I work with the PSC100 to solve electronic problems in the automotive field.
I’am a teacher in a mechanical school in france.
I try to find a simple way (as cheap as possible) to observe all the needed signals of the automotive diagnosis. My aim is to allow students to have their own “diagnosis tool”.
Pc oscilloscope are really too powerful and so too expensive.
What we really need is a PSC100 like but with a time step of 0,5 ms (as far has i know, the PSC100 is 10 ms).
So I got 3 questions :
1 - Can I use the DLL routine to “check” 2000 times a second the values of the PSC100 inputs ? (I don’t think so but …)
2 - Can I change the “software” in the PIC to increase the time resolution ?
3 - Or, no way, with the actual electronique circuit, 10 ms is the minimum time step value.
That for reading me.
Really sorry for my english of french engineers :S …
So if I understand you are looking for a small, inexpensive device, connected to a computer, that can sample several signals at 2000 samples/sec - is that correct? What are the other key data? E.g.
how many channels need to be monitored?
what’s the voltage range? (0 to 5 Volts, or other?)
triggered on one of the channels (or separate trigger channel) or free-running?
necessary record length (how many samples)?
always 2000 samples/sec, or also faster/slower?
how many of those devices would you need, and what would be the budget for that? (you say the PC based scopes are expensive, so I assume less than that)
real-time (scope-like) display, or simple capture to text file?
I may be able to help you find what you need. If you are interested, contact me at gwen.and.wolfgang[at]sbcglobal.net (replace the [at] with the @ sign!)
Hello vrince.
Sorry but the sampling speed of the PCS10 can’t be increased from the 10 ms rate. The speed is based on the USB standard. The polling frequency in the low speed USB communication, that the PIC in the PCS10 uses, is fixed and can’t be increased.
Sorry that no solution to your problem at the moment…
You wrote “PCS100”… I think you mean PCS10 anyhow…
The sample rate you requested may be possible by using a full speed USB PIC (e.g. PIC18F2550).
It is complicated to realise: You have to develop new PIC firmware and new PC software for the communication.
If you anyhow want to try, then change the IC1 to PIC18F2550, change X1 to 4MHz and remove R1. Then you need PIC programmer (e.g. ICD 2), MPLAB development software and the free C-compiler from Microchip.
Then download Microchip Custom Driver package to start…
Seems you are just between chairs - 1 ks/s is faster than most inexpensive data loggers can achieve, but pretty slow for a scope (which is much more expensive). If you are interested - and provided Velleman can’t provide what you need, since I don’t want to steal their business - I could put a simple but usable solution together within a few days with the following performance:
1 kSamples/sec on 2 channels, resolution 10 bits (could also do 4 channels but with slower acquisition rate)
real-time capture,
adjustable voltage range if necessary
connection to PC through standard RS-232 serial port
PC waveform viewer software with trigger on channel 1 or 2, pre-trigger display, or continuous capture into a file.
All that should cost less than US$50 per unit, including parts, a printed circuit board, and an enclosure. This assumes a sufficient number (at least 10) of the unit is built. I would do this for the fun of it so I’d do the development and manufacturing at material cost, and not charge for my time.
By the way, feel free to write me in French if that is easier for you.
