Pages: 1 [2] 3 4 ... 32   Go Down
Author Topic: ATMEL Mega1284P evaluation board avalible  (Read 60054 times)
0 Members and 1 Guest are viewing this topic.
nr Bundaberg, Australia
Offline Offline
Tesla Member
***
Karma: 121
Posts: 8461
Scattered showers my arse -- Noah, 2348BC.
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Just looking at the extra IO header, the rows aren't .1" spaced.

______
Rob
Logged

Rob Gray aka the GRAYnomad www.robgray.com

Left Coast, CA (USA)
Offline Offline
Brattain Member
*****
Karma: 332
Posts: 16568
Measurement changes behavior
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Wow, this is like watching a baby being born, only not as wet.  smiley-wink

Lefty
Logged

Global Moderator
Boston area, metrowest
Offline Offline
Brattain Member
*****
Karma: 446
Posts: 23872
Author of "Arduino for Teens". Available for Design & Build services. Now with Unlimited Eagle board sizes!
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Okay, next pass is ready.

5.5/2.1mm power jack.
Mini USB-B for Serial.
Crystal/capacitors for clock generation.
Full Shield compatibility (standard complement of Arduino pins).
RS232 for Serial1 with 4-pin header (Rx1,Tx1, Gnd, 4th is open). Rx/Tx jumpers to disconnect from driver if need Digital I/O or INT0, INT1.
INT2 available at D6.
Jumpers to select between A4/A5 and SCL/SDA at analog shield header.
Two pins added to analog shield header for A6, A7.
New 8 pin header for PC0-7 (includes SDA/SCL, even if jumpered to A4/A5).
(hmm, looks like I lost  an I/O pin for PD7 along the way)
SD MMC push-push with dedicated SPI SS line not available else where on the card. Ladyada style design with Write Protect, Card Detect signals.
Seperate 3.3V regulator for SD card.
FTDI FT232RL USB chip with 3.3V to shield.
ICSP header, allows BIT Bang programmig with FT232RL X3 header.
10 pin JTAG header.
Power LED, "L" (D13) LED, Serial Rx/Tx LEDs (not on Serial1).
No onboard reset - connect externally if needed (at shield pins, at ICSP, or at JTAG)
(tho it appears there is plenty of room to add one, guess one pass to put pads in for it).

My only concern is the USB connector - any one know which library part to use that will let what appear to be the shield pads get connected to ground in Eagle?
Here's  close up of what I have now.

« Last Edit: May 15, 2011, 01:56:54 am by CrossRoads » Logged

Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Smithfield, Rhode Island
Offline Offline
God Member
*****
Karma: 2
Posts: 843
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Is there a core available for the 1284P family?  (isn't it just a big 644?)

Do you picture this core having built-in support for the gadgets?

The cores at http://www.avr-developers.com will work on Bob's board, as will the bootloader.

They would work on the thing from Atmel as well. The only thing that makes an Arduino an Arduino is the bootloader.
Logged

Smithfield, Rhode Island
Offline Offline
God Member
*****
Karma: 2
Posts: 843
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Why DIP vs SMD?

Another advantage of DIP is that you could make it available as a kit. If the crystal is in a socket then the user can select the speed they like, although i don't know if a crystal in a socket works as well as a soldered crystal.

Logged

Smithfield, Rhode Island
Offline Offline
God Member
*****
Karma: 2
Posts: 843
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I'd ditch the DB9 and use a header. You can get IDC DB connectors that use ribbon cable so they still look neet and can easily be mounted remotely, makes fitting the board into an enclosure easier and you can swap from male to female without desoldering a connector.


Thats a cool idea!
Logged

Global Moderator
Dallas
Offline Offline
Shannon Member
*****
Karma: 178
Posts: 12293
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
The cores at http://www.avr-developers.com will work on Bob's board, as will the bootloader.

I agree.

Quote
They would work on the thing from Atmel as well.

Nope.  millis, micros, delay, and delayMicroseconds will not work correctly at 11.0592 MHz.  Which is why I asked if clock speed was the only issue.
Logged

nr Bundaberg, Australia
Offline Offline
Tesla Member
***
Karma: 121
Posts: 8461
Scattered showers my arse -- Noah, 2348BC.
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

RE the RS232 connector.

As soon as you have to solder up wires to headers and connectors it looks like a dog's breakfast. Consider the following

a) serial on a DB9 only needs 3 signals on pins 2, 3 and 5.
b) The smallest IDC connector you can get (AFIAK) is 6-way.
c) You have room for a 2x3 header (same as the ISP header).

