Howdy Arno and thanks for providing the links...I did take a peek at those already!

I'll take a look at the DS18B20 but I already purchased the LM34s (Fahrenheit version). I think the LM34 has a bit better accuracy yet DS18B20 is the less "painful" alternative!

I plan to:

1. look into the whole atten as that controls the voltage range to the ADC
2. look into an active low pass filter using a single supply Op-Amp
3. look into adding a small gain from the Op-Amp to get the voltage from the LM34 into an acceptable range for the ADC

Will share my findings along with any schematics I come up with.

Thanks-Brian

Hi all,

Some insights to share! Well the Active Low Pass filter did help to a small degree. With that said I decided to connect my Oscilloscope to the input of the ADC0 using GP35 and I was surprised by the amount of noise!

Input of ADC0 on GP35:
There was over 200mV of noise that varied in frequency of anywhere from 18 to 78MHz!

Measuring "ground" (just as a reference)
There was less then 100mV of noise that was around 60Hz which would be expected here in North America as our AC Line Frequency is 60Hz.

I did order some other one-wire temperature sensors including the DS18B20 and have another temperature sensor with a +_ 0.25 accuracy just to experiment with.

Again I will keep this post updated.

Thanks-Brian

@arno

Thanks Arno for the push in the right direction. I was able to get this to work on my Core 2 EXCEPT using G21 or G22.

I will write up a tutorial on try to find a way to post/share.

Thanks again Arno!

@timtimw
That is awesome that you were able to get I2C to work with the ADC1115. I would be very interested in your ADC project at many of us discovered the built-in ADC has a few challenges. Again as Arno added could you please post /share your code? I am trying to use DS18B20 with UIFlow but am having some difficulties.

Thanks Brian

@felmue

Awesome Felix!

Thanks for responding and clearning this up! Your response reminded me that I made the assumption that all Core 2 configurations are using the M5GO Bottom2 (which sorry to ceerietke as that may of confused you) which is not the case.

With that said you could remove the base and have direct access the GPIO pins directly inside the CORE 2.

@cerietke

I totally understand about the soldering. The quality of my soldering skills has diminished drastically along with my vision 😉

Ok, was really hoping someone with more experience with the Core 2 and Grove interface would step in here as I am a newbie yet here I go.

I don't believe the Ports can be used as standard GPIO. The Ports are used as IC2 Ports for serial based communication. Yes, the ports are connected to specific GPIO pins as you stated but are controlled by software for serial communication. I can't see how via UIFlow that you can treat the PBHUB as a standard GPIO.

Again now that I have commented that someone who is an expert will point out if I am correct or not to help you on your project 😉

@cerietke

@cerietke

Hi, I took a peek at openHASP and it looks like a lot of opportunity for HA.

I was hoping someone much more knowledgeable would hop in here to assist with the pbHUB because I am a bit confused how it works? I read the docs (which mentioned using PortB) and am still confused how to control a GPIO pin? With that said..

Why not use the GPIO pins directly? You can access the GPIO pins using the BUS Module? Part number is M024. I am using that module to interface LEDs, switches, rotary encoders directly to the Core 2 via the GPIO pins. You will need to solder the right angle header to the PCB and use an Xacto knife to remove some plastic.

Sorry if I am steering you in the wrong direction. I will pickup pbHUB next week to figure it out.

Keep us update on progress!

Hi all,

Some insights to share! Well the Active Low Pass filter did help to a small degree. With that said I decided to connect my Oscilloscope to the input of the ADC0 using GP35 and I was surprised by the amount of noise!

Input of ADC0 on GP35:
There was over 200mV of noise that varied in frequency of anywhere from 18 to 78MHz!

Measuring "ground" (just as a reference)
There was less then 100mV of noise that was around 60Hz which would be expected here in North America as our AC Line Frequency is 60Hz.

I did order some other one-wire temperature sensors including the DS18B20 and have another temperature sensor with a +_ 0.25 accuracy just to experiment with.

Again I will keep this post updated.

Thanks-Brian

Howdy Arno and thanks for providing the links...I did take a peek at those already!

I'll take a look at the DS18B20 but I already purchased the LM34s (Fahrenheit version). I think the LM34 has a bit better accuracy yet DS18B20 is the less "painful" alternative!

I plan to:

1. look into the whole atten as that controls the voltage range to the ADC
2. look into an active low pass filter using a single supply Op-Amp
3. look into adding a small gain from the Op-Amp to get the voltage from the LM34 into an acceptable range for the ADC

Will share my findings along with any schematics I come up with.

Thanks-Brian

@littlbee

Hi, sorry for your problems with burning...frustrating to say the least!

I would attempt to try repeating the process from another computer...is that an option?

Let's try to figure out if this is a communication error or a Core 2 defect?

Keep us updated!

Greetings everyone,

First I have really had a lot of fun exploring the Core 2 (my first M5Stack product)! A lot of features for under $50! My joy ended a little when I discovered the less then capable ADC functions which after doing a little research on the internet (and searching this forum) this seems to be related to the ESP32 processor.

With that said has anyone explored using a passive or active low-pass filter? My hope is that someone may have a schematic that someone would be willing to share?

The end-goal is to use a LM34 Temperature Sensor with the Core 2 as a thermostat for the radiant floor heating in my home.

Thanks ahead time if anyone can assist-Brian

PS: My first post to this forum :)