LED display is the main component of flight simulator in providing various visual inputs to insects .Naively speaking; this arena does a perfect job of cheating our little friends that they are in real world environment flying. Actual stimulus environment is simulated to perform experiments from simple behavioral assays up to electrophysiological techniques.
The following detailed technical procedure applies for assembling the LED display system. Sources are listed in reference section.
What do you need?
1. Computer (helps if you have administrator control) to access the electronics
2. Matlab package (version 7.8.0-R2009a works for me) with Panel control codes
(Matlab engine better be started with administrator control each time ,It solves many issues)
4.AVR ISP mkvII programmer
5.AVR studio version 4
6. Main parts (except bottom and top board rest are same for 12 and 16 ring panel system G3):
Main Panel controller board (PCB)
Bottom board (has some control switches)
Toggle switch with lengthy wire for power on/off
2 rs232 DB9 connector cables (one to connect PCB and panels, another to connect COM1 port in PC)
Upper board (mainly for mechanical support)
5V, 10A AC to DC power supply with 5pin DIN out
Compact flash card and card reader
LED panel, consists of 64 small LED”S in 8*8 arrays
Depending on your experiment, more accessories!
Programming main and flash microcontroller in PCB:
- AVR studio version 4 software; once you have downloaded it, install it in the main system directory.
- Connect the AVR programmer USB wire to the computer and 6 pin ends to header labeled “Panel ISP” (J7) in main board (PCB).
- Main board has to be connected with DC power source through 5 PIN DIN .Connect toggle switch to PCB.
- Then click open the AVR studio and choose the programmer at start up.
- Choose the Atmega 128 for programming main microcontroller in the MAIN tab; If the signature matches (Read signature) erase the device and proceed to next step.
- Now move to Fuse tab and check below for settings. If everything is set, click program.
- In the program tab you will find flash and EEPROM program menu. Choose the appropriate mainctrl.hex file and program the flash.
- Next step is to program the compactFlash microcontroller.
- Connect the avr programmer with “ISP J8” in PCB.
- You need to choose Atmega 128 in the MAIN menu as mentioned for main MC, check signature, and if it matches go ahead happily to next step to program.
- You need to choose cfctrl .hex file for programming flash microcontroller. All the files will be available here.
- You only need to program the FLASH not EEPROM.
Programming individual LED panels
As shown in the pictures, place the panel to (Col1 / ISP) of PCB.
- AVR ISP MkII to the 6 pin headers, labeled Panel ISP.
- Make sure you have 9 pin serial cable connections between PC and PCB (J23).
- Now open the AVR studio and choose ATMega168 for the microprocessor in the dropdown menu.(don’t forget to read signature)
- To program the fuses open the fuses tab and program them. Set the options shown in the screenshot below and click Program.
- Program the EEPROM by selecting the program tab and electing the panel.eep file and choose panel.hex to program the flash.
- If you see LED flashing 00 ,you are good to go !
- Final step is to address the individual panels (provide each panel with number/address to run the pattern).
- Type PControl in Matlab commend window and choose address under commands menu and change the panel address appropriately (default 00) for all the LED panels you want to stack. check out the sample codes provided in Panel free list.
- At this point ,insert the memory card into PCB and load pre written pattern files to the memory card by choosing load CF in pattern menu
- Now it’s time to assemble all the addressed panels in the panel ring accordingly.
- Rough schematics: power supply to LED rings and PCB (GND + Null), serial connection between ring -PCB J30 and PC – rs232 ctrl, flash card in PCB and toggle switch attached.(added connections if you want to perform closed loop experiments)
- Once everything is ready you can set pattern id in Pcontrol and play. Here is the memory card I use
- Reiser, M. B., & Dickinson, M. H. (2008). A modular display system for insect behavioral neuroscience. Journal of neuroscience methods, 167(2), 127-39. doi:10.1016/j.jneumeth.2007.07.019
- Parts were obtained from Mettrix Technology Corp.