Advice on using mmWave board with Node-RED

Hardware
1

Folks, sorry for dragging you into this.

Human detector project.
mmWave board:

Scrolling down there is a PIGGY BACK board that give me/you BT for connection.

I've never done any work with BT.
So writing the code on that end is one thing.

But putting that as DONE, HOW do I connect it from a RasPi 3B+ (Buster) in Node-Red?
NR Version 3.x

I thought BT was more for Audio than data......

2

Short answer use a module supported by Tasmota, and send data over MQTT.

e.g.

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3

Thanks.

I also just found out the Arduino board may be 3.3v which will make it a lot easier.

P.S.
MQTT is the way I was wanting to go, so that is good to hear.

4

Just checking.

The link from @smcgann99.... That's just the software, for that device.

I'll still need to have a network connection. (WiFi, BT or Ethernet)

5

Tasmota is firmware that runs on an ESP.

The ESP can connect via Wi-Fi and communicate using MQTT.

The sensor then talks to the ESP via a serial connection.

6

Ok, but the board I posted in post 1, it is ONLY the sensor.

There isn't any WiFi or BT.
So that would need a second board connected to it that has the network part.

If you scroll down on that link there is a BT board that can piggyback onto it.

So I am not understanding where you would install it.
On that board or on the BT board?

Sorry. Brain really isn't working these days.

7

I am suggesting NOT using the BT board but an ESP.

This video covers the idea well -

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8

Ok, so I get an ESP board and flash it with the Tasmota software.

Connect the mmWave sensor to the board, using defined pins.
Ok, I maybe can modify the config to use other pins. (But at this point that's just confusing the workings)

Then I set the stuff like the WAP, password and it connects to my WAP.

Then I can configure the Tasmota side of things.

All I need to do is make sure the ESP board and the mmWave sensor talk the same voltage. (3.3 or 5) and all should be good.

Am I starting to get a better understanding now?

(Again: thanks.)

9

Yes, you can use the Arduino IDE to do things yourself if you prefer. Or check out pre-canned firmware such as Tasmota as mentioned or something like ESPHome if you prefer.

I don't think I'd get that specific module though as it looks like it is specifically designed for the XIAO system. If not using that, you would probably need to deal with the low level protocol yourself.

HLK-LD2450 and the DFRobot SEN0395 (also known as the Leapmmw HS2xx3A series) both appear to be supported by ESPHome. And there are several how-to articles available.

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10

Yeah, it is a bit of a mine field on which sensor to use, and all that stuff......

I won't close this thread just now as I may have more questions.

(Sorry folks.) :wink:

Oh, sorry....

You said

use the arduino IDE

But that was just to flash TASMOTA onto the board.
Ok, I'd have to define which PINS are used to talk to the sensor.
I can handle that.

But then it is all done at the TASMOTA level - yes?
(That is: setting up the WAP, MQTT and stuff.)

Then it spits out MQTT messages as needed, and I just get the messages here and write a flow to act on the received messages.....

Or is there another elephant hiding somewhere?

11

No, it is an alternative if you want to have the "joy" of programming everything yourself :rofl:

If using one of the supported boards (not the one you originally listed), the pins are likely pre-defined for you.

As in this example for ESPHome:

ESP32 LD2450
5V <-> VCC
GND <-> GND
GPIO22 <-> RX
GPIO21 <-> TX

Which makes life a lot easier.

Then yes, the firmware should take care of the rest.

The difference between Tasmota and ESPHome is that you get a lot more control with ESPHome and you typically also end up with a smaller firmware which can help with stability on ESP boards, especially the cheaper ones. Tasmota, however, is more plug-and-play. I had stability issues with Tasmota in the past but that may well have been dealt with now.

The other advantage of ESPHome (which I use with HA by the way as many people do), is that you can split your config up into small YAML modules and so reuse them in other ESP projects. That is the biggest benefit for me, along with rock-solid stability, I have many different ESP boards (both ESP32 and ESP8266) but often re-use the same sensors/controllers and, of course, have the same Wi-Fi and other standard config. You can even easily dip into custom C++ if you need something out-of-the-ordinary. But it does take a bit more to do the initial dev setup.

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12

When you say supported board are you meaning the SENSOR or the ESP?

Sorry..... I really am not running at a good efficiency. :frowning:

Just checking.

13

The sensor board.

AFAIK, all ESP boards are supported by both Tasmota and ESPHome. ESPHome also supports BK72xx, RP2040, and RTL87xx microprocessor boards in addition to ESP32 and ESP8266,

Not sure how many sensor and controller boards are supported by Tasmota (looks like ~81), 574 are currently in the ESPHome device database.

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14

Thanks. My mistake.

But glad it was resolved now and not later. :wink:

I picked that one only as a NOMINAL one. Not knowing it had it's own set of problems.
(Shame on me for doing that)

Ok. Another step in the right direction now. :wink:

15

Not wanting to reignite the Tasmota V ESPHome debate - (well maybe a bit :wink: )

But at first glance there seems to be at least 174 distinct sensor drivers (many drivers support multiple variants) and 2831 supported ESP devices.
:grimacing:

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