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Topic: Two chip sanity check (Read 7245 times) previous topic - next topic

Njay

I wrote these 2 small articles specifically on doing several things at the same time:

How to do several things at the same time

More on doing several things at the same time

cyclegadget

@CrossRoads,

If your going to do it, do it BIG! Dual '1284s would totally rock! I probably would never get full use out of it but, it sure would be a neat little toy!

CrossRoads

Okay, I'll order some boards tonight. Was thinking about how to make a shield type board to go with it, what to do with all the pins that are there, which to bring up or to leave holes for, etc.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Texy


Got it designed, still thinking about about other options before I plop down $25 for boards...
Take your pick, dual '328s or dual '1284s

Hey crossroads, where do you order your pcbs from?
Texy

CrossRoads

My 2 orders have been with iteadstudio. Am waiting for mini-uino's to show up, status on 50-lot of 1.3" x 1.3" PCBs is "departure from outward office of exchange" on 9/4.
Prior order for Bobuino's took a while too.
http://iteadstudio.com/store/index.php?main_page=product_info&cPath=19_20&products_id=175&zenid=edplpd8kf14ntqn128uncg0bd6
and
http://iteadstudio.com/store/index.php?main_page=product_info&cPath=19_20&products_id=173

seeedstudio offers similar
http://www.seeedstudio.com/depot/fusion-pcb-service-p-835.html?cPath=185
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

EmilyJane

I guess this is sort of on topic, certainly goes with the subject anyway.  :) Back at the beginning of time when microprocessors had 1 MHz clocks and program and data storage was external to the processor, using more than one CPU in a system sometimes was vital rather than just an interesting thing to do. For example, in a data acquisition and processing system, to get the throughput necessary for success, one could have one CPU controlling data acquisition and buffering and another CPU handling computations and HMI. Since early microprocessors had external address and data busses and memory some interesting things were possible.

If the CPU clock was two phase, you could operate the CPUs off of opposite phases and therefore share the same physical program and data storage. Since many times there were functions that were common to both subsystems, sharing the program storage was an economical thing to do, as EPROMs were relatively expensive then. Data storage sharing was particularly compelling because it eliminated the interprocessor communication that would have slowed things down otherwise. A system of semaphores in shared R/W memory kept things synchronized and since the CPUs were on oposite phases of the clock, there was never any interference. Completely separate areas of program and data could also be maintained if that was desired.

Nowadays we just throw another $3 microcontroller at the problem. :D

CrossRoads

Well,  maybe a little more - $5.82 at mouser currently  :smiley-mr-green:
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

EmilyJane

Hah, I used to pay that much for 128 bytes of RAM.  :D

CrossRoads

Yeah, prices sure have dropped.
And now a 512K x 8 SRAM is $4.70
http://www.mouser.com/ProductDetail/ISSI/IS61WV5128BLL-10TLI/?qs=sGAEpiMZZMs6Aik9Fp479htyRPPcVL%252bzv89zHNw4tYc%3d
Maybe I'll make a 1M x 16 SRAM for capturing  24 second sound samples at CD quality.
4 chips, 3 8-bit counter chips, a couple of transceiver to mux the 2 bytes & store to  SD card, 16 BIT DAC to play it back for a sound check ...
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

CrossRoads

Didn't get to ordering boards yet- realized I hadn't done the gerbers & checked them out yet. Couple more days...
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Texy


My 2 orders have been with iteadstudio. Am waiting for mini-uino's to show up, status on 50-lot of 1.3" x 1.3" PCBs is "departure from outward office of exchange" on 9/4.
Prior order for Bobuino's took a while too.
http://iteadstudio.com/store/index.php?main_page=product_info&cPath=19_20&products_id=175&zenid=edplpd8kf14ntqn128uncg0bd6
and
http://iteadstudio.com/store/index.php?main_page=product_info&cPath=19_20&products_id=173

seeedstudio offers similar
http://www.seeedstudio.com/depot/fusion-pcb-service-p-835.html?cPath=185

10cm x 10cm x 10 pieces, only $24.90 (plus shipping) - WOW.
They also supply an Eagle to Gerber conversion program (I have only ever used Eagle before).

Texy

CrossRoads

Eagle exports Gerbers directly. Downloads itead's 'rules' file, it will provide the setup files needed so you can select in eagle files:export and have the file outputs needed created and check what you will be getting,
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Texy

#27
Sep 15, 2011, 02:02 pm Last Edit: Sep 15, 2011, 02:11 pm by Texy Reason: 1
Many thanks CR - I will download that and give it a go, once I,ve designed my board.
Do I need both the .cam and .dru files?
How long did it take you take get your boards, once ordered?
(I know we will in different countries, but it may just give a ball park figure).

Texy

JChristensen


Back at the beginning of time...


Good stuff!  6800?  8080?  6502?

JChristensen


My 2 orders have been with iteadstudio.


Might have to give them a try, gonna be hard to beat their $/in2 rate. @CrossRoads, what sort of turnaround time do you see from them?

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