Optimized transmit buffer, started hooking up MODE button

I've modified the Dexter program a little bit so that the transmit buffer gets emptied using interrupts rather than polling to see when it's time to send another byte. This should have the effect of faster transmit speed. It also may throw off critical timing so I will have to do some tests and may have to disable it if it is a problem.

I also started hooking up the MODE button to make the LDP choice cycle when you press it. This is not finished yet.

I've finished soldering my rev2 prototype board!

I've finished soldering on all the parts (well except for the JTAG pin headers which I don't have due to a shipping error with digikey). As you can see, all of the LEDs work except for the PR-8210 LED which I soldered on backward, then ripped up one of the pads trying to remove it. DOH! I haven't tried "animating" the LEDs yet but the fact that they all work suggests that the LED driver chip we chose is working properly.

USB wiring problem fixed! "Hello world" program works!

Indeed the TX and RX lines were backwards on the Dexter board so after performing a manual swap of those two lines, the Dexter board is now sending out to the serial port just fine. Here's a simple "hello world" program I wrote working correctly.

Looks like usb chip may be miswired

Looks like there may be a problem with the FTDI USB chip's "wiring". I was having trouble getting a simple "hello world" program running so I dug deeper and found this page which clearly shows that the TX/RX pins on the AVR should be opposite of the TX/RX pins on the FT232RL. I think I have this backwards. I will consult with Warren and Neil for the best way to fix this. It could be as simple as soldering two wires from the via's near the FTDI chip to the AVR's pins and then cutting two traces but we must proceed cautiously before performing surgery.

All rev2 prototype Dexter boards are sold

I neglected to mention this earlier, but all of the rev2 prototypes are sold. Thanks to all buyers who helped move this project forward!

Almost finished!

This board is complete except for LEDs and JTAG pins. I am going to hold off on soldering on all of the LEDs until I can test to see if the LED driver is actually going to work, hehe. Here's what I've got.

Made more soldering progress

I've got most (all?) of the capacitors and resistors soldered on. I want to see if the AVR works before I go any further.

Dexter USB chip works!!

I went ahead and bought a through-hole 4.7uF cap to replace the surface mount one I lost this morning. The soldering is a total hack job but the good news is I just plugged in the dexter board to my Windows 7 box and it not only detected the USB chip correctly but also was able to auto install the drivers! This is a very good sign! Once I finish the soldering I can hopefully see the coveted greeting from the AVR.

Shaun Wood's Dexter board

Shaun assembled his prototype before I did! It looks great.

Did some more soldering, lost C15

I did some more soldering this morning and got all of the 0.1uF caps installed. I just have a few caps left to solder before I move on to resistors. Unfortunately, as I was trying to get C15 out of its plastic housing I dropped it on the floor and can't find it which makes me very sad. Hopefully I can find a local place that sells these things.

A new forum for rev 2 prototype discussion

I've made a new forum to discuss the rev 2 prototype for those who have purchased boards. You can find it at this link. This is so that we can consolidate the discussion in one place. I will be putting all the info I have about assembling and using the rev 2 board there, although much of what I put there will probably link back to this blog :)

If you bought a rev 2 board and do not have access, you may need to create an account on the daphne message board and then tell me what your account is.

LED direction / orientation

Here's a picture showing the correct way to orient the LEDs when soldering.
It also shows the worlds worst soldering job by yours truly. I really hope to get better as I go along :)

UPDATE : I've added part of the datasheet that shows which side is 'pad' 1 and which side is 2.

Started soldering, the LED works!

Heather helped me solder on a few surface mount parts including a bunch of 0.1uF caps and the power LED. As you can see from the picture, it's not easy to be precise! But it should work fine anyway.

Here's where the parts go on the board

Here's a picture showing where all of the parts go on the board for those who ordered a board and now need to solder on parts.

Apologies for this super high res picture. Most of the resistors and caps have super small text. If I figure out a way to resize the text on everything without having to redo each individual component, I will release a smaller pic.

Direct link to pic: here.

23 Jan 2012 UPDATE : the direct link has changed as I have added some more labels that were missing and also made a note not to install C26.

Digikey parts should arrive today

The parts that I ordered from Digikey for my prototype should arrive today. I will probably post some pictures. Hopefully soldering will begin soon!

I will be shipping out at least two (and hopefully three) boards today.

6 boards sold, 2 more spoken for, 1 left

I had 10 prototypes made.
I am keeping one for myself.
I've sold six of them already.
Two more are spoken for and I am waiting for payment.
One remains and I am currently contacting people on my list in order to see if they are interested.

It's good to see that the community is helping to pay for the cost of making these expensive prototypes! Now we can move forward!

here's the parts list!

Here is a google spreadsheet showing all of the parts needed for the dexter PCB assembly.

I have also used this to create a Digikey Bill of Materials but digikey does not seem to differentiate between allowing read access and edit access (good design, digikey!) so this probably isn't something I can mass publish. I've also attempted to create a "kit" but as of now it hasn't shown up yet even though I have placed my order. If anyone with digikey experience knows how I can easily dispense a full list to people publicly, let me know. In the mean-time, you can import the google spreadsheet into digikey and create your own BOM which will allow you to remove parts you already have or don't need.

NOTE: If you don't have an AVR programmer (which most of you probably don't), you will also need to get this.

better pic of the dexter board

Here is a better pic of the board. I used my flatbed scanner so it will be a little out of focus.

Limited quantity Prototype Dexter boards have begun shipping

Today I shipped out some boards and tomorrow I plan to ship out more.

In deciding whom should receive boards, I have gone based on timestamp of those who have responded to me and expressed interest (first come first serve basis).

These are the people I am holding boards for that I have not talked to recently. So if you see your name here, I've either emailed you or sent you a PM on the d-l-p.com message broad. I want to know if you still are interested.

Gamer4Life
Tony M. Victorino
Barclay66

They're here! They look awesome!

can't believe I was gonna try to hand solder those SMT's! They are so small!

Boards will arrive tomorrow

According to ups.com:

Scheduled Delivery:
Wednesday, 01/11/2012, By End of Day

I will be sure to post pictures as soon as I can. so excited!

Boards have shipped from manufacturer to me!

I just got word that the rev 2 boards have shipped from the manufacturer to me via UPS ground (they are one state over so it shouldn't take too long). Once I verify that the SMT components are placed correctly, I will accept orders and ship them out to people. Price will be $90 + shipping and boards will be otherwise untested.

Got an update from the manufacturer

I emailed the manufacturer asking for an update (and hopefully some pics just so we can drool over them). Here's what I heard back:

update #1:
"Yeah we sure do have both parts and pcbs. This job is in my hands right now and will be getting moved to the production floor before I leave today."

update #2:
"Hello Matt,
We will move your order into production and your ship date is 1/16/2012."

No pics for now.