What arduino board are you using ?
Can you explain self-trigger ADC ?
What is max sampling speed and how many quatize bits precision do you get ?
Max sampling speed is maximum ADC sampling speed in Free Running Mode - which is 13 ADC clock cycles + 1 for the self-trigger. If you use the max. prescaler (128) you get an ADC clock speed of 125KHz. This makes about 9Ksamples/second. Doubles whenever you divide the prescaler by two (meaning a prescaler of 64 will give you almost 18ksamples/s). See page 254 of ATMEGA datasheet for more details.The current resolution is 8-bit, but can easily be increased to 10-bit, if needed.
Do you plan to make support multiple channels as well? QuoteYes, either interpolating (sample A,B,A,B...) or framed (trigger A, sample 512A, trigger again A, sample 512B). The former scenario is more accurate, but only gives half sample rate, latter has full sample rate but might not work well if your two channels are of different frequencies.Álvaro
Yes, either interpolating (sample A,B,A,B...) or framed (trigger A, sample 512A, trigger again A, sample 512B). The former scenario is more accurate, but only gives half sample rate, latter has full sample rate but might not work well if your two channels are of different frequencies.Álvaro
This is really a good design. It avoids the timing problems of using a serial packet to trigger the acquisition. The FTDI USB/Serial driver has issues with buffering on the chip side (384 bytes), the driver side (64-4K bytes) and when the buffers are flushed to the application ( 1 msec polled).Could you describe the serial protocol a little bit more ? So I can try to interface your Arduino code with a PC Processing oscope program.
That's an excellent interface definition. Looks like you are defining an "Arduino/PC Interface Standard". Do you have a standards review process in mind ?
The packet structure is concise and could be used for many things. How about a src/dest field so that a UI could combine data from several independent sources ? Like multiple boards on different USB/Serial channels.
Why big-endian ? Seems like Serial.write(0xDEAD) is little-endian with AD byte sent first followed by DE. Are the AVR 32-bit or ARM processors big-endian?
What is max ADC clock speed can I set on arduino boards in Free Running-mode and what would be then the associated bit resolution ?
What is best method to download then display the fastest sampled stream to a Macintosh with either a duamilanove board or mega board which i'm using in my projects ?
- free Running-mode ADC totally independent of the way you'll transfer the samples to a computer via USB
- a specific arduino sketch to capture the ADC samples via ISR management so the samples are stored inside arduino local memory
a special fast transfer protocol to send samples from local arduino memory to a computer via USB
miror protocol on the computer able to decode protocol then display nicely on the screen a scope like
I was asking you about high sampling frequency because my project involves tuning non-linear parametric oscillators via arduino control so I need to have a scope view of a phenomae which is periodic. This means I can have have low ADC resolution and high frequency time synchronize many captures then average mean the samples to increase bits precision by software. Please note this would not be feasible if the visualize scope signal is non-peridoic or rapidly changing shape through short time.
Not easy to explain by mail plus i'm not englihs native. I'm using my arduino as special frequency generator to control different PWM outputs connected to mosfet-drivers and other electro-magnetci components,.... On the other hand, i wish to scope monitor specific voltages from my electro-magnetic oscilator device to perform parametric tuning. This means but i don't know if it is feasible: I need to trigger the free-running ADC on the same phase of my oscillator so then, I can integrate in phase & get more scope sample definition.
You can trigger sampling start based on any pin, or you can use the analog comparator for this.
I actually designed this so I can take a look at back-EMF from a motor, driven by two or three half-bridges. I'll let you know my progress.
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