I'm on holiday, but development continues!
New changes in R2:
- The final amplifiers in the output stage for the sine signal will now be the THS3001 and the THS3095 with gains of 2.5 and 2, respectively.
- The output parameters will be written to the EEPROM when entered and loaded next time the device is booted.
- The load disconnect switches will also feed two ADC pins on the ATmega328. When the load is disconnected, all circuitry that is not needed for the disabled channel is powered down to improve battery life. If both outputs are disconnected, the analog power rails will be shut down, drastically decreasing the load on the battery.
- The AD9850 itself will be driven by an ATtiny2313A in a parallel configuration. The ATtiny2313A will only drive the AD9850 (and nothing else), which will enable a maximum of slightly over 9.5 million frequency updates per second when in frequency sweep mode. It will be programmed over I2C and this will only be possible when the interrupt pin is pulled high.
- The two MCUs will probably be programmed with Atmel Studio (free software provided by Atmel) rather than Arduino to allow me to reduce the firmware size (and increase the speed of execution). I haven't decided whether to do this with both of them, but I will definitely do it for the AD9850 controller as it will improve its speed. I will still publish the source and the hex files so you can modify it!