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by keithellis
Wed Apr 30, 2014 11:36 am
Forum: Beginners
Topic: New Out Of Box Software login
Replies: 10
Views: 11726

Re: New Out Of Box Software login

It is possible to complete a NOOBS headless install, however a couple of files needs to be edited before booting the Pi up for the first time.

I have produced a video highlighting how to do this. Take a look
http://bit.ly/NOOBS-headless
Keith.
by keithellis
Mon Apr 14, 2014 9:11 pm
Forum: Beginners
Topic: Monitor the Pi through USB on PC.
Replies: 7
Views: 5439

Re: Monitor the Pi through USB on PC.

One way of doing this is by using a USB serial console cable. The console cable connects to the USB port of your computer and to the GPIO serial pins on the Raspberry Pi. This can also be used to power the Pi so no need to plug a power lead into the Pi USB port, though it is very easy to connect up ...
by keithellis
Sun Apr 13, 2014 6:30 pm
Forum: Other projects
Topic: 5v regulator not working as expected
Replies: 8
Views: 2318

Re: 5v regulator not working as expected

The 22uF cap did the trick, getting a steady 5v output now. Thanks everyone.
Keith.
by keithellis
Sun Apr 06, 2014 9:30 am
Forum: Networking and servers
Topic: headless wifi setup: easiest approach?
Replies: 24
Views: 17312

Re: headless wifi setup: easiest approach?

That is an answer, but the model A is much better when running off batteries for robot or remote projects. It is also cheaper.
by keithellis
Sun Apr 06, 2014 8:39 am
Forum: Networking and servers
Topic: headless wifi setup: easiest approach?
Replies: 24
Views: 17312

Re: headless wifi setup: easiest approach?

I have several Rpis that I run headless. All I do when starting with a new Rpi is to boot with the ethernet connected, login via ssh, drop in my interfaces file and reboot. Poof - it is up and running. No config for supplicant needed. But what do you do if you have a model A without Ethernet port. ...
by keithellis
Thu Mar 20, 2014 9:23 pm
Forum: Teaching and learning resources
Topic: Raspberry Pi video Tutorials
Replies: 2
Views: 1767

Re: Raspberry Pi video Tutorials

I've just added another tutorial, this one is the first part of two and explains how to setup SSH or Secure Shell as it is also know. video can be found here http://bit.ly/SSH-part1
by keithellis
Tue Mar 11, 2014 5:44 pm
Forum: Python
Topic: Reading a GPIO output
Replies: 11
Views: 4935

Re: Reading a GPIO output

You can read an output from another script using RPi.GPIO. Just GPIO.setup() it as an output in your second script and read it using GPIO.input() Also don't do a GPIO.cleanup() at the end of your script and do a GPIO.setwarnings(False) at the start. You can use GPIO.setwarnings(False), but you shou...
by keithellis
Tue Mar 11, 2014 3:08 pm
Forum: Python
Topic: Reading a GPIO output
Replies: 11
Views: 4935

Re: Reading a GPIO output

You can read an output from another script using RPi.GPIO. Just GPIO.setup() it as an output in your second script and read it using GPIO.input() Also don't do a GPIO.cleanup() at the end of your script and do a GPIO.setwarnings(False) at the start. You can use GPIO.setwarnings(False), but you shou...
by keithellis
Mon Mar 10, 2014 9:28 pm
Forum: Python
Topic: LED Control
Replies: 4
Views: 1016

Re: LED Control

We need to see the indentation, click the code button in the edit bar during composing a post and past your code in-between the code tags. GPIO.cleanup() should be at the end of your code block. It is possible that the input wired up to the switch is not pulled high or low and could therefore be flo...
by keithellis
Mon Mar 10, 2014 9:01 pm
Forum: Other projects
Topic: 5v regulator not working as expected
Replies: 8
Views: 2318

Re: 5v regulator not working as expected

Ok, I'll get the capacitor on order and try again, thanks guys.
by keithellis
Mon Mar 10, 2014 9:00 pm
Forum: Other projects
Topic: 5v regulator not working as expected
Replies: 8
Views: 2318

Re: 5v regulator not working as expected

If the regulator output is higher than expected then the ground wire to pin 2 is broken or has bad contact to breadboard. Richard S. Just checked, I'm getting 0.1ohm between negative battery terminal and a jumper plugged into bread board on same track as negative pin of regulator, and I am getting ...
by keithellis
Mon Mar 10, 2014 8:46 pm
Forum: Other projects
Topic: 5v regulator not working as expected
Replies: 8
Views: 2318

Re: 5v regulator not working as expected

I believe so, I have checked and double checked.

EDIT:
Only think I have not done is connect the 22uF capacitor. Will this make a difference?
by keithellis
Mon Mar 10, 2014 8:35 pm
Forum: Other projects
Topic: 5v regulator not working as expected
Replies: 8
Views: 2318

5v regulator not working as expected

Hello, I have a robot project ongoing, I would like to power my Pi from the onboard battery pack (6 x 1.5v AA cells) 9v supply. I have bought a Texas Instruments 5v regulator part No. LM2940CT-5.0 from CPC, http://cpc.farnell.com/jsp/search/productdetail.jsp?SKU=SC08320 Data Sheet here http://www.jo...
by keithellis
Thu Mar 06, 2014 11:48 am
Forum: Automation, sensing and robotics
Topic: Rural Pi
Replies: 34
Views: 11085

Re: Rural Pi

Ok, not sure if this is possible, but it could be. Using a USB to serial UART converter the 3G USB dongle could be wired up to the UART pins on the Pi The converter can be powered from the Pi via a transistor controlled by a GPIO pin. The converter could therefore be powered down in code. Just an id...
by keithellis
Tue Mar 04, 2014 9:18 am
Forum: Teaching and learning resources
Topic: Raspberry Pi video Tutorials
Replies: 2
Views: 1767

Raspberry Pi video Tutorials

Hello, Further to Carrie Anne's post here http://www.raspberrypi.org/archives/6359#comments I thought I should post here point to my YouTube channel. I cam currently building a Raspberry Pi robot based on the magician chassis and as I encounter challenges, I and producing video tutorials showing how...
by keithellis
Tue Feb 25, 2014 2:21 pm
Forum: Beginners
Topic: Some questions before buying my first Pi (for headless)
Replies: 3
Views: 652

Re: Some questions before buying my first Pi (for headless)

Hello, I'm going to buy my first Raspberry Pi and I have some questions. Beore reading just remember that I would need to do everything (including installing the OS) without a monitor and a keyboard , the only thing I can use is my laptop. I will not have a monitor for it, so I don't need a distro ...
by keithellis
Tue Feb 25, 2014 2:10 pm
Forum: Beginners
Topic: I2C Proximity Sensor
Replies: 4
Views: 3696

Re: I2C Proximity Sensor

You might want to remove the pull up resister on the Arduino board on the SCL and SDA lines. These will pull the voltage up to 5v (not good for the Pi) The Pi has pull up on the SCL and SDA lines up to 3v3 which the Arduino board will work with just fine.

Keith.
by keithellis
Tue Feb 25, 2014 12:45 pm
Forum: Python
Topic: i2c smbus pi to arduino
Replies: 1
Views: 792

Re: i2c smbus pi to arduino

What does your Arduino sketch look like?
by keithellis
Thu Feb 20, 2014 3:47 pm
Forum: Python
Topic: RPi.GPIO threaded callbacks
Replies: 5
Views: 2533

Re: RPi.GPIO threaded callbacks

Ok, sorted this now, I have used a global variable which is set 'True' when robot is moving forward (i.e. I do not want robot to detect obstacle when it is not moving forwards). If True and object detected then reverse. All working as intended now. Thank you all. @paddyg The reason I call stop() in ...
by keithellis
Sun Feb 16, 2014 10:50 pm
Forum: Advanced users
Topic: Static eth0 fallback
Replies: 21
Views: 4871

Re: Static eth0 fallback

Or my preferred option is to get. USB serial console cable.

http://bit.ly/headless_install

Keith.
by keithellis
Tue Feb 11, 2014 9:25 pm
Forum: Python
Topic: RPi.GPIO threaded callbacks
Replies: 5
Views: 2533

Re: RPi.GPIO threaded callbacks

I fixed my problem, almost I removed the drive_motor() from the while loop. the drive_motor() should only be called once and the wheels will continue to turn until stopped. Thus def object_detect(channel): avoid_object() def avoid_object(): drive_motor(80, ['leftMotorPin2']) while GPIO.input(17) == ...
by keithellis
Tue Feb 11, 2014 5:55 pm
Forum: Python
Topic: RPi.GPIO threaded callbacks
Replies: 5
Views: 2533

Re: RPi.GPIO threaded callbacks

Thanks, I've give that a go. I did start thinking along those lines, hence the

Code: Select all

avoid = False
variable I had declared, but not used.

Keith.
by keithellis
Tue Feb 11, 2014 11:14 am
Forum: Python
Topic: Speed control for the raspirobotboard
Replies: 10
Views: 1573

Re: Speed control for the raspirobotboard

In addition you have missed a 'd' off speedL on the second line listed below. def set_motors(self, speedL, left_dir, speedR, right_dir): self.speedLeft.ChangeDutyCycle(speeL) GPIO.output(LEFT_DIR_PIN, left_dir) self.speedRight.ChangeDutyCycle(speedR) GPIO.output(RIGHT_DIR_PIN, right_dir)
by keithellis
Tue Feb 11, 2014 11:12 am
Forum: Python
Topic: Speed control for the raspirobotboard
Replies: 10
Views: 1573

Re: Speed control for the raspirobotboard

You setup PWM on LEFT_GO_PIN twice

Code: Select all

       self.speedLeft = GPIO.PWM(LEFT_GO_PIN, 100)
       self.speedRight = GPIO.PWM(LEFT_GO_PIN, 100)
Maybe this is causing you problems
by keithellis
Mon Feb 10, 2014 10:16 pm
Forum: Python
Topic: RPi.GPIO threaded callbacks
Replies: 5
Views: 2533

RPi.GPIO threaded callbacks

Hello, I've got some code to control a two wheeled robot. I am trying to add a threaded callback which detects proximity, if triggered the robot will stop and turn until the proximity detector is clear again. The stop function is called fine, but the rotation of the robot is jumpy. I've had a multi ...

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