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by dentex
Wed Nov 30, 2016 2:28 pm
Forum: Off topic discussion
Topic: Links in signature.
Replies: 6
Views: 1836

Re: Links in signature.

Ok guys. Thanks for your replies. From what I understand, should be possible to add links in signatures (moreover, I'm not seeling anything). Since there are no clear rules against this practice, as a result I'm putting back again some links down there. I'll let you judge how much inappropriate they...
by dentex
Tue Nov 29, 2016 11:54 am
Forum: Off topic discussion
Topic: Links in signature.
Replies: 6
Views: 1836

Links in signature.

Hello. Some time ago I've been warned by a moderator to remove a couple of links that I had in my signature. Incidentally, nothing "commercial" or not appropriated, IMHO (some repo on GitHub, a RPi dashboard, etc). Anyway, I complied. A problem is that I see links in signatures everywhere: so, are t...
by dentex
Fri Nov 11, 2016 11:33 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Sainsmart 16x2 I2C lcd
Replies: 27
Views: 33335

Re: Sainsmart 16x2 I2C lcd

Thank you for your response! Unfortunately nothing has changed with my problem. [email protected]:~/lcd $ python lcd_print.py --init --debug -x test1 -y test2 ******************* Doing initialization... ******************* 1=>test1 2=>test2 ******************* And on LCD still one row with 16 rectangl...
by dentex
Fri Nov 11, 2016 8:04 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Sainsmart 16x2 I2C lcd
Replies: 27
Views: 33335

Re: Sainsmart 16x2 I2C lcd

Dear, [...] I have PCB with PCF8574T [...] I would like to display characters using python program with smbus. Hi, we have the same I2C backback. I slightly modified a script found somewhere (sorry for the poor credits, I don't remember where...) and it's working really well. Download it @ https://...
by dentex
Fri Oct 07, 2016 10:23 am
Forum: Beginners
Topic: GPIO0 and GPIO1 as output pins
Replies: 9
Views: 5583

Re: GPIO0 and GPIO1 as output pins

I'm not sure if it will help you but if you can free up pins 3 & 5 then you can add i2c input / output expanders giving you a lot more i/o pins (you can add upto 8 mcp23016, which would give you 16 i/o pins each). Hello Doug, Yes I know that, thanks. :) I will be using one MCP23017 later on for wit...
by dentex
Fri Oct 07, 2016 8:45 am
Forum: Beginners
Topic: GPIO0 and GPIO1 as output pins
Replies: 9
Views: 5583

Re: GPIO0 and GPIO1 as output pins

joan wrote:There has always been a 64k limit for a single image. Have you hit that limit? I'm not aware of any restriction per user.
I was at 53k with the 2nd image... Anyway no problem, I used imgur.
Thanks mate,
Bye!
by dentex
Fri Oct 07, 2016 8:37 am
Forum: Beginners
Topic: GPIO0 and GPIO1 as output pins
Replies: 9
Views: 5583

Re: GPIO0 and GPIO1 as output pins

joan wrote:I'd just configure them as outputs. I'm currently generating servo pulses on GPIO 0/1 on my Pi3 and nothing is obviously broken.
Thanks for the test!
Really helpful.
I'll go for it!


PS: it seems I cannot attach images anymore :(
by dentex
Fri Oct 07, 2016 8:31 am
Forum: Beginners
Topic: GPIO0 and GPIO1 as output pins
Replies: 9
Views: 5583

Re: GPIO0 and GPIO1 as output pins

Well, for the question (2), it seems they don't have any resistor:
Image
by dentex
Fri Oct 07, 2016 8:23 am
Forum: Beginners
Topic: GPIO0 and GPIO1 as output pins
Replies: 9
Views: 5583

