Don't know what to use



  • 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.



  • Hello,

    Thank you for your feedback.

    As I'm quite new on this kind of stuff (using pins to interact with an external component); I need some tips :)

    When I do this on UIFlow:

    0_1678191762463_6e270bbe-7ab0-4684-beca-fb73b770b123-image.png

    I understand it activates the pin n°2 (LOW), when the "switch0" is activated. Am I right ?

    How can I identify the pin n°2 on my M5 Core basic with a base core bottom ?

    I think I need some documentation/tutorial to understand the correspondance between the pins used into UIFlow and the the pinmap on M5 Core Basic. Can I find this somewhere ?

    Thank you for your help

    Best regards



  • Hi,

    I finally got the relay working with M5 Core Basic !
    I think my mistake was to power the relay with 5v rather than 3.3v

    Here is my wiring:

    0_1678303871852_e3effaca-5d50-4aad-8ac3-443c74b7346f-image.png

    And here is the example UIFlow that works for me:

    0_1678303823556_4a5396f9-008d-4831-9ef2-9a8450709bfe-image.png

    Now I need to find a way to power the M5 Core Basic by using a DC 12V --> USB 5V connector and connect it to the DC 12V power supply I already use.

    Next step will be the hardest: understanding how PaHub works to interconnect the M5 Core Basic with:

    • RFID reader
    • M5 Scales kit
    • M5 Ultrasonic Distance Unit

    I will report progress here

    Thank you again for your help

    Best regards



  • Hi all,

    Another report here.

    Almost everything is ready.
    I'm quite sure the RFID2 reader won't do the job because of its short reading range; let's try and improve if required.
    I will certainly have to give this reader a try. (already ordered)

    1 question I had while testing: TOF and RFID2 seems to need Ports A or E. But Port E never worked (the unit is seen as "not connected" by the Core); forcing me to use a PaHub which is a pity because I have plenty of available ports with the ExtPort extension.
    Someone able to help me understanding why ? (If I could use port E; I could completely remove the PaHub)

    Here is the current setup:

    0_1678322286834_643f4d48-949f-493f-a645-6ab5b9b233e5-image.png

    Last thing to do to complete the prototype: get a 12v --> 5V USB connector in order to power the M5 Core + 12v DC motor with a single source.

    Here is a simple UIFlow to check every component works correctly:
    0_1678322444056_88f378cd-ffb9-49e4-ae76-58ec1ab68f26-image.png

    Best regards



  • Hello all,

    Last part done (single power supply for M5 core + DC motor)
    I was also able to remove the PaHub by using the ExtPort (Port D). I had to change the dip switch value to:

    • Port D-1[2] = ON (to use GPIO22)
    • Port D-2[2] = ON (to use GPIO21)

    I then had to change the TOF module's port config in UIFlow to use the Port D:
    0_1678466335229_c91cfd3f-7455-44c5-bacd-6b80446df4c2-image.png

    Final diagram:
    0_1678466025476_23c67135-ad74-4585-9038-6379f178683c-image.png

    NB: DC(12v) to USB(5v) converter link

    Now let's get physcal parts printed and test it !

    Best regards



  • Cool and thanks for sharing your progress.
    When you get everything up and running, please create a build log on Hackster.io



  • Hi guys,

    New problem here: I'm unable to use this RFID reader from Seeed studio

    The reader is able to communicate by serial (9600 baudrate, 8 data bits, 1 stop bit, and no verify bit)

    I connected it with my Ext port Blue port PortC (stacked with my M5 Core Basic)

    • Reader Yellow wire (TX) --> Ext port (Port C) / PIN13
    • Reader White wire (RX) --> Ext port (Port C) / PIN14

    On UI Flow I tried this:

    0_1679067565637_9b0cde45-1a62-4fe4-866f-a0a6c3ccfc52-image.png

    When I put an RFID tag on the reader; a red led seems to indicate it detects the tag; but I get nothing printed on my M5 Core Basic screen.

    What did I wong ?

    Thank you for your help

    Best regards



  • Hello,
    Anybody here to help me on this blocking point?
    Thank you
    Best regards



  • @ajb2k3 hello,
    I would be really happy to share my project; but for this I will need some help on my last question on this topic 😉
    Any suggestion to unblock me ?
    Best regards



  • Have you got a micropython library installed for the reader?
    It looks like you set up the connection but you have yet to initialise the reader and tell it to start talking.



  • Hello,

    Thank you for your feedback.

    The code generated by the UIflow example from my last screenshot is the following:

    from m5stack import *
    from m5ui import *
    from uiflow import *

    setScreenColor(0x222222)

    lcd.fill(0xffffff)
    uart1 = machine.UART(1, tx=14, rx=13)
    uart1.init(9600, bits=8, parity=None, stop=1)
    while True:
    if uart1.any():
    lcd.print((uart1.read()).decode(), 0, 0, 0xff0000)
    wait_ms(2)

    Do I need to add something else to this code to receive any signal from the reader ?

    Do tyou mean UIFlow requires additional libraries to be able to communicate over serial (UART) ?

    Thank you for your help
    Best regards



  • Hello @ajb2k3

    I took a look on your UIFlow handbook for some examples on serial communication.

    I found this:
    0_1680074762436_101c0ef1-393b-4e13-9081-d0d4be3f153c-image.png

    It seems the code is almost the same than the one generated for me by UIFlow.

    The imported libraries are the same than the ones I have in my code:
    from m5stack import
    from m5ui import
    from uiflow import

    On the example provided by my reader's provider; they import this library: " #include <SoftwareSerial.h>"

    https://wiki.seeedstudio.com/Grove-125KHz_RFID_Reader/#play-with-arduino

    But I think this is the implémentation for Arduino and I guess the equivalent UIFlow libraries are loaded through this:
    from m5stack import
    from m5ui import
    from uiflow import

    Do I miss something ?

    On my side I think the reader works because when I bring a RFID tag close to it; the status led of the reader lights up.
    But I still receive nothing on the M5 core RX PIN

    Thank you for your help
    Best regards