PICNET usb -> relay controller - Page 2

jcdillin · 04-02-2005, 08:51 PM

What speed are those crystals? to save on space and componets I always use crystal resonators. Then you dont need the stablizing caps

kiltjim · 04-02-2005, 09:40 PM

4 mhz. Again, I didn't design the board. Are they just called crystal resonators? Or do they have any other names?

jcdillin · 04-02-2005, 09:46 PM

that is the name i've always known them by, but they are great, just put each pin to the OSC in and out of the pic and the 3rd pin to ground and you are set

Chris31 · 04-02-2005, 10:23 PM

Quote: Originally Posted by kiltjim

4 mhz. Again, I didn't design the board. Are they just called crystal resonators? Or do they have any other names?

Opps sorry, I must have missed that.

From the other thread,

Im testing the relay card as I type. All seems well so far

Got to buy some cable tomorrow to test it alittle bit more, then back to the firmware cleaning up again.

Bootloader is all done, so it should be easy to upgrade/modify the firmware at anytime.

darkciti · 04-02-2005, 11:15 PM

Why do resonators have 3 pins, but crystals only have 2 ?

Is it because they are surface mount?

kiltjim · 04-03-2005, 12:03 AM

I wish I knew these things existed before I ordered everything. I already ordered the whole lot of things to make both the board, and the PIC programmer. I should have all the parts in my hands by Tuesday. And of course, hours after I placed the order, Chris31 comes out with news that he finished the other one. Nuts. Just bad timing I guess.

KyleYankan · 04-03-2005, 12:08 AM

Yeah butno offense to chris - but isn't his costing like $100 to make? You said earlier thats yours was only about $20.

Also, I like the idea of USB. Not alot of newer computers have serial so your idea could come in useful for those computers.

Chris31 · 04-03-2005, 12:32 AM

Why would it be $100?

KyleYankan · 04-03-2005, 12:36 AM

I'm sorry Chris - I was thinking of the wrong thread. That's the price for someone's ECU reader - for if you don't have ODBII.

My fault. I apoligize. I can't wait for either one of these to come out. If one comes out for less than $20 - I'd be buying it that Thursday (payday). :-D

Chris31 · 04-03-2005, 12:47 AM

The most expensive parts are the relays. Theres no way out of that unless you can get them for free. The price and quality of the relay used is down to the individuals. The cost of it can be reduced further by soldering wires directly onto the board, no connectors, no DB9 socket, no IC sockets. Some of the capacitor and input protection circuitry can be removed to reduce the cost for another $1-2. But obviosly those parts was put there for a reason.

For the USB version, yes it will appear someday. It be even cheaper. No need for the MAX232, and those 5 caps. No need for a voltage regulator and no need for that ugly DB9 connector.

The USB version will be SMD, cheaper PCB.

How cheap should it be?

Chris31 · 04-03-2005, 12:53 AM

Hehe ok no problemo, 100 for ECU reader? that is expensive if we are just talking about the parts. If ready built and all I guess they can put any price tag on it.

Less than $20, its possible with one relay yeah

I dont know how much a relay is over there but in maplins they cost about $3 each.

No, Im not selling them, its here for people who wanna built it.

KyleYankan · 04-03-2005, 01:14 AM

In that case I apoligize - I didn't read your whole thread.

I would love to build a circuit such as this, and hook it up. I would love to see some real-world values coming in. The most I've done is enabled the 8 output pins to relays, on my parallel port.

Also - I just read a fair bit of the other post. I am really surprised at the capabilities of that card. I just wonder if it's possible to buy the chips pre-programmed.

kiltjim · 04-03-2005, 11:19 AM

For the $20 price I stated earlier, it is only for the board. And that could probably be a high estimate because that included the parts to build a PIC programmer (I just went off of the total order price). It does not include the relays. I just so happen to have 8 bosch relays from another project I scrapped (poor battlebot...) so I don't have to spend any money on them.

I'm not saying that Chris31/Ricky327's card isn't awesome. Heck, by the looks of it, its gonna be better than mine. I just got anxious I guess. I'll probably end up with both, so I can make the software compatible with either. In fact, if the command structure doesn't change much, Chris's card will come first for the programming.

Saab9-5 · 04-03-2005, 11:39 AM

Quote: Originally Posted by darkciti

Why do resonators have 3 pins, but crystals only have 2 ?

Is it because they are surface mount?

Resonators have three pins because they're made up of a crystal and two capacitors that feed to ground. It doesn't matter whether its surface mount or regular.

Probedude_2000 · 04-04-2005, 11:57 PM

Quote: Originally Posted by Saab9-5

Resonators have three pins because they're made up of a crystal and two capacitors that feed to ground. It doesn't matter whether its surface mount or regular.

And there's resonators without the built in caps and of course are only 2 pin.