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750c Display Documentation

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    #76
    waste of time
    Last edited by stts; 03-24-2023, 02:56 PM.

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      #77
      waste of time
      Last edited by stts; 03-24-2023, 02:56 PM.

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      • paxtana
        paxtana commented
        Editing a comment
        Fogging has not been an issue on 750c for a very long time. It was due to assembly in less than ideal conditions during one of the first if not the very first batch off the production line. They fixed it years ago.

        Only bafang display with a bt smartphone app is eggrider

      #78
      Hi, hopefully this information is useful for everybody.

      I have found 2 different simple methods of extracting the pin/password from the 750c in case of lost or forgotten situations.

      My friend forgot his pin and asked me to help retrieve it.

      Open the display using the directions in the thread so you have access to the PCB.

      There should be a small 8 legged eeprom chip next to the stm32 MCU.
      The eeprom should be labeled 24LC04.

      You have 2 options depending on your ability to solder.

      Option 1 is to de-solder the chip and read the data with a chip reader (see amazon pic below)
      You will need to set the data to Big-endian, the pin code can be seen in the screenshot below.

      It shows 1A 30. When you convert these bits to decimal, you get 26 48. The bits should be converted separately.

      The 2nd option is to use a cheap logic analyzer (see amazon below)

      You need to attach the clips to pins 6 and 5 of the eeprom (SDA, SCL) and GND

      A 24v power supply also needs to be connected

      I won't go into how to setup the logic analyzer software, there is plenty of tutorial on YouTube. You need to setup an I2C protocol.

      Once set up, start the analyzer and turn on the display. You will see a short burst of data.

      Filter the results to show only data and the pin will be displayed in the same hex format (as circled)
      The write section refers to the location in the eeprom (7E 7D 7F)
      the read lines refers to the useful data
      So you only need to look for the data at 0x7E and 0x7F

      1A 30

      Convert the bits to decimal and you have your pin.
      Attached Files
      Last edited by BenTen; 04-27-2023, 07:16 AM.

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      • Andrewol
        Andrewol commented
        Editing a comment
        Hi. Do you know why this display has high overvoltage reading, over 6V than actual value?

      #79
      The 1919 lock code on my display 750c doesnt work why?

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        #80
        Originally posted by Pauli gualtieri View Post
        The 1919 lock code on my display 750c doesnt work why?
        Try code 1199

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        • Pauli gualtieri
          Pauli gualtieri commented
          Editing a comment
          I already tried but it doesn't work

        #81
        My DPC-18 display died so I bought a 750c because it displays the watts nicely. However when I ride at a steady power, I noticed the watts display jumping between two values about 50 watts apart. When I select PAS of 100%, the power reads 1.5 kW, which is ok for full scale. But when I select PAS level 10%, I get flicking between 112 or 168 watts, which is not ok at that end of the scale. I expected a much more accurate indication of my power.

        So I switched to current and found that the current display resolution is in whole amps! Anyone else noticed this? The 112 and the 168 is either 2 amps or 3 amps times the battery voltage. So they just multiply the whole amps by the battery voltage to get the watts. That's really poor software engineering. Current should have had a resolution of 100 mA or better. Then it's just a matter of correct filtering to get a steady but accurate readout of either current or power.
        Last edited by eRider; 06-30-2023, 03:38 PM.

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        • AZguy
          AZguy commented
          Editing a comment
          The displays just put out what the controller is reporting and it's poor resolution, update speed, etc. makes them almost pointless

          There are third party units where a shunt is installed inline upstream of the motor that give very good numbers and some will log and do amp-hour/watt-hour totalizers... much better solution if the data is important to you

        • eRider
          eRider commented
          Editing a comment
          Oh ok, thanks

        #82
        Hello,

        So I am trying to connect my 750c to my FarDriver 72360 controller and I was wondering if anyone had an idea how to do that given the parameters in the Bluetooth app (I’ll attach a picture). The controller has transmit and receive wires coming out of it that go to the Bluetooth receiver, and also has a digital speed pulse wire. Any help would be appreciated!

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        • paxtana
          paxtana commented
          Editing a comment
          750c does not have bluetooth and I never heard of that controller; generally speaking displays are not compatible with other random controllers as they use varying communication protocols
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