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by sukisan
Sun Nov 23, 2014 7:18 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: B+, i2c-0, and Jessie
Replies: 58
Views: 11734

Re: B+, i2c-0, and Jessie

Hi the normal I2C doesn't have external 1K8 pullups for nothing you know! Internal pullups are extremely weak, in the 50K region, to0 weak to reliably work as I2C pullups. Been there ... got burned by it! When I2C doesn't work, add them, even when you think you don't need them! How do you read resis...
by sukisan
Sun Nov 23, 2014 2:39 pm
Forum: Advanced users
Topic: How to use second I2C on B+
Replies: 7
Views: 5616

Re: How to use second I2C on B+

Thanks again!

Your hint brought me to B+ disable ID_EEPROM. Just as follow up for someone who might stumble over this thread.
ShiftPlusOne wrote:The firmware will check for an attached eeprom first, but that shouldn't affect your device.
I'm not afraid anymore ;-)
by sukisan
Sun Nov 23, 2014 2:24 pm
Forum: Advanced users
Topic: How to use second I2C on B+
Replies: 7
Views: 5616

Re: How to use second I2C on B+

Thanks joan for the quick response!

The A+ is already ordered. I'm still a bit afraid I'll fry it by just connecting the board, due to the explicit warning - I'll let you know how it went ;-)
by sukisan
Sun Nov 23, 2014 2:01 pm
Forum: Advanced users
Topic: How to use second I2C on B+
Replies: 7
Views: 5616

How to use second I2C on B+

Hi, I'm using both I2C interfaces on my model B. To do so, I configured GPIO 28 & 29 to be in their ALT0 function. I'd really love to switch to the A+, because it's much smaller. I already figured out that the A+ and B+ pinouts are identical. Question is: is it save to connect an I2C device to GPIO0...
by sukisan
Thu Sep 25, 2014 11:09 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Enable both I2C Busses
Replies: 58
Views: 29674

Re: Enable both I2C Busses

I'm using bgreat's python solution to work with both I2C busses. He also mentions one needs to add your own resistors. This and that suggest that you can simply configure pull up resistors. Can anyone confirm this works? bgreat? I dug around in the bcm2835 source and ported the methods along with th...
by sukisan
Wed Jul 09, 2014 3:42 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: TCL5947 via SPI from Python
Replies: 10
Views: 2548

Re: TCL5947 via SPI from Python

oh wow, this looks handy.

But for now, problem solved!

However, I can't completely explain the problem origin yet. Solution first: I had to pull up the outputs to V+. I used a 10k resistor. I guess it has something to do with the outputs being low active and wired as open drain?
by sukisan
Wed Jul 09, 2014 3:13 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: TCL5947 via SPI from Python
Replies: 10
Views: 2548

Re: TCL5947 via SPI from Python

I installed the bcm2835 library and compiled Python3.4 from source to be able to run FPulse. I also copied fpluse/bin/fpulse to fpulse/fpulse.py to be able to run it without installing the module. Now I'm able to run sudo python3.4 fpulse.py tlc5947 conf/morse.conf but I still don't see any PWM :-( ...
by sukisan
Tue Jul 08, 2014 8:00 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: TCL5947 via SPI from Python
Replies: 10
Views: 2548

Re: TCL5947 via SPI from Python

It's a pity it's a 4-wire device. hehe white p1-4 5V ---> V+ brown p1-6 GND ---> used as reference for the oscilloscope I think you've been 1 off here, right? brown p1-9 GND ---> /OE blue p1-11 GPIO17---> LAT yellow p1-19 MOSI ---> DIN orange p1-23 SCLK ---> CLK brown p1-25 GND ---> GND
by sukisan
Tue Jul 08, 2014 7:21 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: TCL5947 via SPI from Python
Replies: 10
Views: 2548

Re: TCL5947 via SPI from Python

Please find attached four pictures...well, three pictures as it's the limit, the fourth is only highres available.

Other three links clickable:
IMG_7950
IMG_7951
IMG_7953
by sukisan
Mon Jul 07, 2014 10:44 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: TCL5947 via SPI from Python
Replies: 10
Views: 2548

TCL5947 via SPI from Python

Hey guys, I'm trying to use the Adafruit 24-Channel 12-bit PWM LED Driver with an SPI interface from Python. I checked that SPI itself is working by using a small C program . The problem is, I can't convince the board to produce any meaningful output. All I get is a dirty ground signal on all channe...

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