Matrix user forums

Hi martin

Thanks im going to have a good play around in the next couple of days i will keep you posted on what i find and where i go

Cheers bob

hi martin

a quick question, as you have stated the reference resistor at 1.5Meg im guessing i need to fit a 1.5 Meg to test this function also if i were to go back to the original 267.3 ohm resistor likewise again change the ref value from 1.5M to 267.3

regards bob

hi martin a big thanks am i correct in thinking now that the ref resistor is 1.5Meg ?? as theres no reference to the original 267.3 ohm one, plus looking at the ADC macro has confused me a bit. as for local variables is it best practice to use these anyway or just when space is getting short, also t...

Hi martin

Yes exactly that

Cheers bob

hi martin been playing a little again with this and when checking the Meg ohm function nothing happens i connected a 1Meg resistor and it comes up as 0.000 plus the please connect wont work i thought this may be an issue with the 267.3 ohm ref resistor so i placed a 1Meg resistor here and tried to m...

hi martin ive used a decision box in ADC macro above the divider calcs and put if R =0.000 so if no resistance it bypasses the diver blocks, ive then in the main put R=0.000 and it now seems to work, just seen your post so i will try your suggestion as well still need to try the Meg ohm function but...

Hi martin
on start up with no value being measured the display shows 0.000MOhms

Bob

Hi martin big thanks ive one more issue since changing the calc box to divider =0 when no resistance is connected i dont get the please connect come up on the display this did work before i made the change, i tried adding a decision box in the ADC macro with if R=0 this would then bypass the divider...

hi martin

thanks for the reply how do you save the image within flowcode im getting a bmp file which wont let me attach in the forum ??

bob

hi martin
thats fixed it , could i ask how you inserted the png pic please

cheers bob

hi martin just tried your version in hardware the kilohm function seems to be fine however when testing a value of 147,4 ohm for example the display says 14.74 ohms this is the same for any value under 1000 ohms the decimal needs moving to the right one space not tried any Meg ohm values yet, had a ...

hi martin, WOW what youve done is pure art i will try your version in hardware and although my version is without doubt primitive and rough round the edges compared to yours i enjoyed the challenge i set myself but it does start to become consuming once i start, on a day off today i spent 6 hours al...

hi steve thanks for the reply you beat me to it i knew i needed to divide by 1000 but couldnt find the right way to do it ive added my new flowchart for comparison, ive modified the VALUE macro as well as the ADC macro seems to be doing what im after now although i will need to further modify to sho...

Hi all, im having trouble with the decimal point, if the value is under 1000 ohms then all is well however when the value goes above 1000 i get the display showing for example 1013.Kohms (ohms denoted by the 4), if when the value is above 1000 how can i get the decimal point to show 1.013 k or even ...

Hi
Couldnt agree more thanks everyone at matrix for a brilliant product and thanks to other users who help people like myself when we are banging our heads on a brick wall apologies for not adding this in my previous comments

Bob

hi i would also like to mention i too noticed martin (medelec)is matrix staff and over the years martin has helped and guided me as i tried and still do get to grips with flowcode programming and microcontrollers, matrix should be immensely proud of your contributions and about time your officially ...

hi martin, you were bang on, it seems my jumper wires are poor, with single core cut to size i can now place the test resistor anywhere on the bread board away from the input and its bang on however when connecting to the pole of the relay from the input with the test resistor on the NO pin to groun...

hi martin thanks for the reply thats a good point and would make sense as ive noticed different results moving jumpers around and im using small pin ones, where i have not done so so far i will replace all wiring with single core wire cut to length and check the results i will let you know, thanks bob

hi been messing with this again today and noticed that when putting the test resistor directly from the analogue input to ground it reads fine but if a jumper wire is added to the analogue input to the test resistor the readings are off, is there a way to shield the jumper wire from the input to tes...

hi all I've been trying for months to read 3 resistances in the format I've attached i have used 1 analogue input to try to read in turn each resistance ie 1-2, 1-6 and 2-6 with the latter number in each being grounded I've used relays (relays are 5v 370 ohm coil non latching) driven by transistors ...

Hi stefan

I have tried this but it made no difference

Bob

hi all I've made a simple circuit to read a resistance using the ADC function, I'm using a 267 Ohm reference resistor with a 0.1% tolerance, when the test switch SW1 is pressed this operates a 5V relay with a coil resistance of 370 Ohms and 0.2 ohms between pole and NC contact to connect the unknown...

Thanks Martin

Hi Martin
as always thanks for the reply so it's safe to say that the software debounce is just as good as the hardware variants plus with the added bonus of a lower component count

Bob

hi all, my question concerns switch debounce when connecting a switch to a pic micros input, whats the best method for the PIC, ive seen circuits using the cmos 40106 schmitt trigger with a couple of resistors and a cap, or just a switch with a cap and resistors or is the software method better ??, ...