Below are some screenshots of an oscilloscope hooked up to the Viking Macro controller's I2C interface and Right Trigger DAC (digital-to-analog converter). Thought some of the hobbyists would enjoy this. I am playing around with the Link Instruments MSO-19. It has a single-channel oscilloscope and an 8-channel logic analyzer, it cost me $249. I would NOT recommend this product if your goal is to monitor and debug I2C and SPI interface. I will be purchasing a different logic analyzer product in the future to help more with monitoring, analyzing and debugging I2C, SPI and other communications.
As far how does the single-channel oscilloscope work, and how's the software? Again it's ok... for the same price (and now knowing that the logic analyzer is junk on this unit), I would have been better off purchasing one of the competition's two-channel analog scopes in the $150-$300 price range, then spending another $200-$300 or so on a 16-channel logic analyzer with bigger buffer and better SPI/I2C software decoder software. The I2C software decoder bundled with the MSO-19 is total junk and doesn't work for me.
There are som USB MSO (mixed-signal oscilloscopes) in the $600 range that look to accomplish the same thing... honestly I think you are better off saving up your money and buying a decent product. Unless you are doing serious audio analysis or other high-accuracy requirement projects, in which case don't even listen to me as you're going to need to spend thousands on an officially calibrated piece of hardware. Anyway, if you're shopping for USB scopes and logic analyzers to connect to your PC, here they are. Be careful of what you buy depending on your project requirements:
www.microcontrollershop.com (check out the LAP-C-16032 logic analyzer at this shop)
This site above carries a lot of different brands...
www.bitscope.com
www.usbee.com
www.saleae.com
www.linkinstruments.com
www.hobbylab.us
www.poscope.com
www.pctestinstruments.com
www.tech-tools.com
(To be fair, maybe I just don't know how the software works, but I'm not impressed here as I can't even capture three full 'trains' of 9-bits on the I2C before I experience aliasing...)
First screenshot shows quick trigger pulls with rapidfire on... (ignore the colored lines at the bottom, the capture resolution on this particular shot is too poor to properly represent the I2C communication)
[attachment=2:cqjfhzjj]Right Trigger rapidfire with full quick pulls.JPG[/attachment:cqjfhzjj]
Second screenshot shows a very slow trigger pulling...
[attachment=1:cqjfhzjj]Right Trigger rapidfire with slow varying pull.JPG[/attachment:cqjfhzjj]
Third screenshot demonstrates the response time of the DAC on the modcchip. Once the DAC acknowledges the command from the CPU, the output begins to change 7.6 microseconds later. It takes about another 2.1 microseconds for the output to resolve.
[attachment=0:cqjfhzjj]Response time of DAC.JPG[/attachment:cqjfhzjj]
As far how does the single-channel oscilloscope work, and how's the software? Again it's ok... for the same price (and now knowing that the logic analyzer is junk on this unit), I would have been better off purchasing one of the competition's two-channel analog scopes in the $150-$300 price range, then spending another $200-$300 or so on a 16-channel logic analyzer with bigger buffer and better SPI/I2C software decoder software. The I2C software decoder bundled with the MSO-19 is total junk and doesn't work for me.
There are som USB MSO (mixed-signal oscilloscopes) in the $600 range that look to accomplish the same thing... honestly I think you are better off saving up your money and buying a decent product. Unless you are doing serious audio analysis or other high-accuracy requirement projects, in which case don't even listen to me as you're going to need to spend thousands on an officially calibrated piece of hardware. Anyway, if you're shopping for USB scopes and logic analyzers to connect to your PC, here they are. Be careful of what you buy depending on your project requirements:
www.microcontrollershop.com (check out the LAP-C-16032 logic analyzer at this shop)
This site above carries a lot of different brands...
www.bitscope.com
www.usbee.com
www.saleae.com
www.linkinstruments.com
www.hobbylab.us
www.poscope.com
www.pctestinstruments.com
www.tech-tools.com
(To be fair, maybe I just don't know how the software works, but I'm not impressed here as I can't even capture three full 'trains' of 9-bits on the I2C before I experience aliasing...)
First screenshot shows quick trigger pulls with rapidfire on... (ignore the colored lines at the bottom, the capture resolution on this particular shot is too poor to properly represent the I2C communication)
[attachment=2:cqjfhzjj]Right Trigger rapidfire with full quick pulls.JPG[/attachment:cqjfhzjj]
Second screenshot shows a very slow trigger pulling...
[attachment=1:cqjfhzjj]Right Trigger rapidfire with slow varying pull.JPG[/attachment:cqjfhzjj]
Third screenshot demonstrates the response time of the DAC on the modcchip. Once the DAC acknowledges the command from the CPU, the output begins to change 7.6 microseconds later. It takes about another 2.1 microseconds for the output to resolve.
[attachment=0:cqjfhzjj]Response time of DAC.JPG[/attachment:cqjfhzjj]
