PugazhM

Dear Carlos,If you use the SPI based MAX7219, please try the following sketch, and confirm display is working fine.https://www.instructables.com/id/Arduino-Laser-Obstacle-Detection-Proximity-Sensing/ .And connect the D4,D2,D3, VCC, and Ground to the MAX7219 board.This experiment is based on real time hardware. And worked fine.If the display works fine, then rest will work as expected. Send me any JPG image of your work, analysing further. Kind regardsPugazh

Any 3.3 volt zener diode can supply the reference volt to ADC.Also you can try with " ZXRE330AV-A" from mouser. Its a fixed 3.3 volt voltage reference.

I am not sure. Its available at http://www.tinylcd.com/tiny149/

Yes It will work. Its a serial SPI LCD.

Thanks Zeevon. I used simulator. That's Why I could not come across the problem.

Thanks Zeevon. I used simulator. That's Why I could not come across the problem.

Please below the link for LCDhttp://www.tinylcd.com/tiny149/product.php?id_product=61

Hi Dan.CS (Chip select) and LOAD, both are same. Try connecting as given. It should work.

Please find in attached html pagehttp://www.waveshare.com/laser-sensor.htm

Thanks diy_bloke

Proteus is a simulation tool, and com0com is virtual serial port software. For communicating from simulator to virtual com (com0com) port, Proteus provides the COMPIM. Anyway with out the com0com and COMPIM, if one program the Arduino with provided software, and connect the serial monitor tool via USB, the Arduino will send / receive the packets. Its a test program, so fixed baud rate of 9600 is chosen. But the Arduino can be programmed between 2400 to 115200 bits per second.