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Author Topic: [Solved] Problems accessing parallel SRAM  (Read 7661 times)
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I have a charger for a Motorola phone that has a power output of 5V-500mA: I cut its connector and made a built-by-me adaptor to use with breadboards :-)
It works very well: I've already used it in a replica of the Hackvision miniconsole.
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That sounds like plenty then. The other thing you might consider is 0.1uF caps between the VCC & GND pins of the chips.
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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.
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Code:
    shiftIn(load_data, clock_pin, value);

is wrong. It doesn't store the value received anywhere. Strangely, I can't find shiftIn in the reference documentation, but the function definition is
 
Code:
uint8_t shiftIn(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder)

so I guess you want value= shiftIn(load_data, clock_pin, LSBFIRST);  (or MSBFIRST)

Debugging with an LED is a good idea. Start off by making sure the right addresses are getting to the RAM.
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@CrossRoads:
I've already put some 0.1 uF cap.s around, on every chip Vcc.

@stimmer:
Is was to find ShiftIn for me too.
If you go into the References/Language, you find "ShiftOut". From it, at the end of its page, you'll find the link to ShiftIn:
http://arduino.cc/en/Reference/ShiftIn

Nevermind, I saw that I made a mistake. In fact, your sintax is correct, 'cause "value" must be replaced from bitorder. Thanks, maybe this is the good time!  smiley-lol
I'll try as soon as possible...
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SUPERB! It works!!!!  smiley-lol smiley-lol smiley-lol smiley-lol

3 days looking at the circuit thinking the worst things.... and it was s stupid function that I miswrote in my code!!!

Thnaks stimmer for having opened my blind eyes  smiley-kitty
Thanks CrossRoads for your suggestions, too, because with your suggestions I made a very much simplier circuit with 4 or 5 pins less than the original.
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I was thinking.... what about an article for the playground? If I'm right, there are no articles about reading/writing from parallel RAM, isn't it?

I think it could be interesting for someone else, don't you?
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Glad to help - hadn't looked into your syntax, didn't occur to me there might be something amiss. Nice catch there stimmer.

Playground article - sounds good. There was someone else earlier trying to come up with a dual access SRAM. Haven't heard anything on that one in a while.

Does this look familiar?


* dual_access_memory_ics_pg1.jpg (118.76 KB, 960x626 - viewed 40 times.)

* dual_access_memory_ics_pg2.jpg (67.92 KB, 960x530 - viewed 30 times.)
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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.
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Yes, it looks veery familiar because.... it was me that asked that smiley-lol smiley-lol
I had drawn my circuit using your old schematic too :-)

You are a force, my friend  smiley-lol smiley-lol
Thanks again for your support and for your patience.

This is the first step. Access to an SRAM with 1 Arduino. Now that I got the Master Degree in Chiponics ( smiley-mr-green ) I can start trying to access to the SRAM using an Arduino and a vanilla Atmega.

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Oh, that is too funny! I was looking in the old forum trying to find that thread. I don't think you had any code then.
Nice work - some of you guys are way better than me at putting that stuff in functions. My code tends to look like everything all written out.
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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.
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When I made that request I didn't have any code but I didn't have any idea on how chips works too  smiley-mr-green
I learnt about chips thanks to this forum and the datasheets of the chips I bought.

And, I'm sure, it's easy with theachers like you and stimmer  smiley-grin
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