Sigrok and a “cheap” Saleae clone can save your life (I meant your time)

An affordable, inexpensive and “cheap” Saleae clone could save your day (really).

You could find it for less than U$ 10:
http://www.electrodragon.com/product/saleae-usb-logic-analyzer-24m-8-channel/

I was implementing a NuttX driver for BMP180 over I2C, but was failing to get it working and it was difficult to discover what was going on.

I decided to test my cheap Saleae clone for the first time. The Sigrok tool installation from source code is explained here:

http://marcusjenkins.com/linux/saleae-logic-analyser-clone-with-ubuntu/

Then compared my driver command:

bad_i2c_command

against Adrafruit BMP085/BMP180 commands:

good_i2c

Imediately I noticed I forgot to write the register address that I need to read before issuing the read command.

Just an I2C_WRITE before a I2C_READ fixed the issue!

Related: How to use sigrok to measure real-time signal latency http://blog.savoirfairelinux.com/en/2014/logic-analyzer-visualize-latency-with-sigrok-and-matplotlib/

Update: You need to copy the firmware to Sigrok work:

cp fx2lafw-saleae-logic.fw /usr/local/share/sigrok-firmware/fx2lafw-saleae-logic.fw

I got the firmware from sigrok-firmware-fx2lafw-bin-0.1.3.tar.gz

5 thoughts on “Sigrok and a “cheap” Saleae clone can save your life (I meant your time)

  1. To me, using a clone is unethical (and illegal?). Saleae does a great job developing hardware and software, and using clones like this might stop innovation. Just my $1.

    1. Hi Erich, I agree with you in part, but the equation is a little bit more complex.

      If you receive about U$5000/month then paying about U$200 for a logic analyser is fine. But if you live in a country where you receive less than U$300/month then paying U$200 + 60% import tax + U$40.00 shipping for a logic analyser is equivalent to you paying more than your month salary just for a logic analyser. (only to put it in a scale).

      Saleae is doing a great work and I’m glad to them for developing software for Windows, Linux and Mac. But instead of buying their “Apple-like design” logic analyser I bought an OpenBench (http://dangerousprototypes.com/docs/Open_Bench_Logic_Sniffer) because they are developing open-source software/hardware. As you can see OpenBench doesn’t have a case, there is no design at all, but it works better than Saleae clones (maybe even better than original Saleae).

      Buying a clone of an old product (released more than 5 years ago) will not stop innovation, what stops innovation is the company not investing their exorbitant profits in new products.

  2. Yes, I get your point. And actually I had a similar discussion a while back with students who bought clones. They did not earn $300/month, they were in the $500 range. I agree that $200 in such an environment is a lot, especially if doing it as a hobby. If it is for business, that might shift it a bit. Saleae got a lot of feedback on the price point, that’s why I think they came out with a $108 version: It is still $100, but you get a good product. The OpenBench one is then the right way to go, as this is open source and not a clone. I do not own an OpenBench one, but I hear goo things about it, especially for Linux users. And if that $50 are still too high, then it is still possible to use a FRDM-KL25Z board (for $15) as a logic analyzer (http://mcuoneclipse.com/2014/06/19/updated-freedom-board-logic-analyzer-with-dma/). It won’t work for high speed, it is not as good I think as the OpenBench one, but still good enough for many tasks.
    I don’t agree that if the clone is for an older product: to my feeling, these clones nearly have killed Saleae, and they did not come out with a new product for a long time. So buying clones regardless how old the design is will cause some damage. Again: if the price point is too high, there are plenty of alternatives to choose from. But I don’t want to give my money to pirates. I have no problem with companies going out of business because they are not competive. If a company is out of business, then making clones might be a different thing. So as long Saleae is producing and sellign Logic Analyzer, I will not consider clones.
    I hope that makes sense.

  3. Hi Erich,
    I completely agree with your discuss.
    Very nice your logic analyzer with DMA. Did you test it with Sigrok?
    I think this Saleae for $109 is only 4 inputs. It should be the original Logic with 8 inputs.
    It should be better if Saleae creates a student version like J-Link does, I bought the J-Link EDU although I prefer to use OpenOCD when microcontroller is supported or when I can adapt it to work, as for Kinetis KL25Z.

  4. I have not used Sigrok, I only have used OLS (http://www.lxtreme.nl/ols/) with it.
    Yes, that $109 has 4 inputs, but this should be enough for most applications.
    I have very mixed feelings about OpenOCD: it has not worked well for me in the past (v0.8.0), but I had not tried the latest v0.9.0 yet.

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