Title: xQFP breakout board Free PCB build
Post by: matseng on October 15, 2011, 07:57:12 pm
Post by: matseng on October 15, 2011, 07:57:12 pm
One of my current (pending) projects is a 16 step 8 channel sequencer/drum machine. For some early prototyping I needed a usb-capable AVR so I took one of the xQFP breakout boards I once upon a time managed to get from the Sunday Free PCB giveaway.
Instead of just putting the chip on the board I went a few steps further. On the PCB there are now the mini-USB connector, a 3.3 volt reg, power fully wired up and decoupled, a power led, a (non smd crystal and it's capacitors), the two 22 ohm resistors, a reset switch and finally the boot loader (HWB) switch.
I used pins from some old wirewrap sockets and used them as connectors. They are great to put those tiny and cheap male-male cables into.
[attachment=1]
The sequencer will look something like this when it's ready. Eagle3D didn't have the correct parts for the usb connector and the headphone jacks so disregard the looks of those. In the gray area in the middle will be cut out and a 8x2 character LCD inserted from below.
[attachment=0]
Instead of just putting the chip on the board I went a few steps further. On the PCB there are now the mini-USB connector, a 3.3 volt reg, power fully wired up and decoupled, a power led, a (non smd crystal and it's capacitors), the two 22 ohm resistors, a reset switch and finally the boot loader (HWB) switch.
I used pins from some old wirewrap sockets and used them as connectors. They are great to put those tiny and cheap male-male cables into.
[attachment=1]
The sequencer will look something like this when it's ready. Eagle3D didn't have the correct parts for the usb connector and the headphone jacks so disregard the looks of those. In the gray area in the middle will be cut out and a 8x2 character LCD inserted from below.
[attachment=0]
Title: Re: xQFP breakout board Free PCB build
Post by: Sjaak on October 16, 2011, 03:13:20 pm
Post by: Sjaak on October 16, 2011, 03:13:20 pm
Cool!
I started disappointed when I saw the topic title, but was surprized when I saw the picture.
I started disappointed when I saw the topic title, but was surprized when I saw the picture.
Title: Re: xQFP breakout board Free PCB build
Post by: matseng on October 16, 2011, 03:51:17 pm
Post by: matseng on October 16, 2011, 03:51:17 pm
That's true... The boring title really doesn't make the messy cluster of soldered parts any justice. I'll think I re-title it to "A sh*tload of parts stuffed onto a free breakout pcb" :-)
But the board actually worked the first time I powered it up, now I just have to keep it from breaking. Maybe to hotglue to keep the wires in place might help with that.
But the board actually worked the first time I powered it up, now I just have to keep it from breaking. Maybe to hotglue to keep the wires in place might help with that.