freeSim hardware: development log

[ababkin]

Hi all. I decided to keep my HW log in this thread for myself and for whoever else cares.
This log is intended to reflect my progress projected over the timeline.
This thread is still the main freeSim HW thread, posts in which will be updated as required.

[ababkin]

Pretty much decided to use the following dev board for the freeSim (based on the advice of a local friend who will stay anonymous for now):

http://www.silabs.com/tgwWebApp/public/ ... F120DK.htm

So initial idea of using parts or whole of MS hardware was dropped.


Despite being 8bit, this MCU (C5081F120) has many features appealing to freeSim like 100MIPS, SPI interface and internal DACs (2 12bit channels).
The dev kit is only $99 (comes with debugger, cables, software, etc) and bare board is $50.
The expantion proto-board (with extra SRAM that i may or may not need) is $35

The two DAC channels can be used for analog outputs that need to be precise (12bit) and/or responsive. I suspect those will be the MAP(MAF) and WBO outputs.
For others, like IAT, CLT, i plan to use digipots and for TPS, a digipot with bias resistors or sample-and-hold circuit (analog (de)multiplexer) to increase the amount of DAC channels.

there is however not much available in DIP packages on digikey, but another friend of mine suggested that digikey should also have some nifty adaptor boards with pads for SOIC type of packaged chips.

[Tony]

there is however not much available in DIP packages on digikey, but another friend of mine suggested that digikey should also have some nifty adaptor boards with pads for SOIC type of packaged chips.

Yes they do they are called surf boards.

[ababkin]

Yes they do they are called surf boards.

wow, i totally didn't expect a reply
i really appreciate any advice or info anyone has to offer in regards to this, i am only a newb in the whole digital hardware thing. Come from very high level and theoretical Math/ComputerScience camp you see, so, naturally, no hands-on experience.
Love soldering things to death tho, so i am sure i'll catch up

Will also need to do some voltage conversion to 0-5V range (for MAP, TPS, WBO, etc signals), so i may need some experienced help there.

[Tony]

LOL i dont know how much help i could be but the surf boards are on page 2167 of the Digi key catalog.

The thing about the surfboards is they only hold the single component so if it needs other components for it to work they would either have to be on the main through hole board or on a daughter card could be made that would hold all the components on the card and plug into a header on the main through hole board sorta like the MS2 card plugs into the main MS board.

If you made your own daughter card to hold the components you would probably save money going that route Vrs. buying the surf boards of course you would only save money if you needed quite a few of them vrs. making one board..

How many pins dose the component have that you are needing a adapter for and how many components does it need to operate?

[ababkin]

Got 'em, i think these are the ones i need:

http://www.capitaladvanced.com/9000ser.htm

but damn, $4-7 for each one of those is kinda steep

[Tony]

Yeah thats why i say if you need quite a few of them it would be cheaper to just layout whatever you need as a daughter card and make 20-100 of them up if your prototyping though its not bad if you need more than a couple we can make our own all i would need is a schematic of what you need and its pretty simple from there.

[ababkin]

Thanks again Tony, at this point however, i myself am not sure about what i will need.
Once i have a working prototype, i will take you up on this so others can assmeble the sim cheaper/better.

Please do enlighten me on the process of PCB making though. So you have a service you use for this? Do you create your own designs (i think it's called gerber file)? Is there a thread about it already on this forum?

Cheers

[Fred]

google laser printing to glossy paper and or transparency, its an easy quick way to do it at home. You just print, iron the art onto the copper, and dissolve the excess. I think he uses a service. If you want nice quality, you need to do that. Home boards aren't always the best...

Admin.

[Tony]

Thanks again Tony, at this point however, i myself am not sure about what i will need.
Once i have a working prototype, i will take you up on this so others can assmeble the sim cheaper/better.

Please do enlighten me on the process of PCB making though. So you have a service you use for this? Do you create your own designs (i think it's called gerber file)? Is there a thread about it already on this forum?

Cheers

Hey no problem yeah if your prototyping you can buy the surf board or like Bert says you could try the "toner transfer method" and there ware some other methods too to make one at home .

Search for toner transfer on you tube there is a video of some guys making a board on there using the toner transfer method.


Yes i have made a few boards using a PCB software its no big deal depending on the size i can make you one up pretty quick but this would only be worth while for quantities of 10 or more.