Electronics > Projects, Designs, and Technical Stuff
Issues programming NXP LPC11U34
Headless Chicken:
Hi all,
I’m currently stuck on a kind of a problem, and I’m unable to make head or tails of where the it could be.
So, the setup is the following, it’s some kind of USB gizmo using the NXP LPC11U34-421. I have made a custom dev board for it but note that for reasons :-\, the pcb does not include the crystal and it’s now bodged as close as possible on top of the chip.
The idea behind picking that chip was to save me the hassle of writing my own usb bootloader and just use the integrated one. First problem: I just cannot manage to boot into it, the USB device keep showing up as unrecognized and not MSC on the computer, even when I tried pulling the PIO0_3 to high and pressing reset (PIO0_0) while keeping the bootloader switch (PIO0_1) pressed as per the documentation, but nothing, still unrecognized.
It’s my first time dabbling with usb so I’m not sure what to expect but using a USB analyzer I got some up and down traffic going on the bus. Here is an extract:
• IRP_MN_QUERY_DEVICE_TEXT (description) for which the device (?) answered not supported
• IRP_MN_QUERY_DEVICE_TEXT (location) for which the device (?) answered its port and hub location
So that last one got me thinking maybe it’s not the device answering but something in the middle (the hub?) as I have yet to flash anything on the chip. The D6 LED on the Soft Connect D+ Pull up is lightning up as soon as I plug in the USB.
So I figured, maybe the chip does not have the USB bootloader ready to use out of the factory, and I would hook up the BM probe to it to try flashing it through UART but then again to no avail, I got a “attaching to remote target failed”. Putting a logic analyzer on the RX TX lines showed me that no traffic was going through :o. I’m using PlatformIO set up to use the BM probe. I have not done anything else, no further installation. Is there any further setup required, it seems however to detect the probe just fine.
I am currently at a point where I’m not sure if that part is fried, if I’m using the tools correctly, or if something is wrong in my board design.
I would be very glad if someone could help me figure out what's wrong there!
Best,
iMo:
Try to remove the D6 LED.
https://os.mbed.com/media/uploads/andersonj55126/an11305v.1.pdf
Headless Chicken:
Hi Imo,
Thanks for your answer, I tried to remove D6 and connect the USB but the result is the same.
I came across the document you sent before, but sadly I'm blocked in the middle of the second section, and that is the procedure I am following.
iMo:
--- Quote ---Once ISP mode has been entered, the USB VBUS line PIO0_3 is checked. If high, then USB ISP will be entered. If low, UART ISP will be entered instead.
--- End quote ---
Your PIO0_3 is floating, afaik..
Place a 10k pullup there..
Headless Chicken:
I haven't included the full schematics but PIO0_3 pin is connected to a header with a jumper wire to VCC.
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