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Here is a few photos of the "laser show controller:D and my 1980s scan head ! AtMega328, DAC and OLED display Dusty G120d scanners - blanking scanner below - no easy peasy TTL blanking control those days:) GM20 colour changer - Z blanking beam path - a right PITA to keep aligned Hope...

Totally agree BB, I think even with a look up table, the 328 won't have enough grunt. At the moment, I'm just outputting the points direct from a data table and getting 30 ish Hz with ~500 points. I think to get a decent graphic, the show guys use a minimum of 700 points (?) which puts the 328...

Hi Camvo, That's great :beer: I've been mucking about with PROGMEM. This stores the point data in program memory instead of RAM. So with 32k (-the program) there should be space for a few decent frames. I drawn out a "LASER" logo - it has 492 points, the ATmega can process this at 38hz, which...

Hi MB, I don't want to hijack Camvo's thread any more than I have done, but I'm using a ATmega 328 on a breakout board running at 16Mhz - the SPI clock I think is running about 4Mhz. Camvo has the better route as the Due has the on-board DACs. He'll be able to write the data to these using...

Bionic Badgers comment re: SPI got me thinking and I looked at some SPI DAC and these can be clocked at +30Mhz ! :beer: So I got hold of a AD5623R-5 dac. This little chip has 2, 12bit channels and has a LDAC line so that you can load each channel registers independantly (coz thats the only way...

Hi camvo, You'll need to manipulate the ATmega328 TWI (I2C) registers directly. Have a plough through the Atmel data sheet - heavy going. http://www.atmel.com/Images/Atmel-8271-8-bit-AVR-Microcontroller-ATmega48A-48PA-88A-88PA-168A-168PA-328-328P_datasheet.pdf good luck, it's like climbing Mt...

Hi Camvo, It may be possible to manipulate the port dirctly (not using the Wire lib) or use the TWI hardware on the ATmega328- but that's way above my software capability. I've had a google round to see if anyone else has done something similar needing a high speed I2C but can't find anything...

Increasing the clock rate from 100khz to 400khz will only speed up the data transfer. The delay between sending the X co-ord and Y-co-ord is dependant on how quickly the Wire.lib executes Even if you could increase the I2C serial clock rate to Ghz, the delay would still be the same as the...

;) Hi, That's the problem, The G120d scanners I used (20yrs ago!)had a step response of about 1ms ...I think these are the equivelent of the 50KPS sets now, so even the slower scan sets of 25kps will have a response time way shorter that 10ms. I dont know enough about the modern scan sets /...

I agree, the I2C bus is slow and the wire lib code to drive it even slower. I still think the staircase effect is to do with the delay between sending out the X then the Y co-ordinate. Speeding up the data transfer from 100khz to 400KHZ will help, but you'll still be lumbered with the wire.lib...

Hi Camvo, As you are calculating the x and y co-ords first , then sending the data to the DtoA together, (which is good) the delay must be due to the slow Wire lib. Even with a small number of co-ords you still should get a direct line between your programmed points. As the galvos have a 1 or...

+1 Camvo, REP to you. You might be liminted by the bandwidth of the I2C bus. You need to calculate the number of co-orddinates you can transfer to the D to As... or the tome delay between sending the X and then y co=ordinate - these should be output symiltaniously or you will get a stair case...

Hi Moh, Could be spot size / cutting speed combination....how does the speed you cut at compared to the system that works. Smaller spot and a fast speed will limit the heat build up. A high power density will ensure the cut is vapourised instead of 'melted' Also could be optics causing splash...

If you can configure the display to ensure the viewers can not come into contact or be hit with the beams, then your power options can be higher. For example, laser shows in night clubs run multi watt systems, they are set up to ensure a beam can not enter the crowd. ATB MM

NP, just needed to know for shopping list of parts :thanks: The PCB was delivered today, just 8 days from ordering :-) Thanks Arg

Hi Arg, Does that mean I don't need to install those particular resistors? (are these the ones for the push buttons) :beer: ATB MM

On that thread, I would have at expected to see a "LEGAL DISCLAMER" notice :rolleyes: :crackup:

I'll ask this one again, hopefully Jerry will answer:beer: ATB MM

Interesting to read. I'll throw smething out there about my observation as a bystander. There is lots of talk about the test LPMs being calibrated to national standards, which is good. However, the test method and set up appears to vary. Jerry has a large lens (I think) between the laser and...

I don't need to buy a "device" from Dell to connect my PC to 3rd party RS232 accessories:beer: