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Topic: 32u4 based APRS Tracker (Read 8322 times) previous topic - next topic

Brad Burleson

Jun 05, 2014, 01:12 am Last Edit: Jun 05, 2014, 01:21 am by Brad Burleson Reason: 1
Hey all... so here is something I've been working on the last month.   It's an APRS tracker based on the Trackuino firmware http://www.trackuino.org.

I took the Sparkfun Pro Micro Eagle files and immediately tossed the .brd file.  I then added a Radiometrix HX1 and a ublox GPS, and changed nearly all the parts to something a bit easier for me to deal with (which means 0805 mostly, there are a few 603/402 parts left).

Not shown is the daughterboard that connects between JP1 and JP2: I have both an LDO version and a boost converter version; each supply 5v.

As of right now it's running a custom bootloader and a port of Trackuino 1.4 by John Boiles (KK6GIP); though I'm in the process of integrating his port into Trackuino 1.5 and adding support for a microSD card.

Any comments would be appreciated.

Regards,

Brad
KF7FER

PS the photo's are of the old Revision "C" boards (where you can see how I messed up soldering JP1)

EDIT: I should add that I used the 3.3v/8Mhz version of the Pro Micro

liuzengqiang

Power to open source hardware! Thanks for sharing!

So you are using ATMEGA32U4-AU? Isn't sparkfun micro pro using the MU? I'm interested in working with this processor (AU so I can hand solder). Where did you get the EAGLE part? Just asking.

Oh, I guess you have 3 (or multiples of 3) purple boards for each revision? ;)

What about the micro SD slot? Would you be willing to provide some information?

I am using this one I got from dipmicro on one of my designs. The pins are not very long so I struggled a bit with it while learning (burning stuff of course) SMD soldering:

http://www.dipmicro.com/store/CON-MICROSD1

They are restocking in a week or so.
Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter

Brad Burleson


Power to open source hardware! Thanks for sharing!


No doubt!  And I'm glad to share.  After all, I wouldn't have gotten where I am without others sharing as well.

And talking about Open Source in general:  I got the inspiration to finally do a 32u4-based board from the work of KK6GIP (https://github.com/johnboiles/tinytrackuino) who did a port of the Trackuino 1.4 source from the 328 to the 32u4.

And just to say thanks for this work - which saved me considerable time -  I'll be giving him one of my assembled Revision "E" boards for the cost of shipping.

Quote

So you are using ATMEGA32U4-AU? Isn't sparkfun micro pro using the MU?


Yup.  I really like the 32u4 for the extra memory and the "free" serial port (is way cool to have 'Serial' for debugging and 'Serial1' for the GPS).  I do hate the $6+ cost (quantity 10) and it's limited availability (but I see the 328p is now over $3 in small quantities).

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I'm interested in working with this processor (AU so I can hand solder). Where did you get the EAGLE part? Just asking.


The TQFP part came from Sparkfun's library.  I see that Adafruit has it as well.

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Oh, I guess you have 3 (or multiples of 3) purple boards for each revision? ;)


Wonder how you knew that? :-)

Quote

What about the micro SD slot? Would you be willing to provide some information?


Certainly.  But I suspect you'll be disappointed because I'm using the same socket from the same vendor.  The footprint I found on these forums.  I'll do a follow-up posting tomorrow with a few pictures of the revision "E" board and the post the Eagle files that that time.

Quote

I am using this one I got from dipmicro on one of my designs. The pins are not very long so I struggled a bit with it while learning (burning stuff of course) SMD soldering:


Well there is a bit of a learning curve going SMD soldering for any new part.  If it would help, I've got at least a dozen unused PCBs with the 32u4 on one side and a microSD slot on the other.  I use 805 (mostly), 603 (4x LEDs), and 402 (3x) parts on this board.  Plus a SOT23-3, a SOT23-5, and even a 1206 part.  Plus 0.1" headers.

I'd be glad to give a couple of them to you (or anyone else) who would be willing to pay a couple of bucks (via paypal) for the shipping cost.  They won't work but are good to practice soldering on.  Heck I've got a few parts rattling around that I could throw in as well (some 0805 parts that fell on the floor and some others that I haven't bothered to re-use because they are unidentified).

You'd have to supply a sacrificial microSD socket and TQFP CPU but I thought it might help...

Regards,

Brad
KF7FER

liuzengqiang

Thanks Brad. I have SPE library so I'll dig into their micro pro board design as an entry point for myself. Thanks for the nice offer. I've got a dozen boards with 32 pin TQFP ATMEGA328P-AU myself. Did a board myself and learned a bit about SMD soldering (not as easy as in youtube videos). Hope my next revision will work.

Yes, ATMEL's processors are on short supply everywhere and digikey jacked up the price (very not nice). I will wait for mouser to make delivery later in the summer. No rush on this. Got other projects to take care of. I usually buy around 100 units (PDIP ATMEGA328P-PU) so I can get better pricing. It's only $3.50 if you buy 100 TQFP 32U4. We should stock pile these processors and periodically sell them here for nominal fees just to give digkey etc. the finger LOL

BTW, you are on the west coast. Your purple board delivery must be speedy :) My current board is too big and I'm cheap so I'm going with iteadstudio.com in China. 2 weeks is a reasonable wait for potential coasters.
Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter

Brad Burleson


I usually buy around 100 units (PDIP ATMEGA328P-PU) so I can get better pricing. It's only $3.50 if you buy 100 TQFP 32U4.


Smart.  I've been buying 25 units just to keep the cost down but you are certainly correct about the 32u4.  I should have bought more (especially seeing as how the TQFP version keeps going out of stock).

Quote

BTW, you are on the west coast. Your purple board delivery must be speedy :)


It's actually better than that.  I'm about 50 miles (or so) from where the boards are shipped.  In the old days I used to meet Laen at Starbucks for faster turn-around (there was a period a few years ago where he was able to offer less than 1 week turnaround if you could meet him locally).

So it's one day shipping for me.

Quote

My current board is too big and I'm cheap so I'm going with iteadstudio.com in China. 2 weeks is a reasonable wait for potential coasters.


I can understand; purple gets expensive for larger boards.  But two weeks from China is amazing; I thought they took more like  a month.

Regards,

Brad
KF7FER

liuzengqiang

Brad,

I pay DHL with the board purchase. So something as big as 4"*4" or 100cm^2 is about $65 for 10 pcs, with lead free etc. last time it was spring festival so I shelled out big money to get 21 8cm*10cm boards from OSH Park. It was speedy for what I was hoping for. Now to think about why your name sounds familiar, maybe you recommended Dorkbot PDX in the first place, some years ago, way before they took in BatchPCB or became OSH Park.
Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter

liuzengqiang

Brad,

I have a picture to share. I noticed that you also have some similar features on your board: the microSD card pins are off to one side instead of centered on the pads.



I wonder if there is any way to make some changes. If we shift all pads one way, the last one gets too close to the tab. If we make them smaller, darn, it's already difficult to solder. It works, but just not perfectly. Any thoughts?
Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter

cekuz

Dear all,
i'm a super Rookie, so sorry for the basic question (and for my ugly english).
I'm trying to understand how to connect the radiometrix hx1 to FLORA (based on 32u4 chip), expecially the radiometrix PIN 4. It's a PD4 XCK pin, but on the FLORA there isn't the exact corrispondence. Is it possible to link it to any digital pin? And the PIN 7, is it correct to link it to the Flora pin TX (PD3)?

thank you very much for your time

francesco

Brad Burleson

francesco-

Sorry for the late reply but to answer your questions (assuming you haven't solved them yet):

1. Pin #4 on the Radiometrix HX1 I've had great success connecting it to pretty much any free digital I/O pin.  No problems.

2. Pin #7 on the Radiometrix HX1... You'll want to connect this to a pin on the Flora that does PWM. 

I guess it depends on the software you're using.  I've been using John's modified version of Trackuino and the pins it supports for the HX1 is 6, 9, or 10 (I think maybe 13 but given how the firmware treats pin 13 you might want to skip that ;-) ).

Just to be clear, for the HX1 on my board I connected Pin #4 (on the HX1) to PD7 and Pin #7 to PB6.

I hope this helps a bit,

Brad
KF7FER




Brad Burleson


It works, but just not perfectly. Any thoughts?


Sorry I missed this.  Well, I think you're right - we could almost fix this but that last tab is a problem.  So by perfectly you mean it's not physically perfect, or functionally?

I'll have to double-check but as sorta hound-dog ugly as it looks, it does seem to work.

I'm thinking to just leave it be because I hand solder the backside of my boards and this - and the transmitter - is on the back.

Belated regards,

Brad
KF7FER

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