Working with V4 Separate Dev Boards

Order of operations for testing/debuggin V4 Miniscope electronics when using separate rigid and flex boards.

1. Visually inspect PCBs, positioning of components, and solder joints. Pay particular attention to the alignment of the PYTHON480 and the solder on the flexPC solder pads.
2. Check for continuity between the GND on the serializer PCB with the GND on the LED/EWL PCB. This can be done using a multimeter in continuity mode and touching the outer shield of the coax cable and the open pad at the bottom of the LED/EWL PCB.
3. Check for continuity between the 1.8V supply on the serializer PCB and the 1.8V pad on the MCU PCB. TODO: Add picture for all continuity tests
4. Check for continuity between the 3.3V supply on the serializer PCB and the 3.3V flexPC pad on the LED/EWL PCB.
5. Move onto the following steps only if all 3 above continuity tests passed inspection.
6. Program the MCU. Make sure Atmel Studio says the MCU was programmed successfully.
7. Power up the system and check to make sure both the blue excitation LED and red status LED are both on. The MCU contols both of these and both should default to the on state if the MCU was programmed successfully, if the flexPC connection are correct, and if power is being supplied correctly. If these LED do not turn on you need to check the flexPC solder connections since this is the likely source of the issue. Do not move on until both LED turn on on power up.
8. Power up the system again and check the pixel clock output of the PYTHON480. This should be 16.6MHz or ~66MHz. If the pixel clock is present it means the MCU can successfully configure the PYTHON480 over SPI. (The following is not implemented yet. We will add some MCU code that first polls the PYTHON480 for it's part ID. This will test the SPI connection for you. If this polling fails we will have the red LED blink)
9. Make sure the pixel clock, LV, and FV signals are reaching the serializer PCB.
10. Move over to the DAQ and check to see if the pixel clock, LV, and FV signals are being correctly produced on the DAQ. If the pixel clock sits at around 50MHz this likely means you are using the wrong serializer or that the serializer is not receiving the pixel clock from the PYTHON480.
11. At this point, everything should be working well enough for the computer to connect to the Miniscope electronics. Connect using the Minsicope DAQ software and test the adjustment of the excitation LED intensity and the EWL focal plane adjustment.
12. If the EWL is not changing focal planes make sure the flexPC connecting to the EWL is not shorted across its solder pads. Make sure the gap between the EWL solder pads on the LED/EWL PCB is clean and not heating up. Make sure the EWL flexPC is positioned correctly to make proper contact with the EWL.
13. Check for overheating of the PCBs. The serializer PCB, especially the large inductor on the PCB,will be hot to the touch. It should be so hot that you cannot hold you finger on it though. The PYTHON480 PCB should also be warm/hot to the touch but cooler than the serializer PCB. The MCU PCB should be at room temperature. The LED/EWL PCB should be reasonably cool when not using high LED power. The EWL driver and solder pads sometimes heat up but this is usually due to flux residue remaining between the EWL flexPC sodler pads. If this is the case remove the flexPC, clean the around and between the solder pads, then resolder the flexPC.
14. At this point everything should be tested and functional!