Designing a basic circuit board

[cat007]

Hey all

I need a simple display circuit board designed that I can hook up to my wideband up to.

Basically it'll have a linear scale of 0-5volts and would to have a 3 segment (to 1 decimal place) display.

Can anyone help me out?

[fivebob]

Why not use something like an Arduino Prototype board.

Cheap (around $US20), good support and heaps of add-ons available like LCD, SD cards etc, you could even turn it into a datalogger if you wanted to

[cat007]

hmmm would be a good idea

but possibly a little too hard/complex

[fivebob]

A lot easier than you might imagine, certainly easier than designing circuits to do the same thing. Chances are someone has already done what you want to do before and it's just a matter of copying their code

[cat007]

A lot easier than you might imagine, certainly easier than designing circuits to do the same thing. Chances are someone has already done what you want to do before and it's just a matter of copying their code

Exactly - was hoping someone on here has already done it

I want it so for example the display would read 09.0 at 1 volt and then 20.0 at 5volts.

[Akane]

You can etch your own board.

http://www.youtube.com/watch?v=tWnfnt2rNO0

From memory of the Bosch LSU 4.2 Datasheet, it's not linear. There's the Rich gas and Lean gas sections and they're curved. :/

Also there is the wideband sensor heater.



I think you're better off buying a controller. I had to.

[cat007]

You can etch your own board.

http://www.youtube.com/watch?v=tWnfnt2rNO0

From memory of the Bosch LSU 4.2 Datasheet, it's not linear. There's the Rich gas and Lean gas sections and they're curved. :/

Also there is the wideband sensor heater.



I think you're better off buying a controller. I had to.

I'm using an Innovate LC1 which has programmable outputs so you can hook them up to ECU inputs or similar.

http://www.innovatemotorsports.com/supp ... Analog.pdf

[sergei]

You can use AVR/PIC hookit up straight to 2x LED 7seg. display (no drive circuit needed) and use ADC inputs for your input. will only need 5V regulator, couple of capacitors, 1 uC, and bunch of resistors.
You can program a map/table of the values into it to follow any curve you want.


Only problems are
1) assembling it (beginner to intermediate soldering skills/board making)
2) programming it (intermediate C or your language of choice, and lots of RTFM on the uC).

all under $20, if you have necessary tools.

[cat007]

You can use AVR/PIC hookit up straight to 2x LED 7seg. display (no drive circuit needed) and use ADC inputs for your input. will only need 5V regulator, couple of capacitors, 1 uC, and bunch of resistors.
You can program a map/table of the values into it to follow any curve you want.


Only problems are
1) assembling it (beginner to intermediate soldering skills/board making)
2) programming it (intermediate C or your language of choice, and lots of RTFM on the uC).

Thanks for that sergei!

I'd pay for someone to do this as long as it wasn't going to cost the earth!

I can solder find and have made all sorts of things in my time but I'm really a bit of a novice when it comes to designing electronics....

[sergei]

You can use AVR/PIC hookit up straight to 2x LED 7seg. display (no drive circuit needed) and use ADC inputs for your input. will only need 5V regulator, couple of capacitors, 1 uC, and bunch of resistors.
You can program a map/table of the values into it to follow any curve you want.


Only problems are
1) assembling it (beginner to intermediate soldering skills/board making)
2) programming it (intermediate C or your language of choice, and lots of RTFM on the uC).

Thanks for that sergei!

I'd pay for someone to do this as long as it wasn't going to cost the earth!

I can solder find and have made all sorts of things in my time but I'm really a bit of a novice when it comes to designing electronics....

here http://www.avrfreaks.net/ is good place to start.
they even have articles for n00bs.
Putting hardware together will be easy: basically you have one 14pin chip, one 3pin regulator, couple of capacitors, a few resistors and whole bunch of interconnects.
Hardest bit is actually writing firmware. The good thing that AVRs come with easily configurable ADC (your input) and since your voltage range is 0 to 5V there is no need for extra hardware (like opamps) to buffer the input.

To make ADC on, is just matter of setting couple of registers, and from there you can make a while (1) {} loop that that looks up the values on your table (that defines the "curve"), interpolates them, and decodes them into 7led output. Setting output is very easy, again you just write to output register (which in binary represent each pin). .

[fivebob]

here http://www.avrfreaks.net/ is good place to start.
they even have articles for n00bs.
Putting hardware together will be easy: basically you have one 14pin chip, one 3pin regulator, couple of capacitors, a few resistors and whole bunch of interconnects.
Hardest bit is actually writing firmware. The good thing that AVRs come with easily configurable ADC (your input) and since your voltage range is 0 to 5V there is no need for extra hardware (like opamps) to buffer the input.

