02/10/2017 at 01:44 •
Received AD9833 - Direct Digital Synthesizer!
We Have some Reference! Managed to pull ~4.5Mhz on VICHY VC99.
The signal was fed directly to VC99(not terminated), while in audible range it was also powering 64Ω headphones (32Ω+32Ω connected in series)
TODO: adding amplifier and digital pots for AREF and amplified signal attenuation, phase shifting. This will be remotely controllable & programmable DDS. More details later - maybe I should create separate sub-projects?
AD9833: 0 MHz to 12.5 MHz output frequency range; VOUT Maximum 0.65V
VC99: Frequency 10Hz - 60mHz; Input sensitivity: 0.7V
01/27/2017 at 21:38 •
Ordered some samples from EXAR, so exited.
Testing Arduino -> Web socket -> Ethernet shield -> node red - it works, not quite sure on speed.
Ethernet shield I tested is wiznet w5100, (http://www.ebay.co.uk/itm/151915704260) have not tested SD Card
https://www.arduino.cc/en/Main/ArduinoEthernetShield v2 mentions W5500
01/16/2017 at 12:59 •
Ordered DDS AD9833 programmable signal generator(expected to arrive in 15-45 days...)
For digital IO I was thinking 26MHz SPI EXAR XRA1405IG24-F 16-channel I/O Expander. It has 2x8 IO rising/falling interrupts, internal pull-up resistors and more
Please share your thoughts
What would be your ideal ADC? How many bits do you require?
Do you know any fancy or interesting SPI ADCs, DACs 2-8 channel (SAR) maybe simultaneous conversion?