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by repton
Wed Oct 31, 2012 7:11 pm
Forum: Automation, sensing and robotics
Topic: 1-wire temperature logging
Replies: 23
Views: 17725

Re: 1-wire temperature logging

Hi mark, on my setup pins 1 and 3 are connected (soldered together), then just two wires connect back to the 1-wire USB adaptor. That is different though as you're using a USB host adapter and the poster was asking about using the kernel based 1-wire adapter connected to the GPIO connector. The maj...
by repton
Wed Oct 31, 2012 7:09 pm
Forum: Automation, sensing and robotics
Topic: 1-wire temperature logging
Replies: 23
Views: 17725

Re: 1-wire temperature logging

Just tried connecting a second DS18B20 to my current working one but ended up not being able to see any devices at all. I connected the first as in the diagram above which worked fine and I connected the second pin to pin to the first, still with just one 4k7 resistor. Is this correct? It should be...
by repton
Tue Oct 30, 2012 8:24 pm
Forum: Automation, sensing and robotics
Topic: 1-wire temperature logging
Replies: 23
Views: 17725

Re: 1-wire temperature logging

ale36 wrote:can some one tell me which is the best method?
The method in the image, i.e. power to 3V3, data to GPIO4, ground to ground, and a 4K7 resistor between GPIO4 and 3V3.

Paul
by repton
Thu Oct 18, 2012 4:56 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Injecting 12v on to the GPIO 5 volt pin to power RPi - don't
Replies: 16
Views: 3499

Re: Injecting 5v on to the GPIO 5 volt pin to power RPi - do

Answering my own post, I've now managed to route the traces so that the 0V is supplied on both pins 6 and 9 so there shouldn't be an issue. Paul It is not just the pins, it is the tracks on the PCB to the source. Paralleling up the pins is good but if at the end of the day the PCB tracks won't take...
by repton
Thu Oct 18, 2012 12:51 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Injecting 12v on to the GPIO 5 volt pin to power RPi - don't
Replies: 16
Views: 3499

Re: Injecting 5v on to the GPIO 5 volt pin to power RPi - do

My question is this: is the RasPi PCB designed in such a way that the traces from all of the ground connections are capable of carrying the full 1000mA the RasPi could potentially use? I'm asking as I had originally planned to connect +5V to pins 2 and 4, and 0V to pins 6 and 9 in order to spread t...
by repton
Wed Oct 17, 2012 3:51 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Injecting 12v on to the GPIO 5 volt pin to power RPi - don't
Replies: 16
Views: 3499

Re: Injecting 5v on to the GPIO 5 volt pin to power RPi - do

On the subject of powering your RasPi from the GPIO connector... I'm currently designing some expansion boards for the RasPi and wish to be able to power the RasPi from them via the GPIO connector. My question is this: is the RasPi PCB designed in such a way that the traces from all of the ground co...
by repton
Sat Oct 13, 2012 8:42 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Washing after soldering, is water OK?
Replies: 11
Views: 2832

Re: Washing after soldering, is water OK?

I've always just used normal flux cored lead based solder and find it works fine without any extra flux even on surface mount stuff.

Paul
by repton
Sat Oct 06, 2012 1:59 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Connecting I2C chips, breakout boards
Replies: 11
Views: 4676

Re: Connecting I2C chips, breakout boards

Here's a photo of my setup which I am using to test the kernel based 1-wire driver.
I'm using Adafruit's "Pi Cobbler" to connect the RasPi to the breadboard.

HTH,
Paul
by repton
Sat Sep 29, 2012 9:40 am
Forum: Automation, sensing and robotics
Topic: Temperature sensor
Replies: 12
Views: 13851

Re: Temperature sensor

The cheapest solution is a single DS18S20 or DS18B20 temperature sensor from Maxim and a 4.7k resistor and then use the kernel based 1-Wire driver. Connect the sensors 0V pin to GND, data to GPIO4 and power to 3V3 on the expansion header and then put the 4.7k resistor between the power and data line...
by repton
Fri Sep 28, 2012 7:18 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: kernel patch for Dallas 1-wire interface
Replies: 227
Views: 160968

Re: kernel patch for Dallas 1-wire interface

Is this sensor not supported by the kernel or is there just something wrong with my wiring? I know this isn't really much help but the kernel should support both the DS1S20 and DS18B20 and as far as I can tell your wiring is right (certainly that diagram is right). I'm using "3.2.27+ #171 PREEMPT" ...
by repton
Fri Sep 28, 2012 7:02 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: kernel patch for Dallas 1-wire interface
Replies: 227
Views: 160968

Re: kernel patch for Dallas 1-wire interface

Are the wee PCBs with the dual RJ45 sockets on your own design or are they available somewhere? They look kind of just what I need for a project.. I'm not sure what the rules on advertising are here so mods please let me know if I'm being naughty here... They are my design, I run a small home busin...
by repton
Thu Sep 27, 2012 2:36 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: kernel patch for Dallas 1-wire interface
Replies: 227
Views: 160968

Re: kernel patch for Dallas 1-wire interface

I had a play with this yesterday and with the latest kernel (downloaded via the rpi-update tool) it worked perfectly first time. For testing I've got it connected to four DS18B20 sensors, two of which are within a foot of the RasPi, the third is then at the other end of a 3m cat5 and then the last o...
by repton
Sat Jun 30, 2012 7:42 pm
Forum: General discussion
Topic: Power Supply : ILUV 3xUSB (1x1A 2x0.5A) £3.97 Del (UK)
Replies: 6
Views: 3828

Re: Power Supply : ILUV 3xUSB (1x1A 2x0.5A) £3.97 Del (UK)

Mine has also arrived and the power as measured on the board has gone from 4.2V with the first PSU to 4.3V with the new one. Still too low, so I'm starting to wonder if I've got a duff cable. A new one is on the way to try... Cable replaced with a good quality one and the voltage measured at te Ras...
by repton
Thu Jun 28, 2012 8:52 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Powering the Pi from GPIO
Replies: 23
Views: 11574

Re: Powering the Pi from GPIO

When they used relays, telephone exchanges used some low voltage -- 24 or 48V or something similar, but an awful lot of it. The power was fed to the relay banks from the transformers through two thick copper bus-bars, and we are talking inches thick of solid copper. To this day telco kit still runs...
by repton
Fri Jun 22, 2012 3:21 pm
Forum: General discussion
Topic: Power Supply : ILUV 3xUSB (1x1A 2x0.5A) £3.97 Del (UK)
Replies: 6
Views: 3828

Re: Power Supply : ILUV 3xUSB (1x1A 2x0.5A) £3.97 Del (UK)

Mine has also arrived and the power as measured on the board has gone from 4.2V with the first PSU to 4.3V with the new one. Still too low, so I'm starting to wonder if I've got a duff cable. A new one is on the way to try...

Paul
by repton
Sun Jun 17, 2012 10:03 am
Forum: General discussion
Topic: Power Supply : ILUV 3xUSB (1x1A 2x0.5A) £3.97 Del (UK)
Replies: 6
Views: 3828

Re: Power Supply : ILUV 3xUSB (1x1A 2x0.5A) £3.97 Del (UK)

I've just ordered one of those from Currys too, we'll see how well it works when it arrives. I'm currently using a cheapo one that came as part of an "R-Pi starter pack" I got off eBay that consisted of the PSU+cable, keyabord, mouse, hdmi cable and a pre loaded 8GB SD card. However I ran into probl...

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