Re: GPIO0 and GPIO1 as output pins

I believe you will be fine as long as you don't switch them into I2C mode (ALT0). Setting them as normal inputs or outputs should be okay. Hello joan, another couple of things: 1) is there anything I must configure at boot? Or am I just fine with exporting them as output? 2) do you know if there ar...
by dentex
Fri Oct 07, 2016 8:18 am
Forum: Beginners
Topic: GPIO0 and GPIO1 as output pins
Replies: 9
Views: 5583

GPIO0 and GPIO1 as output pins

Hello, for the project I'm working on, I'm literally out of GPIO pins. I'm using all of them. I was thinking about a couple of other things to do, but I would need 2 more pins. I'm only left with the GPIO0 and GPIO1 pins, marked as ID_SC and ID_SD. I know they seems to be "reserved" for usage with s...
by dentex
Wed Oct 05, 2016 9:45 am
Forum: Troubleshooting
Topic: RPi3 booting with Read-Only root filesystem
Replies: 0
Views: 311

RPi3 booting with Read-Only root filesystem

Today I wanted to continue to work on a certain DIY project involving a RPi3, but I found nothing started at boot as it shoud. The filesystem was mounted read-only. Everything work if I do: sudo mount -o remount,rw / ...but I don't know what happened and where to look for a solution. By chance, I di...
by dentex
Sun Oct 02, 2016 8:05 pm
Forum: Python
Topic: PCF8574 + 20x4 LCD help
Replies: 8
Views: 6737

Re: PCF8574 + 20x4 LCD help

Even this post is a little bit old ... I started with the code and the hints here, but I thought there is space for improvement. So I double checked the documentation of the HD44780U controller and modified the code. It works with and without backlight and it also allows to not double initialize af...
by dentex
Sat Oct 01, 2016 1:50 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Debugging a I2C 20x4 LCD [SOLVED - hardware issue]
Replies: 27
Views: 5191

Re: Debugging a I2C 20x4 LCD

SOLVED!!!! It was a stupid "hardware" issue... I was checking every pin on the PCF8574T to see where each LCD pin was connected to... and I noticed that although a track from IC pin 9 (P4) seemed to be connected to the LCD's pin 11 (D4), the IC pin was actually slightly bended upwards and it wasn't ...
by dentex
Sat Oct 01, 2016 10:27 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Debugging a I2C 20x4 LCD [SOLVED - hardware issue]
Replies: 27
Views: 5191

Re: Debugging a I2C 20x4 LCD

That doesn't look like a MCP23017. To double check I suggest you remove the power and ground wires from the chip and then replace to make sure the chip is reset. Then try the test once more. Done. Same result (after this test, the LCD remains with no back-light). On the I2C back-pack, the IC is mar...
by dentex
Sat Oct 01, 2016 10:09 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Debugging a I2C 20x4 LCD [SOLVED - hardware issue]
Replies: 27
Views: 5191

Re: Debugging a I2C 20x4 LCD

It might be worth trying to see if the device is a MCP23017 or not. After boot, and before trying to talk to the chip, try the following. $ sudo pigpiod $ pigs i2co 1 0x27 0 0 $ pigs i2cwd 0 0 i2crd 0 18 18 255 255 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 $ pigs i2cc 0 Hello joan, this is what I get with th...
by dentex
Sat Oct 01, 2016 8:17 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Debugging a I2C 20x4 LCD [SOLVED - hardware issue]
Replies: 27
Views: 5191

Re: Debugging a I2C 20x4 LCD

Thanks for the suggestions, I already tried both libraries... Still nothing.
by dentex
Wed Sep 28, 2016 3:22 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Debugging a I2C 20x4 LCD [SOLVED - hardware issue]
Replies: 27
Views: 5191

Re: Debugging a I2C 20x4 LCD

@Trevor You do wonderful things, as I can see at https://www.cpmspectrepi.uk/raspberry_pi/MoinMoinExport/AdafruitRasPiPermaProtoFullI2cDualLCD.html Needless to say they're too far from me to reach. But thanks anyway. @joan ...The init method allows you to specify the position of B4, BL, E, RW, RS. I...
by dentex
Tue Sep 27, 2016 2:09 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Debugging a I2C 20x4 LCD [SOLVED - hardware issue]
Replies: 27
Views: 5191

