I thought the Arduino SCK (D52) must be routed to SCK of the MCP3204?
If i swap them "Arduinos SCK" goes to "CS of MCP3204" and "CLK of MCP3204" to a digital pin of the Arduino?

Ups, i did forged the attachment in the last posting.
I think i need more sleep 

Ok, next one

Now i need to read allot about the SPI stuff and why it's now hardware with the 74LVC1G125W5.
It means i need a 74LVC1G125W5 for every device now that uses SPI (SDcard, Ethernet...)?

Thanks.
Just was asking cause a lot of stuff out there does not work
with some class's and has GB limitation (like a lot of smartphones).

I'm not joking. Never so a lever on a poti - only knobs.
I mean are there some to buy?

If not need some aluminum square and need to make a thread from the side for a screw.

Hi,

i can't find what the maximum microSD size is for the Ethernet Shield.
And what speed class works? SDHC 2, 4, 6, 10?
Does class 10 make sense?

A hole in the top of the valve lever and a servo linkage would not be a problem.
But what to use as lever on the potentiometer, hm?

What would be the best value for the potentiometer - 10K ?

From left to right its 170mm (6.7in).
So 20 LDRs every 8.5mm (0.35in) would give me 0%, 5%, 10%...

I also thought about ultrasonic on the side of the lever. But at 0% and 100% the lever is tilted.
So i have no idea how to do it.

The linkage/potentiometer solution would be very precious. But where to mount the potentiometer
and also there is the tilt problem.

So looks like a infrared LED/laser on the lever and a semicircle with LDRs in front is the easiest way.
Maybe i can count in 2,5% steps - the positions when the laser is between two LDRs?

Some tips on laser and LDRs?

Hi,

i have a mixing valve (hope you call it like this in english) with a lever.
The lever moves from left to right and vice versa.
The valve is driven by a 230V motor.

I need some ideas how i can log the leaver position.
Is there some tension sensor or something like this out there?

I attached some pictures.

Ok, i now first order parts that i can start to build something.
But i can't find the 74LV1G125. Not at farnell, not at digikey and in no German shop...
I think it's more future prove to use the 74LV1G125 cause i want to log the data to a SD card
have the network shield and also want to build some radio control for a water-pump (enocean if possible).
Does the wire from the heating system thermistors to the MCP3204 not affect the output of the thermistors (wire resistance)?
Or the 10K resistors? Not that the heating system turns into a air conditioning systems

Maybe its a big thing for an Arduino beginner. But like cabinetmakers say: "start with something
you like and something you have fun with. Don't select your project by easy or difficult".

I think it's learning by doing. And if the help here is so great like yours, than we can build a machine
to take over the world *lol

Ok, next try (attachment)

And it doesn't matter which ADuM logic output i connect to which pin on the MCP?
Your Arduino pin naming is confusing me - SCLK = Pin 52 SCK?

And should i take the ADUM6401ARWZ-ND or the ADUM6401CRWZ-ND?

Sorry but now I'm totally confused on the iso side.
Even with the MAX6145 i need the LC network?
Where to place the MAX6145?

Ok, here the circuit.

To i need the smoothing capacitor if i use the MAX6145?

Is the circuit correct?

Ah, didn't know this dc-dc-converters.

Yes all thermistors have common ground.
I have 4 so i need 2 ADUM6401.

The central heating connections are:
AF1 = 0 volt ground
AF2 = outside air thermistor
KF2 = furnace thermistor
VF2 = underfloor heating water thermistor
BF2 = hot water storage tank thermistor

The ADC chip means i read the voltage on the Arduinos digital inputs?
Do you have an example circuit diagram to give me a kick-start?

For the evaluation board i think you mean this one: http://www.analog.com/en/evaluation/eval-adumqs/eb.html
But it's a little bit to difficult to get here in Germany.

Hi,

i want to read the temps from my central heating system.
I don't have the specs of the thermistor's but tables from the central heating manual (see attachment).
I can measure the voltages with my multimeter and if i look into the tables it looks ok.
But all thermistor reading examples i find require the usage of the Arduino voltage (voltage divider circuit).
Is there a way to read the voltages from the thermistors without coupling the central heating and Arduino voltage?

Attachment:
Table 1: furnace water temp & underfloor heating water temp
Table 2: outside air temp
Table 3: hot water storage tank (water temp)

Thanks for help in advance :-)