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Forum Index : Microcontroller and PC projects : Buying parts for MicroMite in the UK
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| cosmic frog Senior Member  Joined: 09/02/2012 Location: United KingdomPosts: 284 |
Just had a look at a few web sites for the parts for the MicroMite but I seem to be having problems finding a realistic price for the 10μF multilayer ceramic/47μF tantalum cap. Most of them are more expensive than the chip itself! The cheapest I can find the chip is RS Components at £3.05 each and the most expensive cap is an amazing £168.45 from Farnell. Is anyone else having problems with prices? I've found cheaper prices for the caps but have to buy 150 of them. |
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| hitsware Guru  Joined: 23/11/2012 Location: United StatesPosts: 535 |
try here |
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| WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2817 |
Hi cosmic frog You will find a cheaper 47uF capacitor that meets all the required specifications here. Even though it is a SMD cap, it can be soldered directly onto the two relevant pins of the 28-pin DIP PIC. And under £1 each. PM me if you are interested in a couple of these caps! Do take a look at www.MicroMite.org for other MicroMite components & add-ons. Please get in touch with me. Where in the UK are you? WW For everything Micromite visit micromite.org Direct Email: whitewizzard@micromite.o |
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| cosmic frog Senior Member Joined: 09/02/2012 Location: United KingdomPosts: 284 |
Thanks for the info. hitsware, Those caps are 2ohm the manual says it must be less than 1ohm but thanks for having a look for me. WhiteWizzard, that site looks good thanks. P.S. I'm in UK Sheffield. Thanks. Dave. |
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| hitsware Guru Joined: 23/11/2012 Location: United StatesPosts: 535 |
> Those caps are 2ohm Duh ..... I gotta remember that ! I usually pay no attention to that spec. |
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Grogster Admin Group  Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
Oh...my...God....   
What's it made from? Gold dust? Smoke makes things work. When the smoke gets out, it stops! |
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| WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2817 |
Come on Grogs, so how many do you want to buy? If you order more than 10 I will jump on a plane at Heathrow (I'm just down the road from there) and personally deliver them to you! I will even chuck in a free MicroMite Module for you too. Just let me know how many you need. I can deliver them by Monday next week  . . .
For everything Micromite visit micromite.org Direct Email: whitewizzard@micromite.o |
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| robert.rozee Guru Joined: 31/12/2012 Location: New ZealandPosts: 2350 |
grab an old PC motherboard or just about any expansion card and rob a tantalum capacitor from it. any value from about 10uF upwards is likely to be ok - i used 22uF without any trouble. what we need is a chinese ebay seller who sells the 32MX150 along with a suitable capacitor for $5 delivered! rob :-) |
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MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
Is a Thai Seller for just a little more ok? :) Unprogrammed DIP 32MX150 + capacitor for 5US$ plus $2US$ for shipping max 5 DIPS or 8 SOICs/TQFP. Need more then 5 pieces, then shipping is around 5US$, Microblocks. Build with logic. |
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| WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2817 |
Not quite as cheap as $5 but this is GUARANTEED to work!
For everything Micromite visit micromite.org Direct Email: whitewizzard@micromite.o |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3816 |
In case anyone wants to do that... how to recognise the right one(s) and will they have low enough ESR? John |
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| MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
That is a little over the top WW. The chips come from the factory here in Thailand, about 30kms from where i am. The capacitors i have here are made by AVX and i get those from a electronics supplier who imports them directly, btw they look exactly like the ones you have in the picture. And they are made in China. :) Retail price for those is about 0.60$ for one piece and come down to about 0.40$ for more then 100. I bet most sellers you can find on ebay have exactly the same parts. There are always exeptions, but that is why on ebay at least you can use the positive feedback as an indicator. Just an observation, would it not be better to supply a through hole capacitor? A DIP combined with an smd part is not really working well for most hobby uses. And throw in a 10k resistor for the reset line pullup and it will be complete. Microblocks. Build with logic. |
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| WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2817 |
Hi TZA, The idea of supplying the SMD cap is so that it can be soldered directly onto pins 19&20. This way you still end up with a single 28-pin DIP MicroMite. I used this method very successfully during my first days of Beta testing and seems to make sense to continue to use the two components this way. Regarding the 10K resistor, you don't need it if you are not going to be programming the PIC via ICSP. This kit is designed as a MINIMUM part count MicroMite to allow beginners to follow the instructions in Geoff's manual. I hope my reasoning of supply a SMD cap & pre-programmed DIP PIC now makes more sense to you.
