audioguru said:Hi Indecided,
Don't convert the speed signal's pulses to variable DC, use the pulses to clock a counter IC that feeds decoder/LED driver ICs.
How does the pulse rate compare with the speed? Hopefully it is 10 or 100 to one, or binary. :lol:
indecided said:Nigel,
can you recommend any websites for learner level tutorials on PICs?
I can figure out the programming bit and all,
but for this particular project no interface details are provided ; unless someone has a copy of the PIC-Agoras issue in EPE (April, May 1997) I am pretty blur on the i/o details, etc... one I/O from hall effect sensor and that's it?
If i wanted to incorporate a series of LED warnings for speed, that would be simply more programming and more serial lines?
Nigel Goodwin said:indecided said:Nigel,
can you recommend any websites for learner level tutorials on PICs?
You could try mine, but they aren't intended as 'idiots' guide (no disrespect intended).
I can figure out the programming bit and all,
but for this particular project no interface details are provided ; unless someone has a copy of the PIC-Agoras issue in EPE (April, May 1997) I am pretty blur on the i/o details, etc... one I/O from hall effect sensor and that's it?
Yes, it just uses a single input from a sensor, with the output to an LCD text module. I have the magazine at home!.
If i wanted to incorporate a series of LED warnings for speed, that would be simply more programming and more serial lines?
Yes, just a bit of programming and use some extra I/O lines (not serial lines).
indecided said:Could you be so kind as to scan a parts list and a schematic of the Agoras in? Or whatever relevant data would be good too
Nigel Goodwin said:indecided said:Could you be so kind as to scan a parts list and a schematic of the Agoras in? Or whatever relevant data would be good too
Took a bit of finding - April 1997!.
Here's the circuit:
indecided said:Anyways, just a few questions since you have the magazine..
1) Judging by the pinout, the LCD in question would be a < 80 char HD44870 if i'm not mistaken?
2) What is the function of IC2 (not shown but visually tied to INT/RB0 on IC3.. Looks like this is part 2 of 2.. any ideas about part 1?
3) the circut looks like it has its own built in programmer... right?
4) what are the functions of the individual modes, as indicated by the switch S4.
5) I'm rather confused by SK1/3, SK1/4, WD1... WD1 looks like a wall wart (adapter) to me (hope WD /= watchdog, hehe) . SK1/3 ? SK1/4 - tied to ground.
6) How much coding will it take to change the LCD output to a BCD decoder output, as I plan to use 3x 7 segment LED displays.. LCDs are unaffordable and backlit ones are simply pricey where I am.. and we don't have "surplus sales".
7) What I wouldn't do for the WHOLE 2 parts of the article
indecided said:MM..the 16c84 is sorta discontinued and I might have problems finding it at RS.
Can i subsitute it with the 16F84A? I believe it has an extra 32 bytes of codespace... looks backwards compatible by any means.. any problems?
Might be useful if my motorola pressure sensors come in time. Then i probably could integrate vacuum reading too... If I have any I/O pins left.
And I believe the 10MHz version of the chip is used and not the 4MHz one?
anyways, was the 2x8 display they used fully utilized? I'd probably be putting in a 2x16 and will prob want to expand their short forms they used..
How does switch s4 operate? with *eight* modes how is the switch operated?
Actually, umm. what sort of a switch is it in the first place?
@eclipsed - doing this for a 13 year old Honda Accord. Here we're not so lucky and we get the lemon carb cars.. so no computer.
indecided said:Yep, I made a couple of calls and confirmed that the 16F628 is indeed affordable..
And as I expected, it's harder to find a 4 bit binary, rotary switch here then a PIC16F628. The main sources are RS/Farnell (Malaysia) and they're asking twice to THRICE the price of the 16F628 for the switch!
Question : What am I exactly lookin for when you mention a binary, rotary switch - are we looking for - a BCD based switch - hence 1,2,4,8?
Can this rotary switch be replaced by any other form of more economical switching without too much code changes? A single pushbutton would be excellent and more modern looking. two I/Os programmed to look for a latch, and then switch modes - not forgetting to loop 0-7 after that.
Such a pain acquiring components at reasonable pricing here.. I'm off to go see if i can find the rotary & a reasonably backlit LCD at a good price.
Nigel Goodwin said:indecided said:Yep, I made a couple of calls and confirmed that the 16F628 is indeed affordable..
And as I expected, it's harder to find a 4 bit binary, rotary switch here then a PIC16F628. The main sources are RS/Farnell (Malaysia) and they're asking twice to THRICE the price of the 16F628 for the switch!
Question : What am I exactly lookin for when you mention a binary, rotary switch - are we looking for - a BCD based switch - hence 1,2,4,8?
Can this rotary switch be replaced by any other form of more economical switching without too much code changes? A single pushbutton would be excellent and more modern looking. two I/Os programmed to look for a latch, and then switch modes - not forgetting to loop 0-7 after that.
Such a pain acquiring components at reasonable pricing here.. I'm off to go see if i can find the rotary & a reasonably backlit LCD at a good price.
You could do it with an eight way switch, and use diodes to create the binary data - it's a good test for you :lol:
Or you could replace it by a smaller switch, and alter the code accordingly - do you really need all the options?.
indecided said:eight way switch and diodes to create binary data? Now i'm confused..
how does eight individual pushbutton switches and a maze of diodes sound like?
Nigel Goodwin said:indecided said:eight way switch and diodes to create binary data? Now i'm confused..
Think pull-up resistors on the four lines, with each switch connection taking different lines to ground via diodes - so for all ones you have no diodes, and the resistors pull all the lines HIGH. For all zeros you have diodes from each line, pulling them all LOW - for values inbetween you simply wire diodes accordingly.
how does eight individual pushbutton switches and a maze of diodes sound like?
In sounds like the switches don't latch 8)
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