Testing MPLABX and Open Bench Logic Analyzer (part-2)

The previous post is about the installation, developing and programming of logic analyzer testing circuit with MPLABX. Now, it is time to test with my new OBLS. Connect all input test connectors with PIC PORTB pins and also ground. Power up the circuit.

First, I tested the circuit with oscilloscope to sure the code and circuit are working. Good, output signals are generating. I tested all pins of PIC PORTB. As expected, pin-1 output frequency is twice of pin-2, pin-2 also twice of pin-3 and so on.

There are several of client software to use with OBLS.

I don’t want to use .NET and python. Sigrok is not released yet. RCP client is still initial phase but has some distant features such as frequency and distance measurement.  I also prefer cross platform feature. So, I tested SUMP client and OLS client.

The SUMP client has a installer and installation is straight forward. I like the installer from Gadget factory. There is the original client here but I don’t want to mess with RTTX dependency (used for java serial port support).

For some clients, when you plugin analyzer USB cable to PC, point the driver for “mchpcdc.inf” file. Find in the zip package for “driver” folders and select this file.

http://gadgetforge.gadgetfactory.net/gf/download/frsrelease/154/519/OpenBenchLogicSniffer-2.12b-Setup.exe

The next is OLS client. It is just a zip package and unzip it to required place to install.

http://www.lxtreme.nl/ols/ols-0.9.4-full.zip

– To start measurement, start OLS client

– At menu bar, select  Capture–> Device –> Openbench LogicSniffer.

– At menu bar, select Capture–> Begincapture

– Select Serial port , my PC port is COM12. Leave port speed : 112500 and device : Openbench Logicsniffer.

– You may need to set Acquisition tab for more utilization. Most interested option are Sampling rate and recording size.

– For sampling rate, you can set the highest “200MHz” if you don’t to brother. For rule of thumb, the sampling rate should be twice of measuring signal. ie: if you want to measure 9600 kbps UART output, sampling rate should be 20kHz at least.

– For Recording size, you can check “Automatic” if you don”t brother. For rule of thumb, OBLS support, 24K samples for 8 inputs channel. If you use 16 channel inputs, it will reduced to 12K proportionally. For 24 inputs, it is 8K and so on.

– It is a good idea to check “Noise Filter” to prevent transition spike.

– My test don’t need trigger and leave it. OLS also supports single  trigger or complex trigger mode. For more detailed, here is tutorials in DP site.

http://dangerousprototypes.com/docs/Logic_Sniffer_101

http://dangerousprototypes.com/docs/Logic_Sniffer_102

http://dangerousprototypes.com/docs/Logic_Sniffer_103

– Then click “Capture” to start  capturing.

And here the result is. All hardware, softwares and OLS, OBLS are working well.

 

– Both clients work well and the core functions are the same.

– Personally, I prefer OLS client interface more, its interface is cool

– OLS client can be easily created new plugins with just a putting a file. I want to learn more about this function. Can I add new protocol decoding function as simple RC5 or complex LIN? Can some one point me out?

– I have an idea to test 200MHz sampling capability. I will update soon.

Updated :

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