Could you tell me more? When and how would I get dht22 working on the BBB? Thanks!
On Thursday, March 13, 2014 5:59:55 PM UTC-4, JrBenito wrote: > > Latest Kernel has DHT11 and DHT22 drivers under IIO subsystem. We shall > see it working on BBB very soon. > > regards, > Benito. > > On Friday, February 21, 2014 11:07:01 AM UTC-3, [email protected] wrote: >> >> Hi, >> >> I am trying to use this code with an Adsong dht22 (am2302) temp/rh sensor >> running on the BBB. I haven't used C for a number of years so I am kind of >> rusty. What modifications did you make to compile it with g++ on the BBB? >> How does portG map to the pinout on the BBB? Or what pin do I connect the >> data line to on the BBB? >> >> Thanks! >> >> On Tuesday, October 8, 2013 11:06:43 AM UTC-4, Lloyd Bailey wrote: >>> >>> You can modify this code http://www.acmesystems.it/?id=89 >>> >>> I have and it works on my Beaglebone black. :) >>> >>> On Wednesday, 28 August 2013 04:25:30 UTC+1, CJNZ wrote: >>>> >>>> Hi Hunyue, >>>> >>>> I am trying to get the SHT15 working on a classic Beagle. >>>> I realise this is an old thread, but I am struggling a bit with the >>>> code. >>>> Do you still have a code example that you could share? >>>> Did you just connect clock and data to standard GPIO and 3.3 and ground? >>>> >>>> Thanks, >>>> CJ >>>> >>>> On Tuesday, October 16, 2012 7:41:20 PM UTC+13, H wrote: >>>>> >>>>> On Mon October 15 2012 19:08:51 Aaron Patterson wrote: >>>>> > On Mon, Oct 15, 2012 at 4:58 PM, Dan Watts >>>>> <[email protected]> wrote: >>>>> > > Hi, >>>>> > > >>>>> > > You're right: the Adafruit code does look odd. >>>>> > > >>>>> > > As you say, to initiate communication with the DHT11/DHT22, >>>>> > > you're supposed to pull the signal low for > 18 ms, then >>>>> > > high, then wait for the signal to be pulled low again. >>>>> > > Their code appears to skip the pull-high part. I can only >>>>> > > assume that the Pi stops pulling the signal low when it >>>>> > > switches to input mode. >>>>> > > >>>>> > > The only possible problem I can see in your code is that you >>>>> > > might not be pulling the signal low for long enough: perhaps >>>>> > > the usleep(2000) should be usleep(20000)? Also, trying to >>>>> > > catch that 40 microsecond signal that begins the DHT22's >>>>> > > response is tricky - that's probably why the Pi's code >>>>> > > doesn't pull the line high explicitly. Perhaps dropping the >>>>> > > digitalWrite(HIGH) from your code would have the same >>>>> > > effect? >>>>> > >>>>> > I gave both of these a whirl, and they did not work. I am >>>>> > able to see the signal on my oscilloscope, though I'm new to >>>>> > using the oscilloscope, so I'm not 100% sure. >>>>> > >>>>> > > I have my doubts about whether reading data from the DHT22 >>>>> > > can work reliably from Linux code, given the tight timing >>>>> > > involved. Apparently the Adafruit code is managing to do it >>>>> > > on the Pi, but there is a warning at the beginning of their >>>>> > > tutorial saying it may not work, and perhaps the library >>>>> > > they are using is more optimized than what is available for >>>>> > > the Bone. >>>>> > >>>>> > Yes, I read that. I'm starting to have the same doubts as >>>>> > well. >>>>> > >>>>> > > Personally, I wimped out and use a separate processor to >>>>> > > read the DHT22. I actually use a .Net Micro Framework >>>>> > > processor for this (which surprisingly is able to handle the >>>>> > > timings) and serial I/O, but something like the ATTiny2313 >>>>> > > and I2C would be a better design. >>>>> > >>>>> > I'm starting to think I might need to do the same. I'll give >>>>> > the Pi a try, and I've got an Electric Imp on the way, so >>>>> > I'll probably try it too. >>>>> >>>>> >>>>> That would appear to be an overkill to toss in another processor. >>>>> Prehaps a different part would be more appropriate? >>>>> >>>>> FWIW, I recently got a humidity sensor working on the classic >>>>> Beagle. This is the SHT-15 part. Everything pretty much was drop >>>>> in. Hookup. The setup was: >>>>> >>>>> SHT-15 - <Level Converter, 3.3V source> - Beagle Classic. >>>>> >>>>> Driver for it was all upstream. It is built on top of the GPIO >>>>> subsystem. The level converter and 3.3V are option on the >>>>> beaglelcd board. Write up for it will be posted as time permits. >>>>> >>>>> Since IO on the bone is 3.3V, the level converter won't be >>>>> needed. >>>>> >>>>> > >>>>> > I've built a meat curing fridge, and I'm trying to build an >>>>> > internet enabled controller. I've built a monitor for it >>>>> > using the TI Launchpad, and I'd like to build something that >>>>> > will post the information to the internet (without hooking up >>>>> > to my laptop and reading from a TTY). I suppose I could try >>>>> > XBee, but everything seems much harder since I'm not using an >>>>> > Arduino. :-( >>>>> > >>>>> > Anyway, thanks for the response. If I can't get the Pi or the >>>>> > Imp to work out, I'll hook the Launchpad up to the Bone via >>>>> > UART. >>>>> > >>>>> > Again, thanks for your time. I appreciate the response! >>>>> > >>>>> >>>>> -- >>>>> Hunyue Yau >>>>> http://www.hy-research.com/ >>>>> >>>> -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
