tag:blogger.com,1999:blog-4922503085503427986.post4641045057095798934..comments2024-03-28T15:43:04.548-07:00Comments on Desert Home: Battery Operated Temperature Sensor, yet another revision.davehttp://www.blogger.com/profile/11608589214882334649noreply@blogger.comBlogger35125tag:blogger.com,1999:blog-4922503085503427986.post-6204188842381370642015-06-17T11:30:12.354-07:002015-06-17T11:30:12.354-07:00Thanks Dave.Thanks Dave.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-57556729599730939852015-06-16T11:00:42.940-07:002015-06-16T11:00:42.940-07:00You're going to get a huge spike from the rela...You're going to get a huge spike from the relay when you opereate it, so put the kickback diode right across the relay coils. Literally solder it right to the coil wires as close as you can get to the coils.<br /><br />Don't run any wires along with the coil wires that can pick up the spike from inductive coupling. Make sure the diode is a power diode, not a signal diode, a signal diode will last about three times before opening up and letting the spike get through.<br /><br />Do all that and you should be fine. I always put a small value cap and a large value cap side by side somewhere in the power circuitry to keep the various RF signals and periodic pulses that hang around the circuitry away from the processor, and so far, this has worked great for me.davehttps://www.blogger.com/profile/11608589214882334649noreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-1631975696388747342015-06-16T10:51:21.400-07:002015-06-16T10:51:21.400-07:00Thanks Dave, I am new to electronics and learn a l...Thanks Dave, I am new to electronics and learn a lot from your posts.<br />Now that I have this working, I am getting ready to connect my water solenoid to the XBEE.<br />For the water solenoid (I am using an N-Channel FET and a kickback diode).<br />The water solenoid and the voltage divider are both connected to a 12VDC supply.<br />I have protection on the XBEE pin driving the solenoid (FET and kickback diode), however the ADC pin D1 is directly connected to voltage divider, wanted to know if i should put kickback diode in the front of the divider? I am worried that my XBEE might get damaged if there reverse flow of current from the solenoid which needs 1.6amps to actuate, Appreciate any suggestion or recommendation.<br />Thank you - HG!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-51119740205935402892015-06-16T07:38:39.295-07:002015-06-16T07:38:39.295-07:00Glad I could help.Glad I could help.davehttps://www.blogger.com/profile/11608589214882334649noreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-69611398655762318462015-06-15T23:18:44.270-07:002015-06-15T23:18:44.270-07:00Hi Dave, actually i have to two projects, one was ...Hi Dave, actually i have to two projects, one was the temperature sensor (pro mini and xbee) which i built similar to yours and which is running fine and now 24/7 and its day 10. Thanks to you !!<br /><br />The second one does not have any micro-controller and is intended to operate a water solenoid with XBEE and is battery operated. So i copied the voltage divider only and this is the one i "was" having issues with the ADC on D1 until you came to my rescue. I have now have disabled the internal pullup on D1 and the ADC is working fine :-). PR=3FF7 did the job per your recommendation. So ones again Thank you very much!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-69081651120168714122015-06-15T20:50:46.057-07:002015-06-15T20:50:46.057-07:00OK, I'm confused, are you using an arduino (or...OK, I'm confused, are you using an arduino (or something like that) or strictly and XBee? It doesn't really matter though since the result would be the same, I just want to make sure I'm trying to answer the right question.