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31  Development / Other Hardware Development / Re: Doubling up ICSP pins - recommendations? on: March 20, 2013, 08:16:16 am
I probably wasn't clear enough in my goals - a typical programmed scenario would be each of the 5 I/Os on the '85 would be outputs connected to LEDs (with approprate resistor), however I assumed when the device is being programmed, having the LED still connected to the same pins as being used for the ISCP would cause problems, especially if the programmer could not provide the current to drive the LED too.

What I wasn't sure of was if all the '85 outputs were connected to transistors to switch the LED current, whether that would still be consided 'risky' for the programmer?

In the name of experimentation I tried it out - with LEDs direct, definite fail with programmer failing to detect the device. But with 85 driving LEDs trough uln2803 gates, I was able to program successfully.

I fully appreciate just because it appears to work doesn't mean it's not actually doing untold or undetected damage, which is what prompted the question in the first place.

But as I understand it with the 2803, I'm only ever connecting outputs to inputs (run time) and outputs & inputs to inputs (program time) but never outputs to outputs so it should be safe.

32  Development / Other Hardware Development / Re: Doubling up ICSP pins - recommendations? on: March 18, 2013, 10:02:17 am
Ideally I was going for the very minimum component count due to size limitations (I'm already using an SMD package which would make programming outside of the board impossible once assembled). I did wonder if driving the LED through a transistor rather than direct would prevent the programmer being affected though...
33  Development / Other Hardware Development / Doubling up ICSP pins - recommendations? on: March 18, 2013, 07:53:43 am
Are there any recommendations or guidelines as to what you can attach to the pins shared with the ICSP interface - I'm currently working on a Tiny85 project that I would like to leave ICSP access to, but this obviously ties up most of the I/Os - I'm looking at using LEDs on most but may have a jumpered input on one pin.

34  Using Arduino / Microcontrollers / Re: Avrdude Verifcation failure when using -q switch on: March 14, 2013, 03:20:13 am
I don't think it's the programmer as it worked fine with avrdude 5.10 and has been working for a couple of years. Don't have another '85 but I do have a '2313 so I'll try that as soon as I get a chance again
35  Using Arduino / Microcontrollers / Re: Avrdude Verifcation failure when using -q switch on: March 13, 2013, 02:11:18 pm
Literally just tried it - still the same problem

Also burnt the fuses for 8 / 8 and 8 / 1 MHz - still fails at both settings smiley-sad

36  Using Arduino / Microcontrollers / Re: Avrdude Verifcation failure when using -q switch on: March 13, 2013, 04:04:56 am
I tried the 5.11.1 patch last night but no luck - problem still exists. I have just realised that this is still a 'virginal' Tiny85 - the fuses have not yet been set (due to a possible issue with VisualMicro) so that may have a bearing. it's supposed to be on 8Mhz internal clock but is currently on 1Mhz I think. I'll set teh fuses separately tonigth and see if that changes anything...
37  Using Arduino / Microcontrollers / Re: Avrdude Verifcation failure when using -q switch on: March 12, 2013, 07:48:15 am
A bit more investigation shows that it fails with avrdude v5.11 but succeeds with v5.10

I was wondering if it could be a timing issue, since outputting the ### progress markers on the console might be slowing things down enough to affect timings somewhere...
38  Using Arduino / Microcontrollers / Avrdude Verifcation failure when using -q switch on: March 11, 2013, 08:22:02 am
This isn't Arduino per se, but just wondering if anyone's come across this before - I was initially using the VisualMicro IDE to upload to a Tiny85 using a TinyISP programmer, but have now removed the IDE from from the suspects list and can reproduce with just avrdude and my compiled .hex

Basically this works:
avrdude -c usbtiny -p attiny85 -U flash:w:Tiny85Test.hex

but adding the -q switch like this fails
avrdude -c usbtiny -p attiny85 -q -U flash:w:Tiny85Test.hex

with the following error
avrdude: verification error, first mismatch at byte 0x00c0
         0xb0 != 0x68
avrdude: verification error; content mismatch

I'm using the Arduino 1.0.3 fileset and the Avrdude that that contains...
Unfortunately VisualMicro adds the -q when it builds teh Avrdude command line, so the upload always fails.

39  Using Arduino / General Electronics / Re: Cheap Uk Supplier for 2.54mm Header Pin Connectors ? on: February 06, 2013, 08:30:27 am
Rapid are good pricewise but like most of the larger UK suppliers have a hobbyist-killing shipping policy: £5 +VAT on all orders under £35 + VAT, so if you just want a few odds & sods you have to go elsewhere....

There are a few good smaller suppliers if you google around - Earthshine comes to mind.
40  Using Arduino / General Electronics / Re: uuuggghhhh ebay and common RGB leds on: January 11, 2013, 08:01:24 am
Remember you're not buying from eBay, eBay is just a conduit that connects you with any number of potential suppliers.

Those suppliers you eventually buy from may be highly reputable selling A1 grade stuff, or they may be cowboys selling junk. It's up to you as a buyer to do the due dilligence....
41  Using Arduino / General Electronics / Re: Cheap PCB fab? on: December 07, 2012, 08:07:35 am
The boards were typically made in three working days, and postage took about 8-10 days.

I've done 2-3 orders this autumn and have seen more like 3 weeks for delivery to the UK
42  Using Arduino / Microcontrollers / Re: Which ATmega328 (blank) from DigiKey? on: July 31, 2012, 07:02:15 am

The chip's that I ordered from sparkfun are 328P-PU with a #1107 on them. They work fine with no fuss but I have to chose one of the older boards in the menu. The chip that came in my UNO has a # 1123 on it.

Those extra numbers are manufacture dates in the form 7th (or 23rd) week of 2011 - this is a common stardard on most components.
43  Using Arduino / Programming Questions / Re: modifying SoftPWM for attiny on: May 10, 2012, 02:17:34 pm
I managed to get it working on the 2313, and also managed to fix some bugs that prevented output 0 being used as PWM (these have now been fixed in the latest Arduino 1.0 version of SoftPWM I noticed the other day)

Can't remember what I did now - I'll have to re-familiarise myself with teh code again....

I did find that the structures consume a huge amount of RAM - I could only get 8 outputs PWMing and more and really strange things start happening....
44  Development / Other Hardware Development / Re: Big holes in Eagle...? on: March 28, 2012, 02:01:44 am
Doh! I knew there's be a simple option smiley

45  Development / Other Hardware Development / Big holes in Eagle...? on: March 27, 2012, 12:49:26 pm
I'm trying to put a 3mm hole in my board for a locating peg, but I can't seem to get just a hole. if I use MOUNT-HOLE3.0 it also places a huge pad and keepout around the hole. I just want the hole. Is there some other library part that is just the hole with no outside pad, or do I have to create one myself?

Cheers in advance!
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