Something is pulling RA0 down or it is floating.
Is RA0 connected to R5 and C2?
If connected, check any shorts from C2 to gnd.
If no shorts, C2 might be faulty.
I appreciate you checking to let us know it works but is there any reason it started working? Nobody will laugh at you if it was a dumb mistake - we'll just laugh at our old memories of the time we made the same (or similar) mistake.
If someone helps you, you'll need to also help yourself. Read the link on the Roman black.com site and you will see...
"As the circuit is VERY simple (it's just a PIC and a few parts) I made it on veroboard (stripboard). It is really not worth etching a PCB for this project! A small SMD 5v regulator is soldered to the bottom of the PCB, all the other parts can be seen below; "
So, no, there is no PCB and no need for a PCB if you are making fewer than 5 pieces. If you are making more, it is a very easy board - you could draw it with a felt tip pen.
I want to know whether it uses pic16f628 or pic16f628a?In China,there's only pic16f628a and it is difficult for me to buy a pic16f628 in China.Can it be replaced by pic16f628a?
Thanks.
I want to know whether it uses pic16f628 or pic16f628a?In China,there's only pic16f628a and it is difficult for me to buy a pic16f628 in China.Can it be replaced by pic16f628a?
Thanks.
The project was designed around the 628 - a part that doesn not have an internal oscillator. Roman Black claims either can be used with his hex code. It should work for either '628 or '628A but you will need to rely on an external oscillator since the configuration bits in the hex code are not set for internal oscillator (and 16MHz is needed for Romans design).
Also, here is a long discussion of the project on this site - including a PCB.
Hi, I have done a PIC 16F628 based pico-capacitance meter. I know there are a lot of other designs around but this one is very quick to build as it just uses one IC, the PIC (as it uses the PICs internal comparator as the oscillator). It measures down to 0pF and reads in 0.01pF resolution in...
Hi, I have done a PIC 16F628 based pico-capacitance meter. I know there are a lot of other designs around but this one is very quick to build as it just uses one IC, the PIC (as it uses the PICs internal comparator as the oscillator). It measures down to 0pF and reads in 0.01pF resolution in...
The project was designed around the 628 - a part that doesn not have an internal oscillator. Roman Black claims either can be used with his hex code. It should work for either '628 or '628A but you will need to rely on an external oscillator since the configuration bits in the hex code are not set for internal oscillator (and 16MHz is needed for Romans design).
Also, here is a long discussion of the project on this site - including a PCB.
Hi, I have done a PIC 16F628 based pico-capacitance meter. I know there are a lot of other designs around but this one is very quick to build as it just uses one IC, the PIC (as it uses the PICs internal comparator as the oscillator). It measures down to 0pF and reads in 0.01pF resolution in...
I have another question.Why does the circuit given by the official website seem simpler than the component list given by the website selling kits?The list is blow:
But there aren't so many components in the offical circuit.Which circuit should I look at?Thanks a lot.
Also,there are two Trimmer Potentiometers in the list but there are only one in the offical circuit and they have different models.Are they different versions?Thanks.
Second Edition of Roman Black High Resolution Capacitance Meter. Required solder skill for assembling and testing. Now it has new PCB design, On/Off power switch, trimmer for calibration and easy LCD installation. The kit include LCD that can operate without backlight to improve battery life...