of the E32 V1.0/V1.5 and the S3 a new enclosure was created. It also has mounting holes on the back. Furthermore it is UL 94 V level fire retardant.

The E32 V2 went through several rounds of prototyping and is of course CE certified and manufactured according to the RoHS directive.
The LAN port provides a very stable interface. POE is not included though, non-isolated 48V is not a good match with the 16V EMS bus.

Currently there may be limited availability of this model, from March onward continuous stock is expected.

You can find it in the webshop HERE.

If you don’t need LAN the cheaper WiFi-only S3 and S3-LR are still a great choice as well.

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Improved wall mount bracket

The wall mount bracket for the S3, S3-LR, S32, E32 and older models is 3D printed.

We are now printing the brackets on a Bambu Lab X1 Carbon printer. The quality has been improved dramatically.
The left image shows the ‘old’ bracket on the left versus the ‘new’ bracket on the right. both are printed with the same filament. You can now hardly see it’s 3D printed.

EMS Gateway new bracket
EMS Gateway bracket comparison
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New Gateway models S3 and S3-LR available

As time progresses so does the EMS-ESP firmware. We were now at a point were EMS-ESP would benefit from some more RAM memory.

That’s why BBQKees Electronics is introducing the new EMS Gateway S3 models. One with the default on-chip antenna and an identical Gateway model with an external high gain antenna for those area’s with low WiFi reception. These are the replacement for the very popular S32 Gateway.

S3-LR front
S3-LR back

Hardware changes

The S3 models looks and feel identical to the EMS Gateway S32 V2.0 they are replacing but they now come with an ESP32-S3 module with 16MB Flash and a hefty 8MB PSRAM (in addition to the on-chip 512KB RAM), which makes it more suitable for large EMS systems with a heat pump or multiple zones/heating circuits.

The new hardware continues using the existing third-gen BBQKees EMS detecting and sending circuitry design as in the S32 Gateway and the EMS Interface board V3’s, which has proven extremely reliable and robust over the years for all EMS types across all Bosch brands.

Aside from the more powerful chip, this model now also features an external USB-C connector for manual firmware updates (if ever needed). The USB-C connection makes use of the internal USB OTG controller of the ES32-S3 so we don’t need the CH340 chip and driver anymore.

What has remained unchanged are the positions and pinout of the external connectors so the S3 is a direct replacement for S32 setups. Only the LED lightguide was changed a bit.

The power options via the service jack or 12V DC power supply also remained the same.


The S3 models will be loaded with firmware EMS-ESP32 v3.6. This is exactly the same firmware with the exact same features as for the S32, just built for the different chip architecture of the S3.
The 3.6 firmware contains a number of new features over 3.5.1, most notably further memory optimizations.

Upgrade discount

If you already own an S32 Gateway it’s probably not really worthwhile to upgrade to the new S3, but if you want too or if you still have an old ESP8266 Gateway like the Premium II you can get a 15% discount on a new S3 Gateway of your choosing. Just use the contact form to contact me with your previous order ID and I’ll give you a discount code.

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E32 back soon

Currently the E32 is sold out. We are still waiting on a shipment of boards before we can assemble new products.

The E32 will probably be back in stock before the end of October.

You can fill in your email address on the product page to be notified the moment stock is added.