To make ADC on, is just matter of setting couple of registers, and from there you can make a while (1) {} loop that that looks up the values on your table (that defines the "curve"), interpolates them, and decodes them into 7led output. Setting output is very easy, again you just write to output register (which in binary represent each pin). .

Or buy a development board with bootloader and software libraries and bypass all the hard stuff.

FYI it takes less than 10 lines of code to do what you want to using a serial LED/LCD for display. Programming without the libraries etc would take closer to 100 lines

[sergei]

here http://www.avrfreaks.net/ is good place to start.
they even have articles for n00bs.
Putting hardware together will be easy: basically you have one 14pin chip, one 3pin regulator, couple of capacitors, a few resistors and whole bunch of interconnects.
Hardest bit is actually writing firmware. The good thing that AVRs come with easily configurable ADC (your input) and since your voltage range is 0 to 5V there is no need for extra hardware (like opamps) to buffer the input.

To make ADC on, is just matter of setting couple of registers, and from there you can make a while (1) {} loop that that looks up the values on your table (that defines the "curve"), interpolates them, and decodes them into 7led output. Setting output is very easy, again you just write to output register (which in binary represent each pin). .

Or buy a development board with bootloader and software libraries and bypass all the hard stuff.

FYI it takes less than 10 lines of code to do what you want to using a serial LED/LCD for display. Programming without the libraries etc would take closer to 100 lines

I agree with that. While serial LED/LCD are a lot awesomer they are much more expensive then 2x basic 7segment LEDs.

I have an AVR development board and usb->JTAG programmer.. I haven't used it in a few years though .
I also have various LCD displays (2x16char and 128x64 pixel), and with libs they are definitely easy to program. It just takes a lot of RTFM. While it is all fun, but it becomes beyond the scope of the task as these things add up a lot of $$$, for 1 time use.

[cat007]

Thank you all for your input.

I'm really useless at reading code in any form - let a lone writing it. Not sure why but my brain just doesn't like it lol

I'll have a good look at the links you've provided over the next few days and see if I can wrap my head around it

Thanks again

Hunt

[fivebob]

While serial LED/LCD are a lot awesomer they are much more expensive then 2x basic 7segment LEDs.

16x 2 Serial LCDs can be had for less than $US15, and 4 digit serial LEDs from $US8-$12. More expensive than the basic display but they save a fair bit of time if you're not that good at coding

I'm really useless at reading code in any form - let a lone writing it. Not sure why but my brain just doesn't like it lol

Like I said with a serial display there's not much code to write, I could do it in about 5 mins if all you want it to do is take a linear 0-5v signal and display it as an AFR reading on a LCD, LED might take a little bit longer.

[Akane]

Ahh I see what you mean now, you have the controller but not the display, that's the problem with the LC-1, it's a low cost controller that is designed only to be hooked up to a laptop or a standalone's 0-5v input. I still think saving up for the gauge kit for LC-1 will be a lot more hassle-free. Or even just buy a cheapo laptop for it.

I have a 20x4 board here complete with USB. From crystalfontz. Not exactly what you're looking for though.

I've bought a 20x2 before from the webz a long time ago, serial jobbie, but not cheap on freight.

Not exactly hard to program for the resident geek.

Also have a basic stamp 2, but sergei's AVR might be more suitable for the job. I think AVR has Analog/digital converter built in which what you'll need to convert that 0-5v into something that can be used on the board?

[cat007]

Except the gauge kit for the LC1 is like $300 which is ridiculous!

[cat007]

Except the gauge kit for the LC1 is like $300 which is ridiculous!

sorry - make that $450!!!!! LMFAO

[Guss]

http://www.europerformance.co.nz/product_info.php?products_id=62 thats probably the XD16 gauge which is programmable to all the innovate products.
standalone AFR gauges 'only' $170
depends what you want it for - tuning or as a gauge to occasionally check ?

[cat007]

http://www.europerformance.co.nz/product_info.php?products_id=62 thats probably the XD16 gauge which is programmable to all the innovate products.
standalone AFR gauges 'only' $170
depends what you want it for - tuning or as a gauge to occasionally check ?

I'm not wanting it for tuning. Really only wanting it so I can look at the afr's every now and then

[fivebob]

1 x Arduino Prototype Board $US18.99
1 x 16x2 Serial LCD $US14.99
1 x Sensor Shield $US6.99 - not really necessary, just make it easier to wire up.

Postage $US11.00
Total $US51.99
~$NZ75
Add a box to house it, a couple of resistors and some wire should cost under $90.