24 replies to this topic

[Chris Walker]

I think the bigger point is what indimini stated about OneWire support: "I still don't understand why, when it is part of the standard 4.2 NETMF build, Go doesn't support it."

Oh, gotcha. Netduino Go can definitely support OneWire. But it doesn't have pins for OneWire to work on...it has GoPorts that you can plug modules into.

So we need modules which support OneWire and then we can use it over GoBus. We should be able to do that on Shield Base fairly easily, and maybe on the Gadgeteer Adapter as well.

Chris

[indimini]

Chris,

That sounds encouraging. When making a purchase decision, Go's extensible platform is what drew me from Arduino. Knowing that lesser capable arduino and Netduino/+ boards support OneWire, I was surprised to find that Go + Shield Base didn't offer this protocol, even with its support in NETMF 4.2 and a larger memory footprint of the Go controller.

I'm guessing that a good # of us asking for OneWire need it for our digital temp controls to support our home brewery setups. When technology gets in the way of beer production, something must be done!

[GregR]

Oh, gotcha. Netduino Go can definitely support OneWire. But it doesn't have pins for OneWire to work on...it has GoPorts that you can plug modules into.

So we need modules which support OneWire and then we can use it over GoBus. We should be able to do that on Shield Base fairly easily, and maybe on the Gadgeteer Adapter as well.

Chris

I was definitely referring to the Shield Base...not the Netduino Go by itself. I guess the bottom line for me is, since the Shield Base is supposed to bring Arduino 'compatibility' to the Netduino Go then I would expect that it would support everthing that the Arduino supports protocol wise.

Greg

[Chris Walker]

Thanks everyone for your feedback on OneWire and Shield Base. We've gone ahead and put down OneWire as the first new feature to add to Shield Base. We'll also add the OneWire NETMF class to Netduino Go, so using this feature will be seamless. We'll also create a OneWire profile for GoBus, so that any GoBus module can incorporate OneWire and integrate seamlessly with NETMF. Chris P.S. Right now we're working on a big firmware update for Netduino Go and Shield Base which will enable I2C--the last missing core feature. We expect to finish that around the end of October. Then we'll move Shield Base over to SPI-based transport (using the same native GoBus firmware as the Gadgeteer Adapter) and enable up to 8 Shield Bases plugged directly into Netduino Go.

[baxter]

For me it's very interesting, my problem is that i have to interface with DS18B20 temp sensors, i can't use others, because the DS18B20 it the one one i can get prefitted in a metal cylinder on the end of a cable, waterproofed.

Currently i use an 3.3V Arduino Pro Mini to read the sensors, and my hope is to read from my "module" via Serial on the shield base.

That's why i wanted a TLL level Serial Port GoBus module, rather than the RS-232 level one you are developing, much simpler and cheaper than the shield base.

We have some very basic ways to communicate in the world of electronics, TLL level Serial, SPI and I2C are probably the most popular. My dreams is to leverage the STM8S and make one small and inexpensive Go module, 2 x Serial, SPI and I2C.


But unfortunately i don't have the knowledge to do it well...

Hi Lunddahl,

To add 1-wire functionality to the shieldbase or Netduino/Plus, I would seriously look at the Picaxe. I have posted about this before,

http://forums.netdui...1-wire-support/

These chips have a tremendous amount of built-in functionality. As an example for the DS18b20, to Read a 12-bit temperature on pin B.1 and report the result

Code Example:

main:	readtemp12 B.1,w1	; read value into b1
	debug			; transmit to computer screen
	goto main

or to Read a raw temperature value from a DS18B20

main:	owout C.1,%1001,($CC,$44)	; send ‘reset’ then ‘skip ROM’ then ‘convert’ then apply ‘pullup’
	pause 750			; wait 750ms with strong pullup
	owout C.1,%0001,($CC,$BE)	; send ‘reset’ then ‘skip ROM’ then ‘read temp’ command
	owin C.1,%0000,(b0,b1)		; read in result
	sertxd (#w0,CR,LF) 		; transmit value
	goto main

They are equally simple for I2c and SPI. To program them, just use the Picaxe programming editor with a serial interface. The simplest way to give
the results back to the Netduino is via serial. I put together a protoshield awhile back to do some I2C testing. The shield uses a 20X2 part and runs a program that reads
continuously from a 24LC256 EEPROM and a DS3232mz+ RTC and reports the results via serial.

Baxter

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