Don't know what to use



  • Hello,

    I want to build some kind of automated pet food dispenser using 3D printed parts and M5stack

    The concept is:

    • My pets (cats) will have an RFID chip on their collar (so that only my cats will get food distribution)
    • When they come close enough to the dispenser; I will use M5stack RFID2 to detect them and trigger food distribution
    • Food distribution will be done with a DC motor; rotating a big screew
    • I will use a M5stack scale kit to detect the food quantity in the bowl (the DC motor will only rotate if the food level inside the bowl is bellow the treshold)

    Currently; 3D parts are OK, scales kit programmation is OK, rfid2 programmation is OK

    I still have several problems to solve and not sure about the way to go:

    • I need an M5stack core to host the code that will manage the dispenser (I have Echo, Stickc-PLUS, Basic Core)
    • I need a way to make scales kit + RFID2 + DC motor communicate with the core
    • I need to find a way to control the DC 12V DC motor (I have a DC motor module for Core; but don't know how to wire the motor. Do I need to use another module like the GoPlus 2 ?)

    Some advice would be greatly appreciated from you guys :)

    Thak you for your help
    Best regards

    I'm not sure about



  • Hello@jerome83136

    Make using the following products.

    Smart Food Dispenser Pets New Inventions Cat Puppy Timing Feeder Microchip Rfid Automatic Dog Plate

    https://www.alibaba.com/product-detail/Smart-Food-Dispenser-Pets-New-Inventions_1600508280273.html

    https://www.aliexpress.com/item/1005004305910681.html

    https://www.aliexpress.com/item/1005004313818854.html



  • What motor module have you got and what have you tried so far?



  • @macsbug hi,
    Thank you but I want to make it by myself rather than buying a plug&play product.
    Regards



  • @ajb2k3 hello,
    At the moment I have a h-driver for Atom
    I was able to control the 12v DC motor by using this module; but I think I will not be able to use the Atom for communication between the scales kit+RFID emitter (because I only have 1x grove port on it)

    I also have a M5 core and a DC motor module; but don't know how to wire the DC motor on it

    I'm still learning so I don't know if these information are sufficient. If not; I will be happy to provide more details about my setup and the hardware I have got. Feel free to ask.

    Thank you very much for your help 🙂
    Best regards



  • Hi guys,
    Somebody able to help on this? 🙂



  • Sorry forgot about this.
    You should be able you use the Scales and the RFID units on the same port of the atom if you connected a PaHub between them as they both use I2C to communicate and the PaHub is an I2C port expander.
    Have you tried testing with the RFID or the scales kit connected ?



  • @ajb2k3 hello,
    That's a good news if I could use only the Atom rather than a M5 core; because I don't need any display and I prefer to keep things minimalist 🙂

    I unfortunately did a mistake about my available hardware: I don't own a Pahub but a 1 to 3 HUB Expansion Unit
    I think it won't work.
    I will order a Pahub and post any progress here.
    Thank you for your great help !

    As I'm going to order things at M5stack, I also would like to order the required parts for controlling a 12v DC motor with a M5 Core

    What kind of module/extension should I choose for this ? GoPlus2 maybe?

    Thank you for your feedback

    Best regards



  • You said you are controlling a motor with the ATOM already, what motor and atom are you using. Please share photos of your setup so far.



  • @ajb2k3 here is a photo of my setup with:

    • Atom + h-driver
    • 12v DC motor
    • 12v power supply

    link text

    What kind of module/extension should I choose for this ? GoPlus2 maybe? --> this question was for another future protect with a 12v DC motor I want to control with a M5 Core. This is just for information and is not related to the subject of this topic 😉

    Best regards



  • If its working as is then all you need is the Pahub to connect your two sensors and then program it all up.



  • Hi @ajb2k3 thank you for your feedback.
    I will order a Pahub and report any progress here.
    Best regards



  • One last question please

    I will need to get the level of food available inside the food tank
    For this, I plan to use a Ultrasonic Distance Unit I2C (RCWL-9620)
    I already have it

    Is it the correct way to achieve this ? (There are a lot of sensors for liquid level; bit not sure about what to use for solid things)

    The Ultrasonic Distance Unit I2C (RCWL-9620) is communicating with I2C. Does it mean I can connect it with everything by using the Pahub I'm about to order ?

    Thank you very much for your feedback
    Best regards



  • @jerome83136 you work great!



  • @ajb2k3 if it means this setup will work, then I'm happy 🙂



  • Unless you need to control the speed and direction, you can control a non-stepper motor with just a transistor and diode, for one speed, on-off type operation.

    Also bear in mind that the range of the RFID 2 Unit (WS1850S) is only about 20mm. The UHF RFID Unit (JRD-4035) had a longer range, but is expensive. There may be longer range 13.56 Mhz sensors available from other vendors.



  • hi @wsanders
    If I can drive the motor with tha Atom and H-driver; that's fine for me.
    I plan to extend it with a PaHub in order to get additional grove ports and connect the Scales kit + RFID2 reader.
    But I wonder if it will work because I'm not sure M5 Scales kit is using I2C

    I choosed the RFID2 reader because of its price (as you said: the UHF reader is quite expensive)

    I see 2 options to solve the range issue:

    • Using 3 RFID2 readers on each side of my object (see red arrows on enclosed picture)
    • Try to extend the RFID2 range with a custom antenna with magnetic wire, around the food dispenser
    • Use this cheap 125KHz RFID reader and make a custom antenna with magnetic wire, around the food dispenser. But can I make it talk to M5 stuff ? (it uses a grove connection and output format is Uart and Wiegand)

    Do you think it could work ?
    Thank you for your feedback

    Best regards



  • The RFID Unit is a I2C device. The scale unit isn't. Is uses a special protocol (using HX711 library). It will not work with the PbHub. As I mentioned in another community thread, you can get a I2C scale kit from DfRobot : https://wiki.dfrobot.com/HX711_Weight_Sensor_Kit_SKU_KIT0176.
    DfRobot doesn't use the groove standard fot their wiring: VCC and GND are switched as well as the SDA and SCL lines.
    Wish List for M5Stack: Make the scale kit I2C compatible by using the STM8/32 or AVR328 as they are using in the PbHub or 4Relay Unit making the compatible for the "universal" I2C bus.



  • Hello all,

    Some news here.

    I ordered an RFID reader and am still waiting for it to be delivered. So, I will share some news about this part later.

    For the 12v DC motor control; I have some troubles.
    I ordered a GoPlus2; but it tidn't feet because even if it has a 12v input; it can't deliver 12v output to my DC motor.

    So I switched to another option: using a 5v relay to power the 12v DC motor.

    The problem I have is: how to use the M5 Core to control the 5v relay ?

    I tried this example but I'm just unable to understand what are the pins used by this guy on the M5 core ?
    The guy uses the pins 2, 27, 32 and 13; but where are these pins on the M5 core basic I own ?
    Do I have to remove the M5 core bottom (received with the M5 core basic) ?

    I don't really understad the pin map of the M5 core basic. Is there some reference somewhere for wiring ? And is there a description about the colours used on the M5 core basic product sheet pinmap section ?
    Or some example telling "if you are using digitalWrite(2, 0) on UIFlow; you have to use this specific pin on the core"

    Thank you for your feedback

    Best regards



  • The pinouts are located on the M5Stack product page by following the documents link https://docs.m5stack.com/en/core/basic_v2.6?ref=pfpqkvphmgr
    The exact pins and location depend on the specific model of core but he is using the Core2's MBus which is the big internal connector.