EEVblog #313 – Bus Pirate LCD Debugging

EEVBlog-304As MrDEB contemplates using another LCD, Dave Jones has created another great video on using Dangerous Protptype's Bus Private for testing an LCD display.  I've mentioned the Bus Pirate here before - it'sa serial analyzer/interface that understands a number of protocols.  If you're trying to figure out an I2C, SPI, UART or One-Wire interface (among others) the Bus Pirate can be a huge asset.

Dangerous Prototypes makes an 74HC595- based converter to go from the serial protocol that the Bus Pirate understands to the parallel interface of a character LCD.  If this sounds at all familiar, it's a technique that been discussed by mrbasher and Mike here extensively in the past.

Dave makes quick work of checking out a 8x2 display with the Bus Pirate.  As with most of Dave's videos, there are lessons to be learned, including the dangers of using dual-row header cables.  Dave had a crossed cable between the Bus Pirate and the '595 adapter board which was quickly found and corrected.  If the cable had been reversed between the '595 adapter and the LCD, the outcome mat have been much worse.

Dave is very good at systematic troubleshooting - watch and learn.

EEVblog #313 – Bus Pirate LCD Debugging

 


Posted: 5 years 3 months ago by majenko #11210
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I must make myself a bus pirate - they are so useful.
Posted: 5 years 3 months ago by MrDEB #11212
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I see I am not the only one with LCD woes.
Thinking perhaps I should get one of these devices along with a PICKIT2.
Keep thinking about Jons use of two PICKIT2's at same time (ICSP and the USART).
Posted: 5 years 3 months ago by W4GNS #11209
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I see I am not the only one with LCD woes.

Posted: 5 years 3 months ago by Jon Chandler #11173
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...Keep thinking about Jons use of two PICKIT2's at same time (ICSP and the USART)...

I haven't done that in a long while - not since my second PICkit 2 found a new home with mrbasher.

In fact, I usually don't miss the option. Often during program dev, UART output is all that's needed to keep an eye on program operation. The Swordfish software UART support is pretty limited but it works fine for output. I outlined a trick some time ago to configure the software UART so you can program via ICSP and toggle the ICkit GUI to the UART tool screen and watch the program do its thing without changing any connections.

Not Quite Trivial - A Tip for using the Software UART with the PICKit 2

Where I need two-way UART comms during dev, I use a USB-UART adapter. Many od theese have been mentioned here.
Posted: 5 years 3 months ago by MrDEB #11179
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HOPEFULLY this will work with the Junebug I am presently using. I found the Junebug works better after I pulled the 18F1320 out.
Will let you know.
I see RB.7 is the PGD port on a 18F4520 as well.
THANKS hopefully this will save some time in monitoring the code flow. Have yet to power up the LCD Beer Cooler board.
Posted: 5 years 3 months ago by Jon G #11181
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So... Back to bus pirates...

I notice that there are a few different ones out there... Any recommendations?

Also, LOL at the "available at every 'one hung low'"
Posted: 5 years 3 months ago by Jon Chandler #11182
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Dangerous Prototypes is the creator of the open-source Bus Pirate and of the firmware. Their official supplier is Seeed Studios.

Sparkfun also sells a Bus Pirate of their own design. Since the Bus Pirate was released as an open source project by Dangerous Prototypes, Sparkfun is free to do so. Dangerous Prototypes receives nothing from Sparkfun sales.

I believe Adafruit also sells a version under similar conditions as Sparkfun.

Before deciding on anybody's version, I would check out the latest from Dangerous Prototypes and be sure no important new features are missing.

All of the firmware comes from Dangeroous Prototypes as far as I know.

The LCD adapter board is also open source. The Bus Pirate firmware supports the board configuration of the hardware from Dangerous Prototypes. Ensure a compatible configuration before ordering from another source. In response to the EEVBlog video, the latest greatest adapter board from Dangerous Prototypes adds an 8x2 dual row header.
Posted: 5 years 3 months ago by Jon G #11184
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I'm inclined to think that the one from the creators of it would be the best bet... Though I'm not sure of course without doing some research. This thing would certainly save me some time. It gets annoying breadboarding something just to test something simple out.
Posted: 5 years 3 months ago by W4GNS #11213
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I may be wrong here, it won't be the first time, but the way I read the webpage Sparkfun and Adafruit etc etc are distributors for Dangerious Prototypes, seems to me they would not be listed if they were doing there own little thing. http://dangerousprototypes.com/docs/Distributors

Also I can't seem to find where the commands are for that Bus Pirate, anyone know where they are hiding ?
Posted: 5 years 3 months ago by MrDEB #11214
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Off the coast of Somalia


LOL couldn't resist.
Going to look into getting one of these.

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