proper way to use echo_id

[brandonros]

async sendCanFrame(arbitrationId, data) {
    const frame = Buffer.alloc(0x14)
    frame.writeUInt32LE(0xFFFFFFFF, 0x00) // echo_id
    frame.writeUInt32LE(arbitrationId, 0x04) // can_id
    frame.writeUInt8(0x08, 0x08) // can_dlc
    frame.writeUInt8(0x00, 0x09) // channel
    frame.writeUInt8(0x00, 0x0A) // flags
    frame.writeUInt8(0x00, 0x0B) // reserved
    frame.writeUInt8(data[0], 0x0C)
    frame.writeUInt8(data[1], 0x0D)
    frame.writeUInt8(data[2], 0x0E)
    frame.writeUInt8(data[3], 0x0F)
    frame.writeUInt8(data[4], 0x10)
    frame.writeUInt8(data[5], 0x11)
    frame.writeUInt8(data[6], 0x12)
    frame.writeUInt8(data[7], 0x13)
    return this.device.transferOut(this.outEndpoint.endpointNumber, frame)
  }

When I write a CAN frame over USB, it gets echoed back to me. Is there a way to not do this?

[fritz-net]

as i remember it is not echoed, it gives the frame on the bus with proper time (which is a very helpful feature - I think youre writting a driver impl for js as i remember, i would keep this feature). The easiest solution would be handling this in your wrapper.

[brandonros]

it is echoed in the sense that if i TX a packet, i RX it right back. is there a way to filter RX packets based solely on what the device actually receives? i’m doing UDS flashing and the response times/bandwidth are being affected by the fact that whatever I TX, I RX Regards, Brandon

…

________________________________ From: fritz-net <[email protected]> Sent: Friday, May 22, 2020 4:44:01 PM To: candle-usb/candleLight_fw <[email protected]> Cc: Brandon Ros <[email protected]>; Author <[email protected]> Subject: Re: [candle-usb/candleLight_fw] proper way to use echo_id (#50) as i remember it is not echoed, it gives the frame on the bus with proper time (which is a very helpful feature - I think youre writting a driver impl for js as i remember, i would keep this feature). The easiest solution would be handling this in your wrapper. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub<#50 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ACEJBFSV6UQCEOYUPZIALWLRS3PZDANCNFSM4NICCY2Q>.

[fritz-net]

as i know there is no possibility in the gs_usb driver to disable this. Are you sure the bottleneck is USB? If your dive does not replay with the exact same frame you could filter your tx in your wrapper/driver (save last TX -> compare (with timeout) -> ignore)

Someone is writing on a new version of this Firmware, he wants to adopt the driver as well to support CAN fd, maybe talk to him (don't know who atm)

[brandonros]

Am I supposed to reset and start 2 channels? 1 for read, 1 for write?