Re: Debugging a I2C 20x4 LCD

No luck until now. The seller sent me a datasheet, but it seems to be for another LCD... It's for the J204A while mine is marked as 2004A... I don't know if it's the same thing and other than that, the PDF it's like Arab to me: https://drive.google.com/open?id=0B1Ewr9YqTtiCX0VtRGlSSjZ4Tjg So I decid...
by dentex
Sun Sep 25, 2016 7:49 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Debugging a I2C 20x4 LCD [SOLVED - hardware issue]
Replies: 27
Views: 5191

Re: Debugging a I2C 20x4 LCD

Thanks guys. At least I have something to try. @Trev I'm waiting for a couple of those level-shifters. They are the generic F type (that seems the same of the red D one). They were advertised as I2C level-shifters, bidirectional. @joan Thanks for the hint on the initialization. I'll search for more ...
by dentex
Sun Sep 25, 2016 7:04 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Debugging a I2C 20x4 LCD [SOLVED - hardware issue]
Replies: 27
Views: 5191

Re: Debugging a I2C 20x4 LCD

@dentex this might be a "red herring" but are you using a 5V display + I2C backpack (powered by 5V) without any level-shifters (I2C compatible)? (I've always used such, even though some I2C devices can respond to 3.3V I2C levels). If you're not using level-shifters it's been suggested that a diode ...
by dentex
Sun Sep 25, 2016 6:41 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Debugging a I2C 20x4 LCD [SOLVED - hardware issue]
Replies: 27
Views: 5191

Re: Debugging a I2C 20x4 LCD

My example at http://abyz.co.uk/rpi/pigpio/examples.html#Python_i2c_lcd_py defaults to address 0x27 so may be compatible with your backpack. Thanks Joan, I'll try your library tomorrow and I'll let you know how it goes. Sorry for the delay... Just tried your library, but nothing... the LCD stays bl...
by dentex
Thu Sep 22, 2016 5:39 pm
Forum: Automation, sensing and robotics
Topic: GPIO strange behaviour at boot
Replies: 2
Views: 663

Re: GPIO strange behaviour at boot [SOLVED]

I assume you are starting servoblaster at boot. Presumably servoblaster is controlling the GPIO and overriding the gpio commands. O. M. G. :shock: I do have a `/etc/init.d/servoblaster` and after boot, `sudo cat /dev/servoblaster-cfg` returns: p1pins=7,11,12,13,15,16,18,22 p5pins= Servo mapping: 0 ...
by dentex
Thu Sep 22, 2016 4:33 pm
Forum: Automation, sensing and robotics
Topic: GPIO strange behaviour at boot
Replies: 2
Views: 663

GPIO strange behaviour at boot

Hello guys, I'm facing a very strange behaviour (at least for what I understand) in regards to how the GPIO on my RPi work after boot up. I'm using a RPi 3 model B and Debian Jessie, all up to date, including the firmware via rpi-update. I even bought another RPi, thinking I fried some GPIO pins (I ...
by dentex
Mon Sep 19, 2016 5:57 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Debugging a I2C 20x4 LCD [SOLVED - hardware issue]
Replies: 27
Views: 5191

Re: Debugging a I2C 20x4 LCD

Don't worry... Thanks again Trev.

I suspected those black hard material drops on the back were the "IC blobs" you were referring to...

We'll see what I can do.
by dentex
Mon Sep 19, 2016 1:06 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Debugging a I2C 20x4 LCD [SOLVED - hardware issue]
Replies: 27
Views: 5191

Re: Debugging a I2C 20x4 LCD

FTrevorGowen wrote:...please post a photo! )
Trev.
Sure! It's just a few messages above. The one with the "2004A" mark on its back.

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