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by lrvick
Mon Jul 16, 2012 8:46 pm
Forum: Python
Topic: Python driving 44780 LCD
Replies: 101
Views: 45928

Re: Python driving 44870 LCD

Hey, after i tested the date and so on its very easy to write something to the Raspi. Now i got a ver simple Problem, when i write: lcd.message("example") then the lcd show me something like this: mple so it cuts the first characters, the reason for me was to write this: lcd.message(" example") the...
by lrvick
Sat Jul 14, 2012 11:43 pm
Forum: Python
Topic: Python driving 44780 LCD
Replies: 101
Views: 45928

Re: Python driving 44870 LCD

Hey, i get it running and its fine. I used the class ;-) Thx lrvick. But now i want to write the date and time to my LCD, but i dont know how i can do that. Can anyone help me pls? Thx Tailer Here is a very simple clock using my class: from hd44780 import HD44780 from datetime import datetime from ...
by lrvick
Sat Jul 14, 2012 11:10 pm
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 92148

Re: USB Port Current Boost

Warranties are just silly on a $35 device anyway. Not even worth my time to fill out the paperwork and pack it up. I'd just order another one ^_^ What?? Where is the imperative on the part of a manufacturer / supplier to improve their product or service if you remove that particular feedback loop? ...
by lrvick
Sat Jul 14, 2012 7:27 pm
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 92148

Re: USB Port Current Boost

But do note that soldering resistors to the polyfuses will void your warranty, and may also overheat the polyfuses themselves Yeah.... I just grabbed 2 irons and removed the polyfuses so they were not in the way of making my resistors nice and flush. Warranties are just silly on a $35 device anyway...
by lrvick
Sat Jul 14, 2012 7:22 pm
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 92148

Re: USB Port Current Boost

Lob0426 wrote:That is good news. Did you plug and unplug to see if your RasPi was resetting?

I just checked my USB polyfuses F1 is 7 ohms :shock: , F2 is 5 ohms and F3 is .001.
So 1 ohm is a lot better than that. :lol:
I did. Hot-plugging is working as expected for all devices. =D
by lrvick
Sat Jul 14, 2012 6:31 am
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 92148

Re: USB Port Current Boost

Simply take two 1 Ohm quarter watt or eight watt resistors. simply solder a resistor over both sides of the green polyfuse, (F1) . That is one wire on either side of the same polyfuse. Repeat for the second polyfuse (F2). That is All! Went ahead and tried this verbatim. Wireless adapters work in ei...
by lrvick
Tue Jul 10, 2012 1:23 pm
Forum: Python
Topic: Python driving 44780 LCD
Replies: 101
Views: 45928

Re: Python driving 44870 LCD

In my case I have a 3.3v version of the Hd33780 LCD which I wired up like so: http://i.imgur.com/OGcb2.jpg (excuse the terrible soldering job, I only had a way over-powered iron with a fat tip handy) To drive it I forked texys code and made it into a class that is a fair amount faster, however it is...
by lrvick
Tue Jul 10, 2012 11:52 am
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 92148

Re: USB Port Current Boost

We keep having the discussion of the issues and the possible fixes. Now we have one. apparently, viable cure for the USB problems. What we do not have is any schematics of the possible circuits. @Irvick: (+5v) -- (0.5ohm resistor) -- (+ 220uF cap -) -- (wire) -- (USB V+ pins) ?...(-5v(TP2?)) -- (US...
by lrvick
Mon Jul 09, 2012 9:32 pm
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 92148

Re: USB Port Current Boost

Note that if you use a diode (of any kind) in series with the power to the USB device, you end up with a similar voltage drop that you were trying to remove by bypassing the polyfuse (a few hundred millivolts). The problem is actually simple to understand; A good capacitor will , at the moment you ...
by lrvick
Mon Jul 09, 2012 8:25 pm
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 92148

Re: USB Port Current Boost

I finally went a little crazy and spent several hours working on this problem with multimeters, digital bench power supplies with current meters, fully isolating usb power, monitoring drops and resets... I have what I now appears to be a solution. The bottom USB port issues were resolved for my by s...
by lrvick
Sat Jul 07, 2012 12:01 pm
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 92148

Re: USB Port Current Boost

For those having problems after fitting the 'pi-pass' it might be worth trying adding a second wire to bypass the pcb tracks of the ground connection. (When increasing the current capability you need to consider both the supply and the ground Impedances.) Additional capacitance as mentioned above a...
by lrvick
Sat Jul 07, 2012 11:46 am
Forum: Python
Topic: Python driving 44780 LCD
Replies: 101
Views: 45928

Re: Python driving 44870 LCD

Hi, with thanks to information in this thread : http://www.raspberrypi.org/phpBB3/viewtopic.php?f=64&t=4934 I have been able to get a LCD module to display messages using python directly from the GPIO The code is not very clever, and also not very fast - I,m sure that some of you python experts can...
by lrvick
Thu Jul 05, 2012 1:08 pm
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 92148

Re: USB Port Current Boost

Has anyone bridged F1 & F2 and replaced the standard 47 microFarat for a 220 microFarat yet? This way both USB ports may stay oparational... :) I just tried this exactly. 47uF -> 220uF and bypassed F1 & F2. The result however was not any better than the non-cap pipass. Top port could use higher pow...
by lrvick
Thu Jul 05, 2012 12:17 pm
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 92148

Re: USB Port Current Boost

On further testing I found that even when I am only supplying the extra power to only the bottom port, it still refuses to acknowledge the USB-N10. I did find however that the bottom port however does continue to acknowledge other lower-powered devices. When I supply the extra power to the top port,...
by lrvick
Wed Jul 04, 2012 3:52 pm
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 92148

Re: USB Port Current Boost

So here is where I am at: 1. Tried USB-N10 wifi dongle, failed to enumerate the device every time. Not enough power, clearly. 2. Did "pi-pass". Bottom USB port stopped working, but the top port could support the dongle only if the device was started with it. (no hotplug) 3. Fearing I damaged my boar...
by lrvick
Wed Jun 27, 2012 10:57 pm
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 92148

Re: USB Port Current Boost

Hmm. Interesting that others are doing the same mod and not having the bottom port die. I am very positive there is no bridging

What gauge wire are you guys using? Perhaps mine is too thick.

Can one that has both ports working snap a photo perhaps?
by lrvick
Wed Jun 27, 2012 8:24 am
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 92148

Re: USB Port Current Boost

I too did the pi-pass mod. I was then able to run higher powered devices like my USB-N10 off the top port, but as mentioned here by others, the bottom port became unresponsive. Also the USB-N10 must of been plugged in at boot for it to work. I can confirm that hot plugging a USB-N10 with the pipass ...
by lrvick
Wed Jun 20, 2012 4:48 pm
Forum: Other projects
Topic: Hookup help for cheap 3.3v 16x2
Replies: 3
Views: 2347

Hookup help for cheap 3.3v 16x2

So I have one of these: http://nkcelectronics.webstorepowered.com/16x2-Module-white-Backlight-Arduino/dp/B007LO3Y9W It is 3.3v logic so in theory I feel like I should be able to hook this directly to the pi GPIO pins but I am unsure what pins to use. Should just be a standard 44780 pinout on the boa...

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