High Level Question regarding M5Stamp and Core2

  • I have an application that I think may be a perfect fit for using the M5stamp modules along with a Core2 module but I'd like to make sure I am understanding the capabilities of the product before I go too far down the rabbit-hole. I have a large number of devices (10-20) that I would like to monitor, temperature, for example. I don't need high frequency sampling, perhaps checking every 15mins and I would like to have them run off a battery. I think the stamp would be perfect for this as it has low energy usage and a small footprint. All these device would be in about a 50meter range. I am thinking a Core2 module, using WIFi could act as a "server" to receive data from the various stamps and act as hub for looking at the data and sending alerts if problems arise. What I want to know is if this seems like a reasonable application for the two products. I believe that WIFI would probably be the best communication protocol because of the distances that I am needing. I could add more Core2 devices to reduce the overall distance if the range is too great.
    This will be a learning project for me because I have just started playing with the products and have never done projects with wireless communications before so I am also wondering if there may be a better choice. I believe I need more range than Bluetooth or ESP Now can cover but I am not sure if that is accurate. I have not seen a lot of project examples using the stamp that is some of the source of my concern that it may not be the right product.
    I would appreciate any input/advice that any of you have. Please understand I'm not asking for specifics of how to do it, just to make sure that it can be done. Learning how to do it is the fun part but like most people, there is only so much time in the day and I don't want to squander it chasing something I should have never pursued to begin with.

  • I should also add that I do not have an internet connection available so using a cloud service would not be feasible. I am also thinking that there may be more support and examples for the core box such as "ESP32 Basic Core IoT Development Kit V2.6" so I purchased one to use in place of the Core2 as a starting point. I Really love the M5stamp concept though and would like to try to make this work.

  • Hi, I have a Core Basic HVAC program communicating with two Stamps using ESP_NOW and they are physically close, but the idea was to not run messy cables! The ESP_NOW is peer to peer WiFi, but no login to the internet or even the WiFi router.
    One Stamp reads the HVAC vent temperature and reports to the Core, which in turn calculates the damper vane angle and transmits that back to the very same Stamp connected to a 180 servo motor.
    The other Stamp just operates one or two small under desk heaters as required, by the Core.
    Hope this helps.

  • @teastain That does help and I may have not fully grasped that ESP_NOW was. It may have a better range than I was expecting and it does look much easier to get setup. Your application sounds like the same type of framework I am wanting to do, although I am not anticipating any motor control at the moment. Out of curiosity, how far are the stamps away from the Core Basic module. The under the desk ones are also interesting because I was wondering how they would do if there was some physical (especially metal) barriers in the transmission path.

    Thank you again for getting back to me, I greatly appreciate the input,


  • Hi Thomas. The desk is wooden.
    But you can expect typical range and "through walls" of a WiFi router in your house.
    WiFi uses quite a bit more current than you might think.
    I run mine on 5V iPhone white cube USB power supplies.

  • I wanted to follow up to let you know that your recommendation of using ESP_NOW was spot on. It was very, very easy to set the Stamp and the Core2 to talk and the range is beyond what I am going to need. You are correct about the current usage but it won't be a problem to access power for the units so I won't have to rely on batteries. As you indicated it is messy running cables between all the units but a the power connection is pretty compact. I am really impressed with these products and, again, am very grateful for your thoughts and advice.

  • Thomas, so glad to help, I love ESP_NOW !!!
    All my maker stuff is now M5Stack!
    Cheers, Terry