Marketting Research / Focus Group
Granz
Posts: 179
I am looking for some help here.
Many of you who went to UPENE met me and saw my packets of parts. Thank you for the purchases that you made there. Now, I am trying to fine tune a couple of my products. There are also a couple of books with kits in the works, one for total beginners, and another which I hope to use for a college-level, semester-long course in microcontrollers; these will include the kits. I need your help (those who went to UPENE as well as those who did not) to provide useful products for my customers.
My current Digital Interface Kit consists of the following parts:
1) 6 LEDs, 2 each of Red, Yellow and Green
2) 4 Miniature Pushbuttons, Momentary Action, Norm Open
3) 1 Mini speaker, with a mounting connector for plugging into a breadboard
4) 1 Transistor for amplifying the speaker signal
5) 1 Serial EEPROM (Currently 24C01A, but subject to change)
6) 1 7-segment single digit display
7) 15 360-ohm resistors for current limiting for displays and transistor amplifier, and pull-up/pull-down
8) 1 small card with a schematic for a simple transistor amplifier
I also have an Analog Interface Kit (unfortunately did not have for UPENE), consisting of:
1) 1 Thermistor, NTC
2) 1 Photo-resistor
3) 1 Operational Amplifier (Currently LM358, but subject to change)
4) 2 10K-ohm Potentiometers
5) 1 small card with the specs for the thermistor and photo-resistor and a simple idea for using the Op-Amp as a single-bit A/D converter
Finally, I have a combo kit which consists of both parts lists. There will probably also be another kit or two for robotics, industrial control and possibly hydro/pneumatic system control.
The purpose of these kits is to give the experimenter the basic parts needed for learning about control systems. This is for learning and not for going into production, or even necessarily to build useful projects (although both of these could be done - within limits, learning is the purpose, not production.) Thus, while not trying to discourage people who want to build a production project, my target is the reader of the two above-mentioned books and people who would be likely to read that type of book.
I have four questions which I would like some discussion on:
What do you consider essential, basic parts that are missing from these kits?
What parts do you see in these kits, which should never have been added to begin with?
Do you consider these kits to be a valuable addition to a beginner or a more experienced person who is learning new techniques?
What kind of price range (without tax or shipping) would you expect to pay for one of these two (Digital and Analog) kits.
Thanks for your help with these questions.
Art
Many of you who went to UPENE met me and saw my packets of parts. Thank you for the purchases that you made there. Now, I am trying to fine tune a couple of my products. There are also a couple of books with kits in the works, one for total beginners, and another which I hope to use for a college-level, semester-long course in microcontrollers; these will include the kits. I need your help (those who went to UPENE as well as those who did not) to provide useful products for my customers.
My current Digital Interface Kit consists of the following parts:
1) 6 LEDs, 2 each of Red, Yellow and Green
2) 4 Miniature Pushbuttons, Momentary Action, Norm Open
3) 1 Mini speaker, with a mounting connector for plugging into a breadboard
4) 1 Transistor for amplifying the speaker signal
5) 1 Serial EEPROM (Currently 24C01A, but subject to change)
6) 1 7-segment single digit display
7) 15 360-ohm resistors for current limiting for displays and transistor amplifier, and pull-up/pull-down
8) 1 small card with a schematic for a simple transistor amplifier
I also have an Analog Interface Kit (unfortunately did not have for UPENE), consisting of:
1) 1 Thermistor, NTC
2) 1 Photo-resistor
3) 1 Operational Amplifier (Currently LM358, but subject to change)
4) 2 10K-ohm Potentiometers
5) 1 small card with the specs for the thermistor and photo-resistor and a simple idea for using the Op-Amp as a single-bit A/D converter
Finally, I have a combo kit which consists of both parts lists. There will probably also be another kit or two for robotics, industrial control and possibly hydro/pneumatic system control.
The purpose of these kits is to give the experimenter the basic parts needed for learning about control systems. This is for learning and not for going into production, or even necessarily to build useful projects (although both of these could be done - within limits, learning is the purpose, not production.) Thus, while not trying to discourage people who want to build a production project, my target is the reader of the two above-mentioned books and people who would be likely to read that type of book.
I have four questions which I would like some discussion on:
What do you consider essential, basic parts that are missing from these kits?
What parts do you see in these kits, which should never have been added to begin with?
Do you consider these kits to be a valuable addition to a beginner or a more experienced person who is learning new techniques?
What kind of price range (without tax or shipping) would you expect to pay for one of these two (Digital and Analog) kits.
Thanks for your help with these questions.
Art
Comments
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Computers are microcontrolled.
Robots are microcontrolled.
I am microcontrolled.
But you·can·call me micro.
If it's not Parallax then don't even bother.
I have changed my avatar so that I will no longer be confused with others who use generic avatars (and I'm more of a Prop head then a BS2 nut, anyway)
MC,
Thanks for your input. I was considering an A/D and/or a D/A converter, sounds like I need to consider it more strongly. Have you used any in any of your circuits? What are your favorites? Do you prefer the serial or parallel interfaces?
Art
Also, for pull-up and pull-down resistors it seems a lot more common to see 4.7K or 10K used.
Since resistors are pretty inexpensive these days you may want to offer a small variety pack for the Analog work with at least a couple of each of the common resistors: 100 ohm, 1K, 1.2K, 2.2K, etc. Maybe ask what other common resistors values are used or review existing projects to see what others are commonly using and base the parts kit on that.
Robert
You should use ADCs that use the SPI protocol like the MCP3202 www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010532. This would build on the experience with the SPI EEPROM (or vice versa).
For DACs, you could use other techniques like a resistor ladder (en.wikipedia.org/wiki/Resistor_ladder) or PWM (like the PWM statement in PBasic or the use of the cog counters in the Propeller). If you're using PWM, you could use your op-amp for buffering.
The resistor value and the 24C01 choices were made because I already had a large stock of them on-hand. For future refills I will take your ideas into consideration. Robert, you are absolutely correct - I had not thought about the power drain with the 360 ohm vs. the 470 or 560 ohm current limiting resistors - thanks, I will be using larger values in the future.
Mike, what about the difference between IIC and SPI? Which do you see more often? I see them about equally, so was not sure which to include, so I just went with what I already had on hand. I decided that if they used either one in training, then that experience would be able to be applied to the other interface with minimal trouble. As far as the size, I decided that for training purposes, that should not matter much; once the student gets experience with any storage, that should transfer. Ex
I like the idea of providing at least a 4-bit resistor ladder D/A, pretty low investment and every control engineer should at least know what a resistor ladder is. I remember seeing that in the ET-3400 course that I taught in the early '90s, and thought that it was pretty good then.
These kits are to be very generic. I will probably slightly customize them for the processor when I include them with a book/course. My first book is based on the Tiny13, and so that kit will be custom for that chip (i.e. no 8-bit I/Os for a chip with only 5 I/O pins), on the other hand, I have recently begun a book/course based on the Prop, so I wouldn't have any troubles with an 8-bit resistor ladder for that one, where a 4-bit ladder would be appropriate for the Tiny13.
Anyone else?
Thanks again,
Art
Price range? Less than 4x your cost [noparse]:)[/noparse]
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
--Steve
Propeller Tools
The issue with I2C vs SPI is that I2C is relatively complex and requires much more code to implement than SPI.· For an example, look at the amount of code needed for a BS2 for each protocol.· There's a Nuts and Volts Column that provides the I2C routines.· If you're using a Propeller, it probably doesn't matter because there's more memory and speed available.
·