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zeke

Custom circuits on demand?

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I'm just brain storming here so be easy on me. I'm just thinking out loud.

 

Would there be any interest by the forum members for a custom circuit design service?

 

What I mean is, you've made yourself a circuit and you've got your code working. Do you now want a circuit board designed for it? Do you want to make more than one? Do you want someone to help you put it together?

 

I'm interested in exploring the idea here.

 

I'm an engineer with a lot of spare time on my hands. I'm eager to stay busy and improve my skill set and resume.

 

What modules would you like to have for your LaunchPad or MSP430 experimentation?

 

Here's a list of ideas for circuit shields I put together last night:

1. LCD display

2. LED display (7-Segment or AlphaNumeric)

3. A/D inputs

4. Fiber optic interface

5. Serial Communications (UART/I2C/SPI)

6. Temperature sensors

7. Pressure sensors

 

I was contemplating a main board based upon the MSP439F5438A because it has a crap load of I/O and memory. We can use the LaunchPads or the EZ430 to program and debug it.

 

We could physically arrange it so that the shields plug into strips of 0.1" spaced pin headers.

 

Who knows? Maybe we could create our own community hardware project and everyone will beat a path to our door.

 

What do you think?

Thoughts or reactions?

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Speaking only for myself:

 

I kind of enjoy designing my boards in Eagle, and I already have a service or two to manufacture them. (I'm just a hobbyist, so just a few of each.)

 

Your ideas on shields sound great, and I would be interested in purchasing at least four of the designs you listed. There are at least two web stores I know of that say shields are "coming soon," but I don't think they really know what the hobby market wants.

 

Here are my personal comments on the ones you listed:

1. LCD display -- Make sample code available and drive it with a 595 so you only use three pins. These will sell like hotcakes.

2. LED display (7-Segment or AlphaNumeric) -- Same as above: Sample code and keep pins used low.

3. A/D inputs -- Using external ADC chips (maybe SPI to keep pin count down) and provide sample code.

4. Fiber optic interface -- Not something I'm personally interested in.

5. Serial Communications (UART/I2C/SPI) -- Sample code + low pins = I'll buy three!

6. Temperature sensors -- Maybe not a shield, but an add-on sensor board for the SPI shield?

7. Pressure sensors -- Same as above.

 

Personally, I'm not too interested in another dev board. I have six different kinds as it is. I stick with the LaunchPad because of its low cost and because I can transplant the chips to my own boards. (Many of my other boards are SMD.)

 

I love your shield ideas, and I could help (parts ordering, assembly, web store) if you decide you need assistance.

 

tl/dr: Your shield ideas are great; the other two are already saturated markets.

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I guess I'll give my two cents as well.

 

I've never bought a shield, and at-least don't plan on buying one anytime soon. Why? there are too many form factors, for example I have the following development boards: Launchpad, Arduino Diecimila, STM32VLDiscovery, a STM32F103 breakout I made myself, and I'm also hoping to get an mbed. If I was to buy a shield, it would only work on ONE of them, but there's likely a chance I would like to use it on more than one, so for this reason I stick to breakout boards.

 

However, here's my comments:

 

1. LCD display -> How about a LCD serial backpack drvier using a MSP430? I know I've seen ones using PIC/Atmel chips to make a 4-8bit LCD serial enabled, but they were 20$~ for something so simple.

2. LED display -> Have you seen the MAX6958? looks like it would be a good solution for controlling up to 4-1/2, seven segment displays using only two I/0 ports (i2c). Infact, Maxim has a whole line of LED display controllers that look really interesting.

5. Serial Communications (UART/I2C/SPI) -> A breakout board for the FT4232H may be a good idea, having 4 in 1 serial would be really nice imo.

6. Temperature sensors -> saturated, places like iteedstudio, seeedstudio sell these for ~2-4$.

7. Pressure sensors -> same as above.

 

It would certainly be nice to have some breakout boards/dev boards for the higher end MSP430 chips that we can use our Launchpad to program.

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I am personally interested in creating msp430 web server using WIZnet's WIZ830MJ or WIZ811MJ.

When it comes to driving LEDs and LCD, I am in process of creating 2 things:

 

Serial to 8 digit - I am tired of wiring displays for each project, so I decided to use some custom chip like MAX6951, but it's not available in DIP and it's pricey. MAX6958 is available in DIP, but it's also expensive. Because of that, I am writing something that will work similarly to MAX6951, but will use only one msp430g, 8 transistors, could drive 8 or 7 displays, and use 2 wire I2C. I should have something ready early this week.

