Redpitaya Forum

Hi guys,

I try to control 2 different lasers at a very fast rate (~1MHz). I need to choose which of the four are on/off for each 1us (laser diodes are capable of toggling at these speeds, that's not a problem). I can control the lasers by just giving a 3.3V-5V signal. Is there a way to do this with Red Pitaya?

I tried some other boards like raspberry pi and arduino but the problem was both their speeds (this shouldn't be a problem for red pitaya) and each transition took different time (going from 01 to 10 takes 1.5us while going from 11 to 00 takes 1.3us).

Thanks!

Hi,

the GPIO pins of the expansion connector are CMOS 3.3 V and easily capable of such rates, as they are driven directly by the FPGA. However, you will have to create your own HDL module within the FPGA fabric to drive them according to your needs.
Of course, they probably won't be able to power your lasers.

Thanks for the reply. Actually I don't need it to drive my lasers, I'll use a transistor which switch on/off the power that goes to the laser. The problem is I don't want to do it with HDL/FPGA. I basically want to give an .csv file to it and the pitaya should outputs digital signals according to that. Is it possible to achieve with built-in Signal Generator app?

The Signal Generator app outputs signals via the onboard 2-channel DAC and not via the GPIO pins. The voltage range of the signals is from -1 V to 1 V. Much less than the 3.3-5 V required by your applications.

If you do not want to do it with FPGA, then Red Pitaya board is not well suitable for this task.