Cheap digital pattern generator? - Page 1
Forum section: electronics / testgear

author: nctnico
author_rank: Super Contributor
timestamp: May 30, 2013, 01:02:51 am
content: I'm looking for a (cheap) digital pattern generator. Can anyone recommend a device? Preferably something with adjustable output levels. IMHO the tricky bit of a pattern generator is the software to edit the patterns.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 30, 2013, 08:46:34 am
content: When I was looking recently, I found that there appears to be a gap in the market for a cheap & simple pulse generator - considering how easy & cheap the hardware would be with a cheap FPGA it seems odd that nobody has done one. The cheapest ones from major manufacturers are very old analogue-based designs.Obviously for arbitary patterns the UI becomes more of a challenge, but even for basic pulse functions there appears to be very little out there.

author: Rasz
author_rank: Super Contributor
timestamp: May 30, 2013, 08:52:22 am
content: speed?chinese DX clone will do up to 12MHz on 8 channels

author: Bored@Work
author_rank: Super Contributor
timestamp: May 30, 2013, 09:49:30 am
content: Quote from: mikeselectricstuff on May 30, 2013, 08:46:34 amSeveral ARB waveform generators have digital outputs or add-ons for such outputs. Essentially you get the digital data they use to drive their DAC on separate output pins. Instant n-bit pattern generator at fixed logic level. n depending on the word size of the ARB generator.Examples:The crappy Hantek DDS-3x25Rigol DG-POD-A add-on for some of their ARB function generators.

author: nctnico
author_rank: Super Contributor
timestamp: May 30, 2013, 12:02:06 pm
content: I used to have an ARB generator with digital outputs but it had no real tools for creating digital patterns so all in all it was kind off useless. Ofcourse the hardware is not difficult. I even have started on a pattern generator which worked nicely (I still have the VHDL files somewhere) but the problem is the software. Ultimately it would be nice to create I2C, UART and SPI patterns with a few mouse clicks.

author: Bored@Work
author_rank: Super Contributor
timestamp: May 30, 2013, 12:20:07 pm
content: In such cases I use a scripting language, or for more complex stuff, Matlab (at work) or Octave (at home), to calculate and generate bit patterns. I find that more convenient than having to move a cursor around with a mouse, click myself silly and in the end anyhow have to use the keyboard to type in a value.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 30, 2013, 01:02:13 pm
content: Quote from: Bored@Work on May 30, 2013, 09:49:30 amThe problem is that most ARB gens are limited by memory size, so can't produce pulses with low duty cycles - it's a great shame that Rigol didn't add some simple pulsegen specific modes into their latest low-cost AWG as it would have made it a lot more useful, and cost nothing as it would have just been a few counters in the FPGA.However for simple pulse-only functionality, the basic hardware can be extremely simple and cheap.

author: grenert
author_rank: Frequent Contributor
timestamp: May 30, 2013, 01:39:37 pm
content: I think the Ikalogic Scanalogic 2 will do what you're looking for. The control software is fully functional without the device, so you can check it out.www.ikalogic.com/ikalogic-products/scanalogic-2/Note that there are two versions of the software (Scanastudio). The newer version does not yet include suppoort for the Scanalogic 2, so you want the older version (still available on the website).

author: nctnico
author_rank: Super Contributor
timestamp: May 30, 2013, 06:14:51 pm
content: I looked at it but editing signals is very cumbersome and it can only generate UART data. Secondly you'd want to allow an output to become high impedance (for reading something from an I2C device).