So I would add the 2x3 header so there is a quick and neat solution to wiring up serial with IDC connectors.

THEN

If there is room. Add a 2x2 header for jumpers so the polarity can be easily swapped.

All in all this allows two Arduinos to be neatly connected with no crappy soldered wires.

______
Rob
Logged

Rob Gray aka the GRAYnomad www.robgray.com

North Yorkshire, UK
Offline Offline
Faraday Member
**
Karma: 104
Posts: 5531
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I'd suggest MicroSD instead of SD - most people have MicroSD cards now and if not then they're not expensive.
Also, due to the size of the DIP chip, you can fit parts underneath it (not that I can see much on your board that could go under it).

Quote
So I would add the 2x3 header so there is a quick and neat solution to wiring up serial with IDC connectors.
Could get confusing as 2x3 is the same as the ICSP - I suppose good silkscreening solves this problem.
Logged

Global Moderator
Boston area, metrowest
Offline Offline
Brattain Member
*****
Karma: 446
Posts: 23872
Author of "Arduino for Teens". Available for Design & Build services. Now with Unlimited Eagle board sizes!
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Looks like my ISP is acting up today, so the files are not viewable. Time for a phone call to see what's going on.

> I'll check out RS232 cable headers, see what exists.
> Crystals work in sockets, es evidenced by the wirewap boards I have built up.
> 16/20 MHz - 3-pin socket strip would let one put in either frequency.
> There are some parts under the 1284, socket strip intended to be used now to plug in the processor.

> SD/MicroSD - maybe I can put both footprints in the same spot so one or the other can be installed.

ISP seems to be back up?
« Last Edit: May 15, 2011, 11:13:13 am by CrossRoads » Logged

Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Global Moderator
Boston area, metrowest
Offline Offline
Brattain Member
*****
Karma: 446
Posts: 23872
Author of "Arduino for Teens". Available for Design & Build services. Now with Unlimited Eagle board sizes!
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Ok, looks like the sparkfun microSD footprint will fit nicely under the regular SD footprint.  Most signal names to connect in parallel are obvious.

The SD design brings the card detect (CD) and write protect (WP) signals out.

Any ideas if CD1 and CD2 are the same features on the microSD?
And what does RSV do?

« Last Edit: May 15, 2011, 11:36:34 am by CrossRoads » Logged

Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Left Coast, CA (USA)
Offline Offline
Brattain Member
*****
Karma: 332
Posts: 16568
Measurement changes behavior
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

If it was my design I would throw out all the auto-voltage switching components and instead use a simple 3 pin SIP and a jumper clip. This would save on component costs and board space avalible for more useful stuff. I never liked the Arduino auto-voltage circuit, looks like a solution looking for a problem.

Lefty

Logged

Smithfield, Rhode Island
Offline Offline
God Member
*****
Karma: 2
Posts: 843
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Nope.  millis, micros, delay, and delayMicroseconds will not work correctly at 11.0592 MHz.  Which is why I asked if clock speed was the only issue.


What happens if the F_CPU is set to that frequency?
Logged

Global Moderator
Dallas
Offline Offline
Shannon Member
*****
Karma: 178
Posts: 12293
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
millis, micros ... will not work correctly at 11.0592 MHz ... What happens if the F_CPU is set to that frequency?

The rule for the clock frequency because of the way the code is written...
http://arduino.cc/forum/index.php/topic,59263.msg427808.html#msg427808

An example of what happens when the rule is not followed...
http://arduino.cc/forum/index.php/topic,59263.msg426611.html#msg426611
Logged

Smithfield, Rhode Island
Offline Offline
God Member
*****
Karma: 2
Posts: 843
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Okay so you're saying the crystal freq has to be a power of 2? But there are other boards that do not follow this rule. These boards claim Arduino compatibility and work with Arduino cores from avr-developers.com. Here is a list:


arduino_amber128.name=Arduino-Amber 128 14.7456 Mhz
arduino_amber128.build.f_cpu=14745600L


arduino_OrangutanSVP1284.name=Arduino-Orangutan SVP-1284
arduino_OrangutanSVP1284.build.f_cpu=20000000L


arduino_gator.name=Arduino-Rugged Circuits Gator Board
arduino_gator.build.f_cpu=20000000L


arduino_bahbots1284p.name=Arduino-BahBots 1284p
arduino_bahbots1284p.build.f_cpu=18432000L

Logged

Pages: 1 [2] 3 4 ... 32   Go Up
Jump to: