lpc11u24 isp programming - costum pcb

Topic last updated 13 Aug 2012, by user Hermann Helmholz. 3 replies tag ISP, LPC11U24
user Hermann Helmholz
12 Aug 2012

Greatings,

A month ago I was playing with a costum PCB for the lpc11u24. I did not have any time so I droped the project for a while. Now I am working on it again. I bought a QFN64 PCB and soldered a lpc11u24 on it like this : /media/uploads/RFID/_scaled_img_20120812_153317.jpg

Than I connected the pins to my mbed 11u24 like this,

MBED       ==connected to==  IC
#################################################
p30(isp)   ==connected to==  PIO0_1 (pin 5)
p29(reset) ==connected to==  RESET/PIO0_0 (pin 4)
p9(TX)     ==connected to==  RXD/PIO0_18 (pin 61)
p10(RX)    ==connected to==  TXD/PIO0_19 (pin 62)
GND        ==connected to==  (pin 19)
VOUT       ==connected to==  (pin 10) 
GND        ==connected to==  (pin 7)

and upload the code from http://mbed.org/users/chris/notebook/prototype-to-hardware/ while carefully changing the pins if necessary. I double checked everything. For now I am only trying to get the synchronized message from the lpc11u24 without succes. I did not use any capacitors because I am powering the lpc11u24 directly from the MBED (I guess it is safe...).

For now it is not working. I guess I am missing something important...

any hint would be great.

Thanks.

Replies

user ceri clatworthy
13 Aug 2012

From the photo i cannot see, BUT, have you fitted a 12.00MHz crystal, with its own caps (12pF * 2)

I have been promising myself to do this with LPC11U24,

/media/uploads/ceri/_scaled_imag1369.jpg

But i did make this one earlier. (in true blue peter fashion)

Ceri

user Hermann Helmholz
13 Aug 2012

Hi Ceri,

thanks for your reply. I am glad to see that you have made a similar board. To answer your question, I did not use a crystal because this is only for usb porgramming (as far as I understand) and I am trying to use the ISP.

By the way, tell me Ceri, it seems like you are not using caps on your board (so do I for now because I just want to test...) It seems like, there is no big problem... Isn't it?

thanks.

user ceri clatworthy
13 Aug 2012

you should always. use caps

/media/uploads/ceri/_scaled_imag1646.jpg

probably. not too clear but they. are there

but they. are there look at the second photo the blobs that look like shorts... actually 0402 Caps. B-)

I think USB Programing needs a crystal, serial programing might not ???

I think there's. another thread with details of it

hope this is usefull!

Ceri /media/uploads/ceri/_scaled_imag1363.jpg

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