• What are the Code Read Protect (CRP) levels on the LPC17xx?

    Code Read Protection allows users to enable different levels of security in the system so they can protect both their software code and hardware. There are several methods to program or read the Flash Memory: - JTAG...
    LPCware Support
    last modified by LPCware Support
  • How to use swim_put_image function in the code?

    Once you've created a SWIM window, there are several image related SWIM functions for placing image data into a window. Before you can use those functions, you need to have a 2D array of pixel data in the LCD's native...
    LPCware Support
    last modified by LPCware Support
  • LPC1347 USB Control Transfer

    Our customer SIGMATEK wants to implement USB Control Transfers on the LPC1347. This works nice as long as they have a data length of less than 64 or more than 64 Bytes. If the data length is exactly 64 Bytes (or a ...
    Peter Furtner
    created by Peter Furtner
  • Where to get LPC mcu ROHS report?

    Dear,   Where to get LPC mcu ROHS report for below Part number? Thanks.   LPC2114FBD64 LPC2136FBD64 P89V51RD2FBC
    Hanson He
    created by Hanson He
  • emWin支持哪些编译器/IDE?

    恩智浦在LPCware.com上有ARM/Keil, IAR, Rowley Crossworks和LPCXpresso的安装包。如有需要,以后会添加对其他编译器的支持。
    LPCware Support
    last modified by LPCware Support
  • How can I verify the configured CAN bitrate, using an oscilloscope?

    CAN frames do not guarantee an edge appears for every bit. There can be sequence of up to five consecutive bits of the same logic level with no edges appearing in the waveform. If the bus is operating normally and fra...
    lpcware
    created by lpcware
  • The CAN controller goes into bus off mode when my application tries to send a CAN message. There is no activity on the CAN bus. Why?

    There are many causes of this and all relate to an issue between the CAN controller and the bus. For example no CAN transceiver, CAN transceiver disabled, broken connection between the CAN_L/H pins and the CAN control...
    lpcware
    created by lpcware
  • I see error frames on the CAN bus whenever my code starts up, before the CAN controller is initialized. What is a common reason for this?

    The most common reason is that the CAN_TX pin has been set to logic zero before the CAN controller is initialized and enabled. Even a brief period can cause a burst of error frames. Set the pin state to logic one befo...
    lpcware
    created by lpcware
  • How can I test the CAN peripheral and driver without a CAN transceiver and CAN bus connected?

    Use the internal loopback feature of the CAN controller. This allows the controller to receive what it transmits without the bus being used. Typically this mode is enabled by setting a bit in the control register befo...
    lpcware
    created by lpcware
  • Why does CAN0 work and CAN1 not work? Do I need another node to test my code?

    The CAN bus can only function if there are at least two CAN controllers on the bus. One to send and one to acknowledge. If a CAN controller attempts to transmit frames with no other nodes on the bus then the frames wi...
    lpcware
    created by lpcware
  • Can I wake up the part on CAN bus activity?

    This depends on the microcontroller used and what wakeup sources it allows. LPC1800/4300: the event router allows wakeup via CAN from sleep mode. It allows wakeup from other power modes through the wakeup pins therefo...
    lpcware
    created by lpcware
  • What is the difference between error active and error passive?

    CAN controllers initialize into error active state. Although this state has the word “error” in the name it doesn’t mean there is an error. It means that the CAN controller can actively send error fr...
    lpcware
    created by lpcware
  • How do I detect there is no CAN bus connected?

    If there is no CAN bus then each attempt to transmit a frame will fail and the transmit error counter will increase. The error counter can be read before and after transmission. In addition CAN controllers typically p...
    lpcware
    created by lpcware
  • Can I send a message with X/Y/Z bits in the ID?

    Message identifiers are either 11 bits or 29 bits in length. No other length is supported.     "FAQ contribution from Embedded Systems Academy, experts in CAN bus. For more information visit www.esacademy.com"
    lpcware
    created by lpcware
  • How is the transmit error counter reset?

    The transmit error counter cannot be manually reset. It is part of the error detection and handling mechanism of the CAN bus. If the error counter is continually increasing then it indicates a problem with either the ...
    lpcware
    created by lpcware
  • What is the sample point for?

    The sample point is the location, typically given as a percent value, inside each bit period where the CAN controller looks at the state of the bus and determines if it is a logic zero (dominant) or logic one (recessi...
    lpcware
    created by lpcware
  • How do the error counters work?

    Every CAN controller has two error counters, one for transmit and one for receive. These error counters are nearly always made available to read by firmware and when certain events happen there are usually flags in re...
    lpcware
    created by lpcware
  • What are the benefits of integrated CAN transceivers?

    Microcontrollers with on-chip transceivers allow for solutions that are more compact, reliable and cheaper. In some cases transceivers can cost more than the microcontroller they are connected to. Reduced PCB space me...
    lpcware
    created by lpcware
  • What is CAN-FD?

    CAN-FD is a new CAN bus frame format, developed by Bosch. The current version was also published as an international standard ISO 11898-1:2015. It allows for up to 64 bytes of data per frame and significantly higher b...
    lpcware
    created by lpcware
  • How to detect and handle bus off?

    Bus off means that the transmit error counter (see explanation further down) has reached 256. There are many possible causes of this but it could mean that the CAN controller is misconfigured or the controller is not ...
    lpcware
    created by lpcware