Which loads you have on?#20 Updated with 12V LI-ON battery.
Hi J,Make a simple test program to blink the LEDs and make all other ports as inputs ( might the default ?) and measure the 12V/3.3V
Hi J,You can cut the trace from 3.3V to PIC to see what happens.
The frequency of the ripple voltage is near 125kHz.
Might be the SPI clock, 8MHz/64 ?
Hi J,You can cut the trace from 3.3V to PIC to see what happens.
The frequency of the ripple voltage is near 125kHz.
Might be the SPI clock, 8MHz/64 ?
Hi J,Check the 3.3V also after cutting the trace.
GOOD FOR YOU for figuring out calibration!Hi B,
How do I calibrate the probes?
EDIT: Found and did a calibration.
For the images in #10, I stopped the Osc, then it automatically started when I switched ON the voltage.
I don't think mine has the add on, for printing, as there are no ports.
3.5" floppies! You remind me of loading the 16? floppies for Windows 3.1 and looking forward to seeing the paper clip
EDIT: Mine doesn't have the output extension, so no prinint etc
C.
Hi B,GOOD FOR YOU for figuring out calibration!
View attachment 232498
Your "STOP/RUN" button is at the top right- press this and it will freeze the screen. Press it again, and the scope will scan again. You appear to be missing the extension that would allow printing using the HARDCOPY button to RS-232 interface- You might look around and see if you can find one for reasonable price and install it.
Here is a Beginner's Guide I found for your scope- it will help you tremendously:
https://www.physics.queensu.ca/~phys352/BMScope_intro.pdf
Your scope is a fantastic scope- it is fast enough to handle any project you will do. Take good care of it and be careful with it, and it will serve you well. The probes are probably more expensive than the scope itself at this point, so if you only have 2, see if you can obtain a 3rd one as a spare for a reasonable price before the become impossible to find.
Hi S,looks like the power supply oscillation issue will get solution, interesting project.
There is datasheet that discusses input output how to derate and which ceramic capacitors. A ceramic output cap derated = 20uF
https://e2e.ti.com/support/power-ma...tps7a91evm-831-input-output-capacitors-values
If there is concern on the uC board, the input decoupling cap on the input pin uC is important.
Hi E,hi C,
With the digital projects you do, I would get this probe pair , they have *1 and *10 attenuation selection.
E
https://www.ebay.co.uk/itm/2pcs-100...804115?hash=item4b8bba8593:g:rxYAAOSwcftgEjNd
Is the PIC the old one ( faulty )?Hi,
I spoke too soon!
There is now a 100uF polarised electrolytic cap before and after the 3.3V 4431 REG.
The before and after votages show smooth.
After a while the LEDS started errors. The 3.3REG got hot and the VDD PINs are tarnishing, so I pressume hot.
The voltage at the LEDs is app 1V.
All PINs of the PIC show sensible resistance.
What to test? I'll try cutting the PIC VDD first, and see what happens.
C.
by Duane Benson
by Jake Hertz
by Jake Hertz
by Jake Hertz