TI launchpad

[William Gaatjes]

Great idea . :thumbsup:

I have the same thing in mind for a few months now.
I was planning to use the sam7s256 for it but it has a limitation with the dma.

As such i postponed the idea until the i have a cortex M3 like the sam3s or another cortex m3 mcu with an external bus.

I had this ic in mind as time base for an scope and or function generator : AD9833 (maybe even 2 at once)

http://www.analog.com/en/rfif-components/direct-digital-synthesis-dds/ad9833/products/product.html

Digitally Programmable Frequency and Phase
20 mW Power Consumption at 3 V
0 MHz to 12.5 MHz Output Frequency Range
28-Bit Resolution (0.1 Hz @ 25 MHz Ref Clock)
Sinusoidal/Triangular/Square Wave Outputs
2.3 V to 5.5 V Power Supply

This ADC
http://www.nxp.com/documents/data_sheet/ADC0804S030_040_050.pdf

and dualport ram.

That should be able to do some quick sampling while having lot's of features on the side. And a realtime sampling configuration, and i hope to do some 30 hz refreshing rate at least.

Drive an LCD over the SPI with dma. At least that is the plan.

 

[William Gaatjes]

I found an version better suited to my near future needs :

I am thinking of using this ic as a timebase for my portable oscilloscope.
The AD9834 goes up to 37,5 MHz.

http://www.analog.com/en/rfif-components/direct-digital-synthesis-dds/ad9834/products/product.html


I will then use an AD9833 as a function generator. Afcourse some opamps need to be added to allow amplitude control.

And when the triangle output is fed to one input of an comparator as for example the ADCMP601 and the output signal of a dac or an integrated pwm signal from the ARM MCU to the other input, an pwm signal can be created with an frequency from 0 to 12,5 Mhz with a duty cycle from 0 to 100 percent.
(Why can the forum not display percent characters ?)

An PWM signal.
An square wave.
An sinus wave.
And an triangle wave.