what pic should i use?

[sirvo]

Hello!

I'm developing a kind of onboard's car computer and i need to continually measure 3 analog signals (fuel, oxygen sensor, temp.) and one freq. signal (speed sensor). I would like to show all data in an 20x4 LCD. In your opinion, what pic should i use? Is 16f676 a good choice? Any other?

Thanks in advance.

Sylvio

[mister_e]

676 should do. F88 as well.

[skimask]

Hello!

I'm developing a kind of onboard's car computer and i need to continually measure 3 analog signals (fuel, oxygen sensor, temp.) and one freq. signal (speed sensor). I would like to show all data in an 20x4 LCD. In your opinion, what pic should i use? Is 16f676 a good choice? Any other?

Thanks in advance.

Sylvio

Use the ELM327 from www.elmelectronics.com. It's a PIC18F2550.

[sirvo]

skimask.. i have read stuffs about elm327 but i am not sure about using it.
i know that elm can interface the iso9141 obdII protocol, but, does it send all the info. that I need? For example.. i would like to read the fuel sensor, so, do i need just to send a command and it answers to me the value?

Thanks !

Sylvio

editing... i will read the datasheet.. thanks again

[skimask]

skimask.. i have read stuffs about elm327 but i am not sure about using it.
i know that elm can interface the iso9141 obdII protocol, but, does it send all the info. that I need? For example.. i would like to read the fuel sensor, so, do i need just to send a command and it answers to me the value?

Thanks !

Sylvio

editing... i will read the datasheet.. thanks again

It's all in the datasheet...all the values you could ever want, and a load of those you could never use.

[sirvo]

Hello skimask

I've just read the datasheet. The problem is to decode all the data. Do you know how to do that?

Thanks.

Sylvio

[skimask]

Hello skimask

I've just read the datasheet. The problem is to decode all the data. Do you know how to do that?

Thanks.

Sylvio

Decode what? The ELM327 does it all for you, spits out temperature, voltage, o2 sensor readings, etc. You have to do the research OBD-II and figure out what input values give you which output values. There's literally hundreds of them and I don't have the time to explain them here.

[malc-c]

Ahh... but where's the fun in using a pre-programmed PIC. And Sylvio wouldn't lean much about PBP etc

Sylvio, I've just used a 16F676 in one project that the guys here helped me out with, and I'm sure they would all do the same if you chose to go down this route. The only limitation of using the 16F676 is the pin count. 6 of the 12 I/O pins available will be required for a normal 16X2 LCD in 4 bit mode, and without details on the 20 x 4 LCD you are intending to use, you may find it needs more, which would thus limit the number of pins left for your A/D inputs.