Hey all, I am trying to find a cheap air flow sensor for my WebControl, but all three of my analog inputs are full so it would need to connect to the digital inputs. A digital version of this analog one (http://shop.moderndevice.com/products/wind-sensor) would be perfect but I can't seem to find anything, any ideas or ones you have used? I admit I am not totally sure how the digital inputs need to work anyway : )
Digital Air Flow Sensor?
- Thread starter ChubRock1
- Start date
CAI_Support
Senior Member
Hi,
If your humidity sensor is not used, you can use that input as your analog input. Just need to add 100K resistor to make it full range 10V.
Another way to do is to have an analog mux to switch in the analog input, wait for one second, do a measurement, then switch in another analog input. The analog mux can be controlled by TTL output.
If you consider to use wind sensor like this one:
http://www.ebay.com/itm/271095468732
you can connect it to your TTL 1 input, then setup that input as counter, or frequency counter to count the pulses of this kind of wind sensor.
If your humidity sensor is not used, you can use that input as your analog input. Just need to add 100K resistor to make it full range 10V.
Another way to do is to have an analog mux to switch in the analog input, wait for one second, do a measurement, then switch in another analog input. The analog mux can be controlled by TTL output.
If you consider to use wind sensor like this one:
http://www.ebay.com/itm/271095468732
you can connect it to your TTL 1 input, then setup that input as counter, or frequency counter to count the pulses of this kind of wind sensor.
Thanks for the idea, I am using the Humidity sensor also, so I may have to look into the analog mux option. Is there one you could point me to and is there any doc that would explain how to control it with TTL?
On the sensor, the air flow rates are very low so a normal wind sensor would likely not register most of the time. The one I referenced seemed to be for more sensitive readings, do you see any issue with using that one?
On the sensor, the air flow rates are very low so a normal wind sensor would likely not register most of the time. The one I referenced seemed to be for more sensitive readings, do you see any issue with using that one?
CAI_Support
Senior Member
I realized the sensor you using is for very low flow rate.
There are analog switches like this one:
http://www.maximintegrated.com/datasheet/index.mvp/id/4363
but that is limited to 5V range, cost < $4 each.
Another way to do is to have second WebControl board, second board feed to the first board using WEBSET call over network. In the WEBSET configure the URL to be setvar.cgi Calling that every two to three seconds, to update the first board.
There are analog switches like this one:
http://www.maximintegrated.com/datasheet/index.mvp/id/4363
but that is limited to 5V range, cost < $4 each.
Another way to do is to have second WebControl board, second board feed to the first board using WEBSET call over network. In the WEBSET configure the URL to be setvar.cgi Calling that every two to three seconds, to update the first board.
CAI_Support
Senior Member
Or you can use this analog switch IC to do the trick:
http://www.analog.com/en/switchesmultiplexers/multiplexers-muxes/adg529a/products/product.html
Have DA and DB connected together to one analog input. A0 and A1 connect to two TTL output to switch which analog channel to read from.
Give it one second or more after switching analog channel, then read the input for that channel.
http://www.analog.com/en/switchesmultiplexers/multiplexers-muxes/adg529a/products/product.html
Have DA and DB connected together to one analog input. A0 and A1 connect to two TTL output to switch which analog channel to read from.
Give it one second or more after switching analog channel, then read the input for that channel.
bbsux
Active Member
why not add the 1wire 4 analog expansion? I know DS is discontinuing them but they are still out there.
that way you can just use the moderndevices analog sensor.
here's a ready made one I bought that works great with my webcontrol $17.50 + $8 shipping from china
http://pcsensor.com/index.php?_a=product&product_id=45
ebay : http://www.ebay.com/itm/PCsensor-1-wire-Quad-20mA-converter-usb-pc-current-sense-converter-1WAD-20mA-/321110746555?vxp=mtr&hash=item4ac3b125bb
that way you can just use the moderndevices analog sensor.
here's a ready made one I bought that works great with my webcontrol $17.50 + $8 shipping from china
http://pcsensor.com/index.php?_a=product&product_id=45
ebay : http://www.ebay.com/itm/PCsensor-1-wire-Quad-20mA-converter-usb-pc-current-sense-converter-1WAD-20mA-/321110746555?vxp=mtr&hash=item4ac3b125bb
CAI_Support
Senior Member
Good to know there are still DS2450 chip available. This package is also great! Thanks for posting the link.
CAI_Support
Senior Member
Hi BBSUX,
From the link you provided, it showed schematics, in that, it indicated using DS2450. Maxim IC made them in Thailand. We currently don't have any chip can directly replace it. The biggest problem for that chip was noise problem, if PCB not properly designed. If your experience is great with that device, then its PCB layout must be good.
From the link you provided, it showed schematics, in that, it indicated using DS2450. Maxim IC made them in Thailand. We currently don't have any chip can directly replace it. The biggest problem for that chip was noise problem, if PCB not properly designed. If your experience is great with that device, then its PCB layout must be good.
CAI_Support said:
I'm using them too (along with some amplifiers I made - http://general.rossw.net/webcontrol/4champ2-asmb.jpg) to read current from my solar arrays.
There is a little jitter - but very similar to a standard, unmodified webcontrol boards normal jitter.
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