Field testing modified MPP

[CAS]

I think it would certainly be beneficial to improve the circuit as you point out but my whole purpose in adding the ChipKit to the MPP was to test timings and basically a proof of concept. If I add another integrator, I may as well improve the front end as well. It is then no longer a MPP.
I am currently working on a totally different circuit controlled by a Cortex-M4 chip but am using parts of the MPP to test out the bits as I go. The MPP gives me a known reference where, for example, I can connect a new TX or RX circuit for testing.
As I am looking at direct sampling into the ADC of the processor, I probably wont be playing with the integrator circuits. Although if I have to wait for parts, I might have a go at it. Cant hurt learning a little more.

[Chet]

Hi Cas

Sounds like a good plan. What development board are you using with the Cortex-M4 chip?

Thank you,
Chet

[CAS]

I am using a STM32F411 Discovery board. There are 2 versions - Discovery and Nucleo. While the Nucleo seems to be more popular and there are more examples and help files available, the discovery has an onboard Audio chip as well that eliminates the need for me to build that circuit.
http://www.st.com/web/catalog/tools/...N1848/PF260946

I spent nearly all Sunday getting to grips with how to code the interrupts so they work correctly in conjunction with a uS delay routine.

[6666]

Hi CAS, do you recall when you were testing your machine, did you have to alter the GB pulse width very much ?

[CAS]

Once I set it it was pretty good. Only time I changed the settings was as I moved to different areas and even then I am not sure I really needed to change them too much. I kept trying different things as I went along. One thing I did make note of was to either get pots with stiffer shafts or lock them. Some of the settings were a little sensitive and it was annoying when I bumped the pot and it moved.