Gina

Thanks Kev they look good.

I'm wondering whether to put the 5m mast in a place where I can get at it relatively easily rather than where the wind would be clearest.  ATM I have no weather station so almost anywhere would be better than nothing.  I also need to consider that I'm not getting any younger.

One thing I've found in the past is problems with the miniature ball bearings with damp causing corrosion.  I'm wondering about using PTFE and SS plain bearings.

One thing I've found with the reed switches is they have considerable hysteresis (distance between closing and opening).

I might yet go back to optical sensing.

8 hours ago, 7170 said:

16kR is a standard E28 resistor.

Yes some are rather close but lots of people connect up that wind vane to  arduinos with success. There must be a method in the madness somewhere 😀.

Do you have a laser printer, maybe a diode measuring an led shining through a circular piece of laser OHP film with varying density around it? Similar idea to a variable density optical soundtrack on old 16/35mm film prints.

No, I don't have a laser printer.

16K isn't either but maybe 15K is near enough.  OTOH some of the voltage values are very close!

But several of those resistors aren't preferred values.  No problem if manufacturing the resistors but we amateurs have to use the resistors we can get.

Pretty much decided to go with the reed switches for a couple of reasons.  I was going to use a cylindrical arrangement but magnet and reed switches need to be something like 8-10mm apart so I think the traditional radial arrangement is going to be better, may be easier to implement too.  Makes it easier to adjust the distance between magnets and reed switches to get the right overlap in operation.

I have a MUX chip it's an ESP32! 🤣  I like the 1-wire circuit but replacing the 1-wire with ESP32 which does everything.

Nuts to that!! 🤣  Just a bit of fun anyway - may play again later.

I'm sure the best option is the ESP32 and either 8 digital or 4 analog inputs and the 1-wire circuit.

I'm wondering if I can produce a resistor network with standard resistor values viz. 1, 2.2, 4.7, 10, 22, 47.

Suppose we make inbetween values by adding another resistor in series, like this :-

1. 1
2. 1 + 0.22
3. 1 + 0.47 = 1.47
4. 2.2 + 0.47 = 2.67
5. 2.2 +1 = 3.2
6. 4.7
7. 4.7 + 1 = 5.7
8. 4.7 + 2.2 = 6.9

Then between those 8 values we have adjacent resistance values in parallel giving in ohms :-

1. 1000
2. 549.54
3. 1000 + 220 = 1220
4. 666.7
5. 1000 +.470 = 1470
6. 948
7. 2200 + 047 = 2670
8. 1456
9. 2200 +1000 = 3200
10. 1904
11. 4700
12. 2576
13. 4700 + 1000 = 5700
14. 3121
15. 4700 + 2200 = 6900
16. 873

Putting these in numerical gives

1. 549
2. 666.7
3. 873
4. 948
5. 1000
6. 1220
7. 1456
8. 1470
9. 1904
10. 2576
11. 2670
12. 3121
13. 3200
14. 4700
15. 5700
16. 6900

Some of these are quite close together.  Maybe some primary values (8) could be adjusted to separate the secondary values (16) better.  The resistance values would translate to voltage if the array were fed with a constant current but that would make the lower values very close together.  Better would be to feed from a constant voltage through a resistor, then the lower switches would result in a higher current and tend to spread the lower values.

All this is getting very complicated and probably not worth the trouble!

The reed switches have arrived and I've checked their operation.  They're very sensitive one of my little 3mm cube magnets will operate one at 5 or 6mm.

Labelling the reed switches 1 to 8 from the bottom upwards...  Assigning v to the voltage across each of the series resistors - 1/7th of 3.3v

1. 1 - 0v
2. 1&2 - 0.5v
3. 2 - 1v
4. 2&3 - 1.5v
5. 3 - 2v
6. 3&4 - 2.5v
7. 4 - 3v
8. 4&5 - 3.5v
9. 5 - 4v
10. 5&6 - 4.5v
11. 6 - 5v
12. 6&7 - 5.5v
13. 7 - 6v
14. 7&8 - 6.5v
15. 8 - 7v

Then we would have 16. 8&1 - 7/2 = 3.5v which is the same as 8. with 4&5.   So no difference between positions 8 and 16.  I though I'd cracked it but not so!!

Here is a resistor network using preferred values that gives a voltage proportional to angle in 16 steps.  Except that it has a serious fault!!  I think.

Yes, I have a circuit diagram for using 8 reed switches and a resistor network giving a single analogue signal to feed to the ESP or whatever.  Trouble is the resistors are unusual values.  OK, these could probably be produced by using preferred values is series or parallel but it's a lot of resistors whereas 8 wires from one side of the reed switches could go to the ESP with the other ends connected to Gnd - much simpler.  OTOH the 1-wire circuit above with 4 analog signals could be fed to the ADC inputs of an ESP32 giving another (more complicated) possibility.

12 hours ago, sloz1664 said:

Hi Gina

The  NodeMCU Module ESP8266 ESP-12E WiFi devices look good and nice and cheap. How are you going to incorporate these into your design?

steve

Here's a first revised block/circuit diagram.

I shall be using the ESP32 for the wind sensors then and may add the rain gauge and maybe light level sensor - photo-voltaic cell.

Just checked the observatory roof control thread and the requirements are 1 analog input, 6 digital inputs and 2 digital outputs.  I think the NodeMCU Module ESP8266 ESP-12E could cope with this.

I may have a change of plan with a much simpler set of electronics.  Using a NodeMCU Module ESP8266 ESP-12E WiFi device.

I reckon I may be able to use the ESP8266 for my observatory roof control.  Current design uses an RPi and Arduino Nano.  It only needs the Nano to read one analogue signal otherwise it's digital I/O.

But an extra chip!

Well, well, well, that's the same circuit as an earlier WS of mine using 1-wire.  Except mine didn't use two reeds for the anemometer.

The ESP8266 has just one ADC input.

The NodeMCU Module ESP8266 ESP-12E version has just been delivered.  It's only very slightly smaller than the ESP32!  So I haven't gained much - just a couple of quid cheaper.  I may go back to the ESP32 and use this for something else.  I'm not sure there's any advantage in the 8266.

Looks like the NodeMCU Module ESP8266 ESP-12E that is on the way to me won't work in the way I want.  There may be a way round it using fewer pins - I shall have to think...

I don't quite understand your first paragraph, I'm afraid.

I have nothing ATM.  My plan is to connect the reed switches to the ESP and use internal PU if available with the other ends connected to Gnd.