<br /><br />Like I said though, when you're using a very high value voltage divider, any stray resistor sneaking in can mess it up. However, mine is working really well keeping track of the source voltage.davehttps://www.blogger.com/profile/11608589214882334649noreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-77897529342949341172015-06-15T15:59:04.997-07:002015-06-15T15:59:04.997-07:00Thanks Dave, that could be the reason. The XBEE...Thanks Dave, that could be the reason. The XBEE's do have the internal pull-up enabled by default. I will disable the pull-up on D1 and try. Should I also connect 1 micro farad cap between D1 and ground?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-81006518359233789252015-06-15T15:09:50.531-07:002015-06-15T15:09:50.531-07:00Ok, you're using the multi megohm voltage divi...Ok, you're using the multi megohm voltage divider. That does mean that you need a cap to lower the impedance of the pin. Double check the programming of the pin on the arduino. If you have accidentally programmed in the pull up resistor, it will max out the reading. You can't use the internal pullup resistor with megohm voltage dividers, it will overpower the circuit and give you a maxed out reading. It'll also cut the battery life some<br />davehttps://www.blogger.com/profile/11608589214882334649noreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-36468984297230307992015-06-15T14:07:13.452-07:002015-06-15T14:07:13.452-07:00Hi Dave, the circuit is the same as your diagram o...Hi Dave, the circuit is the same as your diagram on this post. Essentially I copied the voltage divider circuit from your post above. So yes it does have a capacitor.<br />I will try to play around with a potentiometer today to check if that would make any differance. <br />Thank you, HGAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-63086814649865845592015-06-15T12:55:38.340-07:002015-06-15T12:55:38.340-07:00That must be frustrating. The only time I see this...That must be frustrating. The only time I see this is when I've messed up and forgotten to ground the voltage divider and it rises to source voltage. However, there are a couple of possibilities that spring to mind. Did you mix up the commands and turn the XBee pin into a digital input? Is there a capacitor in the circuit somewhere that is holding a charge?<br /><br />If you have a potentiometer handy, put one end on ground, the other at Vcc and the middle to the pin and experiment a bit. That could turn up something that you're overlooking.davehttps://www.blogger.com/profile/11608589214882334649noreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-26221933639363055972015-06-15T12:25:25.198-07:002015-06-15T12:25:25.198-07:00Hi Dave, for one of my projects I was trying to re...Hi Dave, for one of my projects I was trying to read the voltage from the voltage divider to an XBEE Series 2 ADC pin. D1 ADC Option 2.<br /><br />When I connect the Temperature sensor to D1, I get the correct readings, in my case 0.71volts and Analog value 621. However when I connect the voltage divider to D1, multi-meter shows 0.69 volts because i have 9v or 6 AAs. The coordinator xbee does not get the right value, it always shows as 1023 the max value. Appreciate any guidance or suggestions.<br />Thank you! , HG.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-15667309102356177432015-06-05T19:39:26.224-07:002015-06-05T19:39:26.224-07:00It will take longer as you get more devices. As th...It will take longer as you get more devices. As the traffic increases, it take longer for the XBee to fit the message into the mesh, and it may have to retry. However, good job.davehttps://www.blogger.com/profile/11608589214882334649noreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-69016915870558442232015-06-05T19:37:54.008-07:002015-06-05T19:37:54.008-07:00HG, thank you so much for measuring this. I tried ...HG, thank you so much for measuring this. I tried to get one of the meters, but couldn't, so I just played it by ear. It looks like I'm really near the shelf life of the batteries that we buy from the big box stores and such. And, frankly, a year would make me ecstatic.<br /><br />Thanks again.davehttps://www.blogger.com/profile/11608589214882334649noreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-78357906227301160532015-06-05T18:03:04.585-07:002015-06-05T18:03:04.585-07:00In the interest of people reading this post.