 

Serial to LCD - Serial LCDs are much more expensive, so I am working on a simple converter that will use 2 wire I2C to drive parallel 8 bit LCD. The hardware will use 2 595s and one extra chip to load data, 555, 74HC74, or similar. You will not be able read LCD, but that might be an option by adding extra chip. Once 20 pin msp430g chips arrive, I will also create serial backpack.

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...I am working on a simple converter that will use 2 wire I2C to drive parallel 8 bit LCD.

Having just (pretty much) finished my 4-bit code for my HD44780-based LCDs, I'd like to point out that you gain nothing but a bit of speed by using the 8-bit interface. Since you're using a (slower) serial connection anyway, you could cut down your BOM by using the 4-bit interface.

 

Just an opinion (and you know what they say about those :? ). I look forward to seeing your projects! :D

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I prefere naturally serial LCD displays. My favorites are http://www.lcd-module.com/products/dog.html

 

advantages:

- it's naturally 3V system, no need 5V power supply

- it's slim and sexy - i do not like standard LCD's with massive steel frame and big PCB

- it's relative cheap (compared to another serial-connected LCD)

- wide range of backlight colors, include full RGB version (yum!)

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I've been thinking of picking up a couple Nokia LCD's..

 

http://iteadstudio.com/store/index.php? ... cts_id=155

6$ for a 84x48 LCD would be useful for a lot of projects.

 

http://iteadstudio.com/store/index.php? ... cts_id=133

They also have some 2.4 inch TFT LCD's for 18$, been thinking of getting some of them to try with my ARM DEV boards.

 

Correct me if I'm wrong, but the only difference when you driver a LCD in a higher bitrate (IE 8 bit instead of 4bit, or 16 bit instead of 8bit) is you would be able to get more frames per a second rendered to the LCD?

 

Personally, I'm looking for the cheapest solution for adding LCD/LED displays to my projects, I have a hard tome splurging for a LCD screen that sometimes will cost more than the entire project.

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Correct me if I'm wrong, but the only difference when you driver a LCD in a higher bitrate (IE 8 bit instead of 4bit, or 16 bit instead of 8bit) is you would be able to get more frames per a second rendered to the LCD?

Generally speaking, yes, you're correct. Mind you, the built-in refresh rate on the HD44780 variations out there will probably be the limiting factor on how many frames-per-second you can get for animation effects. The refresh rate on some of the White-on-Blue HD44780 displays I use is so slow that I can't see the "rolling odometer" special effect on them until I slow down data transfer to some useless rate.

 

Personally, I'm looking for the cheapest solution for adding LCD/LED displays to my projects, I have a hard tome splurging for a LCD screen that sometimes will cost more than the entire project.

I'm in the same boat and I've looked at various methods. Myke Predko's 2-pin shift register method is pretty neat and cheap. You could also use an inexpensive 74HC595 in a number of different configurations using 3 to 5 pins (see one example below). Once when challenged to design a 1-pin Serial LCD interface with a small footprint (in terms of board space), I found a way to feed the LCD (with its 6 inputs) with an 8 pin PIC (which has only 5 outputs).

 

file.php?id=170

 

All in all, I think you're better off designing an LCD Backpack. We can get MSP430G2231's for the asking (samples) so it would be a pretty inexpensive interface with much more capability than the other "cheap" interface methods. And shouldn't we be able to implement a Serial, SPI, and/or I2C interface with the '2231? The hard part (for me) is coming up with the money to make professional PCB's.

 

Some interesting project ideas guys. Keep 'em coming.

 

Cheerful regards, Mike

 

 

post-1059-135135495959_thumb.png

 

post-1059-135135497413_thumb.png

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...Myke Predko's 2-pin shift register method is pretty neat and cheap. You could also use an inexpensive 74HC595 in a number of different configurations using 3 to 5 pins (see one example below).

...

All in all, I think you're better off designing an LCD Backpack. We can get MSP430G2231's for the asking (samples) so it would be a pretty inexpensive interface with much more capability than the other "cheap" interface methods. And shouldn't we be able to implement a Serial, SPI, and/or I2C interface with the '2231?

 

Nice! This is what I was thinking exactly and what I am working on, either use 595s for 2 pin comm (555 would detect missing clock and latched 595s, hence no need for 3 pin) or just use cheap 2231s or 20pin version for 2 way comm.

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