Tapuino, the $20 C64 Tape Emulator

[spcbm]

Regarding the buzzer, I presume there is no polarity to respect.

Positive pin pointing to IC1, if you use passive buzzers the polarity is not important.

OK, thanks.
Just a couple of notes about the BOM if you allow me:

-About C1 capacitor : it would be better to write 47uF and not 47MF (someone could think Megafarad)
-About T1-T2-T3 transistors : it would be better to indicate them as 'PN2222' (TO-92 package) since the original '2N2222' come with a TO-18 package which would not fit in the Tapuino PCB.

Yes you are right, any NPN transitor with 500 mA or more Ic max will do the job

[penrods]

Hi,

My Tapuino displays nothing on the LCD screen when powered on (it has power)

I have tried adjusting the contrast pot on the back but no joy, although I notice that I can make out the pixels of the screen on the top row only.

I have tried two C64's incase not enough power but same result.

I have also double checked the wiring , e.g. GND goes to GND

Have tested the Arduino with a simple blink LED sketch and works as expected.

Upload of the Tapuino sketch reports done but provides the following - is this normal;



Sketch uses 28,338 bytes (92%) of program storage space. Maximum is 30,720 bytes.
Global variables use 1,728 bytes (84%) of dynamic memory, leaving 320 bytes for local variables. Maximum is 2,048 bytes.
Low memory available, stability problems may occur.

Here is the LCD I have
http://www.ebay.co.uk/itm/2009849711...%3AMEBIDX%3AIT

Here is the Arduino I have
http://www.ebay.co.uk/itm/1115285345...%3AMEBIDX%3AIT

Have read somewhere that it could be a timing issue

Any ideas?

It may be a duff LCD, if someone could please list the key presses I could attempt to load a TAP "blind" to prove that it's the LCD at fault?

Thanks
Lee

[spcbm]

Hi,

My Tapuino displays nothing on the LCD screen when powered on (it has power)

I have tried adjusting the contrast pot on the back but no joy, although I notice that I can make out the pixels of the screen on the top row only.

I have tried two C64's incase not enough power but same result.

I have also double checked the wiring , e.g. GND goes to GND

Have tested the Arduino with a simple blink LED sketch and works as expected.

Upload of the Tapuino sketch reports done but provides the following - is this normal;



Sketch uses 28,338 bytes (92%) of program storage space. Maximum is 30,720 bytes.
Global variables use 1,728 bytes (84%) of dynamic memory, leaving 320 bytes for local variables. Maximum is 2,048 bytes.
Low memory available, stability problems may occur.

Here is the LCD I have
http://www.ebay.co.uk/itm/2009849711...%3AMEBIDX%3AIT

Here is the Arduino I have
http://www.ebay.co.uk/itm/1115285345...%3AMEBIDX%3AIT

Have read somewhere that it could be a timing issue

Any ideas?

It may be a duff LCD, if someone could please list the key presses I could attempt to load a TAP "blind" to prove that it's the LCD at fault?

Thanks
Lee

It looks like a bad wiring with I2C, double check the soldering and cables, look for bridges on the SDA or SCL pads on PCB, or try to swap the two wires to LCD, not the power (+5V) or GND, just the SDA & SCL
IF you welded the I2C board, check the soldering.

You can test Tapuino with a +5V volts DC power.

When the LCD has no communication with Arduino, IIRC just the upper pixels appears.

Upload of the Tapuino sketch reports are OK, the memory usage is very high.

[Sven1973]

there is one other thing to check eventually.
i have one display which is set on another adress as told to me. the seller told one adress, on PCB is written the next and in real time it was just nothing of both...
same problem happened to derschatten, he used a programm for arduino to listen where the display is sitting, i did it by trial and error

thats the price for cheap hardware

[spcbm]

@penrods: I forgot to say that your Tapuino PCB was assembled and tested with my LCD, so the problem must be the adressing as Sven1973 says

I found this pages when I had a problem with LCDs:

http://www.instructables.com/id/1602...er-Addressing/
http://forum.arduino.cc/index.php?topic=158312.0

but in my case it was just the contrast pot.

[penrods]

Hi

Thanks for the replies,

I ran the I2C scanner which came back with an address of 0x27, which is the same address used in the code. I tried swapping SDA and SCL but no difference to output.

I've ordered another I2C interface and LCD, this time with them pre-soldered together, just incase my poor soldering is the issue!

Will update once received

Thanks again
Lee

[sweetlilmre]

If the i2c scanner picks it up can you try a hello world program for that lcd and see if it works? There is a very small possibility that the i2c chip is wired differently to the lcd pinouts which could be adjusted via the config file, but we would need a working sample first.

Edit: just checked, there is a sample program in the eBay description for your lcd/i2c.

[sweetlilmre]

Hmmm just checked out the sample code and it looks like the same code I based the current driver on! Additionally the pins seem to be configured in the same way.

See if you can run the code successfully and we can go from there. Sorry for limited comms I am on an island.

One last thing, just as a sanity check: are you sure the Nano is plugged into the board the correct way?

Sent from my SM-G900F using Tapatalk

[demolition]

Sorry for limited comms I am on an island.

If you're talking about Africa, then I'd qualify that as quite a big island.

[sweetlilmre]

Lol Zanzibar to be specific

-(e)