First PCBs arrive
Brian Fairchild
Posts: 549
In the tradition of show-and-tell...
The PCBs have arrived for my first unit to include a Propeller. The prop lives with the main processor (an AVR) and provide two VGA outputs, an SD card, a serial port to talk to the AVR, and two sets of keyboard and mouse connector (one set shares pins with the SD). And to think that only a few months ago I'd have been using a 2x16 monochrome LCD display and now I have full colour VGA capabilities.
I'm amazed at how easy it was to incorporate the propeller into the design. And how easy testing was - no more 'printf' or blinking LEDs, just send stuff to the screen.
The PCBs have arrived for my first unit to include a Propeller. The prop lives with the main processor (an AVR) and provide two VGA outputs, an SD card, a serial port to talk to the AVR, and two sets of keyboard and mouse connector (one set shares pins with the SD). And to think that only a few months ago I'd have been using a 2x16 monochrome LCD display and now I have full colour VGA capabilities.
I'm amazed at how easy it was to incorporate the propeller into the design. And how easy testing was - no more 'printf' or blinking LEDs, just send stuff to the screen.
1541 x 744 - 886K
Comments
I'm intrigued:
What does the AVR do there that another Prop could not ?
What AVR app. needs two screens ?
If this is confidential, general terms would do.
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For me, the past is not over yet.
1) Knowledge - I've been using AVRs for about 5/6 years. These boards are going into the 'production' version of a unit which we've been trialling for the last year so most of the AVR code is already written. Having used micros for around 30 years it's taking a while to learn 'the propeller way'.
2) Memory - The AVR I'm using, the mega644P, has 64k bytes of code space and 4k bytes of RAM. The plan is to upgrade to the 1284P (128k/16k) in the next few weeks once Atmel start shipping. Memory space, especially RAM, is an issue.
The Prop has been a wonderful discovery for me with it's display capabilities. Previously I've used monochrome character LCD displays with 6 button navigation pads. Now I can stick in a VGA connector and keyboard connector for less money! Everything I do is low-volume high-value stuff so loading a TFT display into the system is never an issue.
The next unit I'm doodling out at the moment will probably be a prop-only unit if only because it lends itself so well to the COG and HUB architecture of the Propeller.
Screen 1 is for the user interface with a keyboard and mouse. Screen 2 is for a status display so you can always see what's going on. The application is fairly critical in a 'it-goes-wrong-and-someone-gets-badly-hurt' kind of way. The AVR is talking over a very very heavily checked and protected data link to remote units. The remote units have two processors in them which have to agree on what to do before anything will happen. On top of that is a 'hardware' layer where, once the remote CPUs agree on what is going to happen, then the power rails which travel alongside the data, have to be doing certain things before any end action can take place.
It's a wonder I sleep at night!