Dave&...In the interest of people reading this post.<br />Dave's step up consumes 10 mA when awake and 19.3 micro Amps when sleeping per the eevblog micro current meter. Assuming the AAs give 2700 mHA and you send the reading ones every 5 mins @.92 seconds wake up, the battery should last about 5.25 years !!! Congrats Dave !! <br />HGAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-84884561569300739682015-06-03T10:24:39.104-07:002015-06-03T10:24:39.104-07:00Thank you Dave, this fixed my issue. On another no...Thank you Dave, this fixed my issue. On another note i changed SP = AF0 and SN=15 on the coordinator.<br />After the change the xbee is able to transmit temperature in less than 1 second all steps combined :-)Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-34659889081885091692015-06-03T00:27:43.030-07:002015-06-03T00:27:43.030-07:00Thank you very much, I have this working with SM =...Thank you very much, I have this working with SM =1.<br />With respect to my previous issue to performance, I changed my coordinator to have SP=AF0 and SN=15, now the entire reading is sent in under 1 second :-)<br />HGAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-74123557448741678792015-06-02T22:33:38.874-07:002015-06-02T22:33:38.874-07:00I used SM = 1, but you also have to raise the slee...I used SM = 1, but you also have to raise the sleep pin to knock it out; if I remember correctly, it doesn't go to sleep until you raise the pin. So at init time, set the pin low, do whatever you need to first, then set it low just before you sleep the arduino. When the arduino wakes up, set the pin low and then wait for the CTS pin. If you send too soon, it goes nowhere.davehttps://www.blogger.com/profile/11608589214882334649noreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-81203962718527310512015-06-02T10:44:09.731-07:002015-06-02T10:44:09.731-07:00Hi Dave,
I did some more testing and research, fe...Hi Dave,<br /><br />I did some more testing and research, few folks have already documented the 6 seconds delay.<br />One more testing that i did was to run the XBEE in PIN Hibernate mode SM=1.<br />I was not able to get this to work with SM=1, wanted know how have you configured the xbee connected to the pro-mini?<br /><br />As always - greatly appreciate any inputs from you. Thank you!<br />HG<br /><br /> Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-5296022494487557902015-05-28T15:54:54.542-07:002015-05-28T15:54:54.542-07:00I posted the question there and got a silly answer...I posted the question there and got a silly answer with the suggestion that I contact customer support. That's the problem with these support forums, people answer with, "I don't know". <br /><br />Silly.davehttps://www.blogger.com/profile/11608589214882334649noreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-90432505606100312332015-05-28T15:54:46.509-07:002015-05-28T15:54:46.509-07:00I posted the question there and got a silly answer...I posted the question there and got a silly answer with the suggestion that I contact customer support. That's the problem with these support forums, people answer with, "I don't know". <br /><br />Silly.davehttps://www.blogger.com/profile/11608589214882334649noreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-70272979593164667322015-05-28T15:28:33.887-07:002015-05-28T15:28:33.887-07:00I will post this observation on Digi's website...I will post this observation on Digi's website, will post back if there are new learnings.<br />I was thinking of trying to confine and co-ordinator and the end device to a single channel but that may not help much.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-73100591325150557872015-05-27T12:14:01.574-07:002015-05-27T12:14:01.574-07:00I went the other way. I set mine to fire every 10 ...I went the other way. I set mine to fire every 10 minutes, so the network would have forgotten about it, and sure enough, it took a little over six seconds to connect back up. That was a problem at first since I had it set to go back to sleep in five seconds. <br /><br />I'm going to see if two seconds is normal, but it may be that it's already as short as it can get.davehttps://www.blogger.com/profile/11608589214882334649noreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-49602669271535650622015-05-27T10:48:41.931-07:002015-05-27T10:48:41.931-07:00Just to let you know, I did try to reduce the tran...Just to let you know, I did try to reduce the transmission interval to 15seconds so that the coordinator does not drop the end device, that did not make any differance to the 2 seconds initialization process.<br />Thank you - HG Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-88860651170079997102015-05-26T16:38:03.955-07:002015-05-26T16:38:03.955-07:00I really appreciate your checking this out. This m...I really appreciate your checking this out. This made me think about something I should check out. The time to rejoin is heavily affected by long it's been asleep. If you stay asleep longer than the network timeout, then the coordinator forgets about you and you have to reestablish the connection. <br /><br />I thought I'd taken care of that, but I may have messed it up. Now, I have to check it out and see.davehttps://www.blogger.com/profile/11608589214882334649noreply@blogger.comtag:blogger.com,1999:blog-4922503085503427986.post-88549006214636083082015-05-26T15:01:31.125-07:002015-05-26T15:01:31.125-07:00Thanks Dave - I think I will leaving it running fo...Thanks Dave - I think I will leaving it running for now, was just curious and want to share my findings. HGAnonymousnoreply@blogger.com