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Topic: Small server/logger/gateway based on ATMEGA1284 (Read 10 times) previous topic - next topic

Stewie

#15
Jul 11, 2013, 07:04 am Last Edit: Jul 11, 2013, 07:42 am by Stewie Reason: 1
If you get your own PCB's made when the design files are available, you can just fit the components you want, bridging out the RS485 driver will let you still use the serial channel, but at logic-levels.

When I release the files, the PCB artwork will be in a zipfile, just email it to seedstudio, pay the low fee and a few weeks later your very own batch of 10 boards will arrive.

There are refinements I want to make for a next version, perhaps a LED on the board and a reset button. I really want to keep to 1206 resistor/cap packages as for home assembly they are quite manageable, and to keep away from the tiny sm footprints as I just cant work with them. I did have to resort to three 0803 components, the xtal caps and a ferrite bead.
Perhaps some solder bridges for power and 2nd serial options. I'm trying things to see what I can fit.
At this point, I dont have any way to sell these, or even have an idea if people would want them. I made these with my requirements in mind, ie the RS485 port is not a common requirement. I can probably make it optional (bypass the chip) so in that regard its more generally useable.
So I'll just keep on with the testing and trying to fit any modifications I can think of (or are suggested)

I was lucky enough to be one of the Goldilocks backers, I cant wait to get mine.
Its in a completely different class from my effort. It is a very well engineered board and a huge amount of effort and thought has gone into it to make it one of the most 'serious' Arduino's I have come across, suitable for complex and diverse applications, even using the two CPU's for independent programs and communicating between them.

I just thought of the bits I wanted, crammed them into a small space and figured its worth a try... If its a dud then its not the end of the world. If it all works then happy me.
I just like making stuff  :)

MarsWarrior


If you get your own PCB's made when the design files are available, you can just fit the components you want, bridging out the RS485 driver will let you still use the serial channel, but at logic-levels.

When I release the files, the PCB artwork will be in a zipfile, just email it to seedstudio, pay the low fee and a few weeks later your very own batch of 10 boards will arrive.

There are refinements I want to make for a next version, perhaps a LED on the board and a reset button. I really want to keep to 1206 resistor/cap packages as for home assembly they are quite manageable, and to keep away from the tiny sm footprints as I just cant work with them. I did have to resort to three 0803 components, the xtal caps and a ferrite bead.
Perhaps some solder bridges for power and 2nd serial options. I'm trying things to see what I can fit.
At this point, I dont have any way to sell these, or even have an idea if people would want them. I made these with my requirements in mind, ie the RS485 port is not a common requirement. I can probably make it optional (bypass the chip) so in that regard its more generally useable.
So I'll just keep on with the testing and trying to fit any modifications I can think of (or are suggested)


You should be putting your own requirements on top of course. I guess you could make modifications for the rest of this year by implementing wishes from other ppl. On the other hand, I don't see so many other ppl showing interest =( It seems not many run out of the 328P RAM/ROM space, and thus requiering something like a 1284P.

Looking at my own personal wishes: running the board on 3.3V is currently the most important one. A better RTC like the DS323x would be nice (but more expensive, and much larger size, ie probably difficult to fit) and some extra I2C and SPI headers for easily connecting sensors also.

Quote

I was lucky enough to be one of the Goldilocks backers, I cant wait to get mine.
Its in a completely different class from my effort. It is a very well engineered board and a huge amount of effort and thought has gone into it to make it one of the most 'serious' Arduino's I have come across, suitable for complex and diverse applications, even using the two CPU's for independent programs and communicating between them.


The Goldilocks board is indeed a well thought, high quality 4-layer board, but no pluggable LAN and only a 6-pin extension header for RF cards (couldn't get 8-pins to fit due to the Arduino compatible holes). All the Freetronics boards have the prototyping area. I guess if that wasn't necessary the LAN/RF headers could have been added.

Because of this your board fits my needs much more... Next to that, I have some breadboard designs that are running for a few years without any problems, so I don't seem to be in need of high quality, factory grade stuff  XD. That these breadboard designs do work so nicely is a bit of a surprise (to me), as I'm not a hardware designer :smiley-red:

Pricing will probably also something different. 10 PCB boards for around €10-€15, ie €1.50 / board. Then €6 for the 1284P, €2 for the NRF24, so I guess the total board (without SD/LAN shields) won't be more than €15... Priceless  $)

Quote

I just thought of the bits I wanted, crammed them into a small space and figured its worth a try... If its a dud then its not the end of the world. If it all works then happy me.
I just like making stuff  :)


The 1284P, as I'm always running out of RAM, certainly combined with LAN, is the key factor for me. I'm also looking for a board that could become my standard board to use for several prototypes (and thus re-use of software). Next, I like the formfactor. It fits a standard, cheap 1591M Hammond case nicely. Even if you would extend the board to the 49.5x49.5mm limit as Hammond has 85x56x21mm, 85x56x35mm small enclosures (inside is just over 51mm, so a perfect fit) and a bit bigger the 112x62x27mm and 120x65x36mm ones. The larger boxes can even fit two of these boards, giving you dual-core 1284P power!

Stewie

for enclosure sizes, dont forget that the radio either sticks up, or behind.
I'm looking at both options, I'm tending towards a footprint that allows a right-angle connector on the rear of the PCB so the radio sticks-up. This allows a vertical radio, or if no Wiznet module fitted then a vertical connector so the radio is above and parallel to the main PCB.
Not sure if some kind of screening would be required between the micro and the transmitter but with such close proximity its certainly worth considering.
-The above is with the cheap ebay nRF module footprint (2x4 pin)
I'm experimenting with other PCB options. Solder bridges if no RS485 fitted seems OK, reset button is OK, LED should be fine but not done yet and still considering power options.

MarsWarrior

Martins Funky v2 (http://harizanov.com/wiki/wiki-home/funky-sensor-v2/) has the Atmega 32u4 and a Hope RFM12B sandwitched together, so I guess not much of a problem having them very close together.

Stewie

It probably will be OK.
One of my boards is a ATtiny861 with a RFM12, at http://byremote.blogspot.com.au/2013/03/rfm12-mini-nodes-tiny861.html , is quite similar but slightly larger, its never been a problem for me. The RFM12 works at 433Mhz. I wondered if 2.4Ghz might be more of a problem. It comes down to try and see I suppose.
If your interested, the design files for the atTiny board are on AVRfreaks.. http://www.avrfreaks.net/index.php?module=Freaks%20Academy&func=viewItem&item_type=project&item_id=3848

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