Search found 106 matches

by cef
Sun Mar 23, 2014 11:02 pm
Forum: 4x4x4 RGB Cube
Topic: Debug
Replies: 0
Views: 2120

Re: Debug

The main loop repeats after it finishes. You need to put some delays in there to stop the program from doing anything while displaying those LEDs. (eg: sleep(500) - which is 500 millseconds), before it moves on to the next part. Otherwise what happens is: Sets the display to BLACK (all off). Immedia...
by cef
Fri Feb 28, 2014 7:23 am
Forum: LeoStick
Topic: reading analogue voltages
Replies: 3
Views: 4504

Re: reading analogue voltages

Hi Luke, 1. The issue applies to ALL fields (not just resistors, but things like calculating voltages, power loads, etc). Also, the issue applies if the value is very large or very small, so ANY value with an exponent at all may appear as though it doesn't have one. In the specific value I quoted, t...
by cef
Thu Feb 20, 2014 9:33 pm
Forum: Experimenters Kit
Topic: Question about project 4
Replies: 3
Views: 6483

Re: Question about project 4

Looks like the board isn't at /dev/ttyACM0 anymore. From a command prompt, look at the output of the 'dmesg' command. It will list all the devices found (in order) and in there you may see something referring to /dev/ttyACM0 or some other number (eg: ttyACM1). Whatever the last one is, change the se...
by cef
Thu Feb 13, 2014 5:59 am
Forum: HBRIDGE: H-Bridge Motor Driver Shield
Topic: Controlling a1.7A/Phase 3v stepper (sparkfun ROB-10846)
Replies: 7
Views: 11135

Re: Controlling a1.7A/Phase 3v stepper (sparkfun ROB-10846)

Q: Which code are you using to control this?

If you're using your own code, how long are you holding the signal at the appropriate logic level before returning it to the default? If the pulse is too short, the driver may not be recognising the pulse as valid.
by cef
Tue Feb 11, 2014 9:38 pm
Forum: HBRIDGE: H-Bridge Motor Driver Shield
Topic: Controlling a1.7A/Phase 3v stepper (sparkfun ROB-10846)
Replies: 7
Views: 11135

Re: Controlling a1.7A/Phase 3v stepper (sparkfun ROB-10846)

I would first look at your 12V 2A supply. I'd see if you could use a slightly larger supply (eg: 12V 3-5A) just to avoid current spikes taking the usage over the 2A mark. The more the voltage varies, the less reliable your steps will be. As the Arduino regulates that voltage down to 5V, it won't see...
by cef
Fri Feb 07, 2014 9:54 pm
Forum: LCDK: LCD & Keypad Shield
Topic: Arduino Due
Replies: 8
Views: 10683

Re: Arduino Due

The level converter will only convert digital signals.

The analog lines really require you change the reference voltage line as John mentioned.
by cef
Sun Feb 02, 2014 10:55 am
Forum: Random Chit-Chat
Topic: Melbourne HackerSpace
Replies: 2
Views: 2725

Re: Melbourne HackerSpace

I'm one of the (many) people involved with the Melbourne "Connected Community" HackerSpace (aka CCHS). I mainly help out with the 3D Printing and CNC nights, but also help out in a number of other ways (eg: the Website, Twitter, etc). FWIW: The website is at http://www.hackmelbourne.org/ and has a c...
by cef
Sat Feb 01, 2014 7:01 pm
Forum: Random Chit-Chat
Topic: 74HC595 in practice ?
Replies: 4
Views: 3918

Re: 74HC595 in practice ?

Here's a spec sheet for the 74HC595: http://www.nxp.com/documents/data_sheet/74HC_HCT595.pdf Note there are 4 input pins apart from the serial data (DS): MR SHCP STCP OE Note that MR and OE are active low, so they need to be tied low (0V) to be used, and are otherwise high. You feed in data via DS, ...
by cef
Sat Jan 25, 2014 6:06 am
Forum: OLED128 Display
Topic: [Solved] Raspberry Pi garbled image
Replies: 6
Views: 4413

Re: Raspberry Pi garbled image

Off the top of my head: First thing I would check is how long the cable you have between the Raspberry Pi and the OLED display is? If the cable is too long, complicated text and graphics might get corrupted. Second is to check your 5V power supply for the Raspberry Pi is sticking to 5V and not saggi...
by cef
Sat Jan 25, 2014 5:57 am
Forum: HBRIDGE: H-Bridge Motor Driver Shield
Topic: hbridge issue
Replies: 7
Views: 6339

Re: hbridge issue

Technically, that's correct, but it's a bit of a misnomer as they're not really polarised like that. It's best to be consistent, and it "does" affect the direction your motor spins. Because of the way stepper motors work, you want them either connected both forward or both reversed. The main thing t...