Printer just doesn't print?

[Eng Sui Kee]

Hello! 

Not sure if this is still remotely active but thought I'd give it a shot anyway, I'm fairly new to arduino but really want to try to make this printer work. 

I've build the printer and the right LEDs turn on when I send a message (downloading to ready) but nothing happens when I push the button. The ready LED just goes off and the printer doesn't even budge, it sounded like it was going to print once but nothing happened. The LED on the printer does seem to flash a lot faster when I push the button but that's about it. 

The printer has worked when I've had it directly connected to the arduino before, so I'm not sure what could be the issue here, any help is greatly appreciated!

Cheers

Suikee

[Eng Sui Kee]

the debug output: 

75282: Attempting to connect to printer.exciting.io

75360: Waiting for data

75360: Waiting for data

75361: Waiting for data

75370: Waiting for data

75396: Waiting for data

75422: Waiting for data

75448: Waiting for data

75474: Waiting for data

75539: Content length: 5441

76268: Waiting for data

76269: Waiting for data

76269: Waiting for data

76279: Waiting for data

77475: Waiting for data

77476: Server disconnected

77503: Bytes: 5441

77504: Duration: 2235

[James Adam]

Hi Suikee,

That debug output would seem to confirm that the data download is working (the number of bytes matches the content length the server reports), so the first thing I'd investigate is the electronics. Assuming that you're confident you've connected the printer data wires the right way round (I often confuse the TX and RX), I wonder if your printer is getting enough power? How many voltes & amps is the power supply you're using?

--

James

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[Eng Sui Kee]

Hi James

Thanks for getting back to me so quickly! I'm pretty confident I connected it right, will check again when I'm home. 

It's supplied with 5V 2A. Could it possibly be because I'm using higher ohm resistors? I didn't think it would make such a big impact but I'm going to try getting my hands on some 560 ohms ones today and try again tonight. 

Cheers 

Suikee

[James Adam]

Hmm; that power supply should be fine, certainly in terms of current. I can't imagine the resistors would make a difference, at least not in the sample circuit we provide, as they aren't even in line with the printer wiring.

If you're connecting everything using a breadboard, it could be worth using a multimeter to verify that each connection between the Arduino and the printer through the breadboard is unbroken.

The one strange thing is the printer light flashing faster when you press the button. I'm pretty sure I haven't seen that before.

When you connected the printer directly to the Arduino, where were you connecting the printer power supply?

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James

[Eng Sui Kee]

I've tested it by connecting the printer directly to the power supply and it's printing! But only the top bits or less of anything I've sent. 

[James Adam]

Can you send a picture with some examples? This sometimes happens if the paper sticks to the print element, which might indicate the darkness needs to be calibrated.

– James

[Eng Sui Kee]

I've read somewhere that it might be due to needing a higher voltage but the test print of the printer's character code table worked fine so now that it's directly connected, that shouldn't be the problem :/ 

[James Adam]

To me that looks like fairly classic paper-sticking, which has two typical resolutions

1) Reduce the darkness setting (you should see this on your 'my printer' page)

2) Try a different brand of paper

It's not unusual for the test page to work fine and still see these problems; the test pages print in "text" mode which is generally lighter and uses less element heat than "bitmap" mode, which is what gets sent from the server here (in order to support arbitrary fonts and images).

Hope that helps!

--

James

[Eng Sui Kee]

Ahh I see! Reducing the darkness setting doesn't seem to help but I'll try again when I get more paper. Thanks! 

[Eng Sui Kee]

Hello again! 

I've got new paper and it works at a range of 120-140 for darkness which is fine, I guess I still haven't managed to get the ideal paper for it but this'll work for now. 

Thanks for all the help!! 

[James Adam]

Glad to hear you're making progress :)

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James