Perhaps I should offer it pre-soldered instead if you think people can't solder onto two DIP pins? What do you think? (Mind you, it wouldn't be a 'kit' then!). WW For everything Micromite visit micromite.org Direct Email: whitewizzard@micromite.o |
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| MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
Hi WW, I have the experience that most people that start to learn microcontrollers can unfortunately not solder very well. A breadboard and all through hole parts or a small pcb with all the necessary parts on it that can be used on or next to a breadboard like yours is the best way to go. Presoldered would be nice, but that means extra work and indeed it would not be a kit anymore. Choices...choices.... :) I think after a while it will be clear just by looking what sells best. Microblocks. Build with logic. |
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| robert.rozee Guru Joined: 31/12/2012 Location: New ZealandPosts: 2350 |
my experience is that even qualified electronics engineers can no longer solder very well. it is an unfortunate thing that society has arrived at the point where people simply neglect to obtain the 'basic skills' necessary before embarking on an enterprise. people who can not add numbers together become maths teachers, people with no climbing or survival skills try to climb tall mountains, and the list goes on. if someone can not solder, perhaps they should be sitting down with a pile of 3" lengths of tinned copper wire and solder together wire cubes until they can solder correctly. then progress on to soldering wire links onto veroboard until they reach an acceptable standard of skill. by 'skipping over' the basic skills for any pursuit, one ends up either severely limited at the other end, or, in the case of mountain climbing, rather dead. it is unfortunate that there is no element of fatality involved in playing with microcontrollers. just my opinion, rob :-) |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3816 |
Well I know what you mean but arithmetic is a small and rather unimportant part of mathematics. I do think people ought to learn some, but only some, arithmetic. Far more worrying to me is that many people teaching maths have no qualifications in it beyond maybe a minimal level. John |
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| robert.rozee Guru Joined: 31/12/2012 Location: New ZealandPosts: 2350 |
my soul just died a little bit more rob :-( |
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| hitsware Guru Joined: 23/11/2012 Location: United StatesPosts: 535 |
I can solder just as good as I want, but have never done SMD. So thru-hole would suit me better. (and I doubt I'm alone with that sentiment) |
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| WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2817 |
From the comments above I think it best to offer three alternatives: 1: PIC + thru hole cap (Beginners 28-pin MicroMite): suitable for breadboard 2: PIC + unsoldered SMD cap (Basic 28-pin MicroMite Kit): for people that want to say they 'built' a MicroMite 3: PIC + soldered SMD cap (Basic 28-pin MicroMite Module): nice compact DIP for breadboard or embedding We can then see which one appeals to the public the most . . . . For everything Micromite visit micromite.org Direct Email: whitewizzard@micromite.o |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
PLEASE don't let that stop you from the wonderful world of SMD. I too was exactly the same, and for many years avoided anything that involved SMD, but they are really not that bad to hand-solder, if you have the right technique. EVBlog does some great videos, and the presenter is a bit hyperactive, but he makes good points, so if you want to see how easy SMD really can be with a little practise, then have a look at his videos here, here, and also here. You DO need to practise first, before you try to solder a real one you want to use, but there are plenty of SMD practise kits like this one on the likes of eBay for only five bucks... Smoke makes things work. When the smoke gets out, it stops! |
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