Description of operational aspects of the 3D printable Raman Spectrometer Operational Manual Part I

A project log for DAV5 V3.01 Raman Spectrometer

The only thing worth doing, is the thing worth doing right!

David H Haffner SrDavid H Haffner Sr 07/17/2017 at 17:050 Comments


Description of operational aspects of the 3D printable Raman Spectrometer

Operational Manual Part I

I am including this brief explanation for some of the operational aspects of this project so it's functions and interconnectivity is less ambiguious.

There are 2 MCU's that control the units overall functions;

Arduino mega 2560

This was necessary in order to operate the turret grating mount system, by using 3 holographic diffraction gratings of various line resolutions ranging from 1200 ln's to 2400 ln/mm, a wide range of wavelengths can be achieved on the "fly" so to speak, without having to physically open the unit up and change it, who would ever want to do that?

The Mega 2560 was chosen because it is a low cost and efficient MCU with sufficient PWM and digital int pins that fit well with the design of this project.

Second, I could not drive the CCD and MTR control all with the Atmega 1284. (I tried)

Atmega 1284P

This was chosen for good reasons, the ATmega1284P is a low-power CMOS 8-bit microcontroller based on the AVR enhanced RISC architecture by executing powerful instructions in a single clock cycle, the ATmega1284P achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed.

The ATmega1284P provides the following features: 128K bytes of In-System Programmable Flash with Read-While-Write capabilities, 4K bytes EEPROM, 16K bytes SRAM, 32 general purpose I/O lines, 32 general purpose working registers, Real Time Counter (RTC), three flexibleTimer/Counters with compare modes and PWM, 2 USARTs, a byte oriented 2-wire Serial Interface, a 8-channel, 10-bit ADC with optional differential input stage with programmable gain, programmable Watchdog Timer with Internal Oscillator, an SPI serial port, IEEE std. 1149.1 compliant JTAG test interface, also used for accessing the On-chip Debug system and programming and six software selectable power saving modes.

Ok, these are the brains behind the brawn of the system, in the examples below I will illustrate that the LED is not on the PCB, but routed to the front panel PWR indicator LED (yellow,) nor are the pwr plugs required on the PCB's unless you want them there, because there connections are also routed to main power.(UR only saving 0.60 cents per board?) Figure. 1 below

The 4 Indicator LED's to the left, are routed to the LCD control interface panel (illustrated in figure. 2

Both MCU's are routed to main PWR (12vdc 1.5A), as seen in figure. 3

The power supply may look a little odd, (it is a pwr supply from Vonage,) I had an extra one and metered it out and it was exactly 12.13 vdc, pretty darn good, and it has been operating very well for awhile now, so I trust it!

You would be surprised how many plug-in power supplies you can meter out and 99 percent of them are no where near the voltages they claim to be, (so much for the "UL" ratings...Ha ha)

Well, this concludes part I of this operation manual, I am at 95 percent project ready test mode, where the rubber really needs to hit the road...its called data!

The proof will be in the proverbial pudding :)

Part II of the operations manual will be very in depth, because it deals with the optical aspects of the design, and how there are no work around's with the quality of optical equipment used. All this will be discussed in detail in my next posting :)