temperature sensors – BBQKees.com

Temperature sensor

The first sensor is ‘gateway_temperature’ and is a SMD type DS18B20U temperature sensor that is mounted directly on the circuit board. The DS18B20 sensor is connected to GPIO14, which is the same pin used for connecting external DS18B20 sensors via the JST connector.
The sensor is positioned in the center of the board, away from hot components. This sensor measures the internal temperature of the Gateway. So it is not the internal temperature of the ESP32 chip itself, but the temperature inside the enclosure.
If you for instance mount the Gateway inside or on top of the boiler where it may get warm or hot (not recommended), you can keep an eye on the temperature. Or set an temperature alarm via the scheduler.

Voltage sensors

There are two voltage monitors on the circuit board.
The first one is ‘core_voltage’ which monitors the 3,3V output of the internal voltage regulator of the circuit board. This voltage is used to power the entire board. This voltage monitor is connected to GPIO39.

The second one is called ‘supply_voltage’ which connects to GPIO36. This monitors the external supply voltage of the Gateway. This can be coming from either the USB-C port (5V DC), the EMS service jack (8,5V or 12VDC) or the external DC input (12V DC).
If multiple power inputs are used at the same time, this monitor will show the highest voltage.

Blue LED

In the Analog Sensors section you can also find the entity ‘led’. This is not a sensor but it is a blue LED connected to GPIO2.
This is the LED that was mounted on all older E32 V2 circuit boards, and it is still mounted on the latest V2.2 circuit boards, even while there is also a RGB LED next to it.
The blue LED was maintained for backwards compatibility reasons. If you f.i. load firmware 3.7.2 or older, there is no support for the E32 V2.2 board profile, and the RGB LED won’t work.
But in normal conditions the blue LED is not used when the RGB LED is available. However, you can still turn it on or off via this sensor entity.

This guide will show you how to easily add some DS18B20 temperature sensors to your BBQKees EMS Gateway.
No soldering skills necessary.

You can add DS18B20 sensors to all BBQKees Gateways ever made by using the small 3-wire JST cable that is supplied with each Gateway order.

The easiest to use are waterproof DS18B20 sensors with a cable. These are cheap and convenient to use.
We do not sell these sensors, they are available at many places online.

You can add a number of these sensors in parallel to a Gateway. The specific number varies depending on the length of the cable and the type of DS18B20 sensor used. But in general 10 sensors is usually not a problem.

Make sure the sensors are all of the same DS18B20 sub-type and do not mix parasitic mode with normal mode wiring.

Prerequisites and parts

BBQKees EMS Gateway
3-wire JST ZH cable
DS18B20 waterproof sensors with cable
3 Wago 221 splicing connector with levers or f.i. a ‘lusterklemme’
Wire stripper

Step 1: Strip the wires on the JST cable

You need to strip the wires on the JST cable by about 10mm. If the wire ends are soldered, it’s better to cut them off at the point of the wire insulation before stripping. This will make stripping the wires easier.

Step 2: Strip the wires on the DS18B20 sensors

Strip them 10mm, or at least the same length as you stripped the JST cable.

Step 3: Tie the wire ends together

Tie the wire ends together. Tie each color separately. So all yellow wires together, all black wires together and all red wires together.
If there are too many cables, you can also do 2 or 3 cables each time.

Step 4: Put each wire color in a separate Wago clamp

This step is where you could make the most errors so be careful here.

You need to insert each cable bundle of it’s own color into a separate Wago clamp.
DO NOT put any other wire color in the same clamp as this will cause shortcuts.

End result DS18B20 sensors in Wago clamps

Step 5: Insert the JST plug into the EMS Gateway

Insert the JST plug into the JST connector in the Gateway. You need to keep the flat part of the plug at the top. Make sure it is fully inserted. See the image below for the correct orientation.

It’s best to turn off the Gateway before doing this. If the Gateway does not boot afterwards, you made a shortcut in the wiring.

Step 6: Check the EMS-ESP web interface and rename the sensors

If everything went correct, you will see the sensors appearing in the Sensors tab in the web interface.

Each DS18B20 sensor has it’s own unique address identifier. These identifiers are displayed.
You can click on one to rename it.
After you rename a sensor, it is also renamed in MQTT and Home Assistant etc.

If you added a bunch of sensors at the same time, it can be hard to distinguish them.
You can heat each sensor separately with f.i. a hair dryer or heat gun and see which one gets hotter.

And that’s it!

Tag: temperature sensors

Additional sensors on the EMS Gateway E32 V2.2 board