Is there already a component through wich i can get more IO’s on any board? I know you have boards with 60 IO’s, but thats not enough for a project i want to realize
Its leading to the direction to replace a sps where the application is not that time critical.
Chooseable for this i need extensions for analog and digital io’s for signals.
Something like can-extention or uext extention…
Does something like that exist, or are you planning to implement something like this to your products?
Can i access than from 1 fez board to the IO’s of the second one?
Well we talk about 100 IO’s. Is this solution endless expandable? And what do you mean with bus system? the Uext or can?
OK so digital IO’s can get realized by this solutuion (in case needed by reducing the voltage). What about the analog IO’s on the board? I haven’t found any documentation what they can. The range of voltage and ampere they can handle. Because 40% of the IO’s i need are analog… and the biggest board has 8 of them. and combining 5 of them to get the amount of needed analog IO’s is extrem expensive and now cost efficient. (i could use than the mini but still 5 times about 50 euro for 1 board)…
I get a set of analog signals. 1 set has 2 - 4 analog signals to read. My Project is flexible from 2 Sets up to 8 Sets. These values are positions of some motors measured my a wire which gives me analog signals. Than because there is hydraulic, i get the current preasure of the hydraulic also as analog. Than i also need digital IO’s so i can see if a motor has reached his limit up or down. It is for lifting cars and bigger vehicils. All Motors need to accellerate the same and need to be on the same height. This must be regulated very carefully.
So all about, there are about 40 analog IO’s and 30 digital IO’s.
So this is my current problem. (There is no time limit on this problem. So i have no hurry with this.)
Did you understand what i mean / want ?
But the current spec of the Analog and digital IO’s would realy interest me…
You can use the IO40 board to get all digital pins you need. For analog pins, you can connect any SPI, I2C or one wire ADC chip. Some of these chops are DIP so you can easily solder a board yourself. If you are not good with making boards, then you can easily connect any ready board that has one of the interfaces available on FEZ. This is an example but you have to make sure it will work [url]http://mayhewlabs.com/arduino-mux-shield[/url]
Since there are 8 channels on board, theoretically this can be expanded to 128 Analog Inputs. The range would be the same 3.3V as the original pins, and you can use the same control lines for all the chips, you’ll just have to keep track of what you are looking at. You’ll also need to keep in mind the settling time on the AIN channel when switching the multiplexor chip (typically you wait a few uS then average 10 or more readings to get a value).
By the way, that same multiplexor chip can be used as a digital port expander.
If you are working with higher voltage analog sensors, you’ll need to divide the value down to 3.3V max, as applying more than 3.3V to the analog input pins can damage the MCU.
IO40 board is a generic solution to give you control of many digital lines with a small number of uC lines consumed.
The way I2C is implemented on Fez it needs direct control of the i2c lines so a port extender solution won’t really work. you could try bit-banging the IO lines on the IO40 to emulate I2C but you won’t get the native I2C working thru a single IO extender let alone multiple.