Arduino SMS Temperature Alarm Controller for Aquariums etc. - Page 1
Forum section: electronics / general

author: picandmix
author_rank: Frequent Contributor
timestamp: July 23, 2015, 09:49:34 am
content: An Arduino based SMS Alarm unit using a DS18B20 sensor with up to 4 other inputs for things like float switches etc etc.Designed for Aquariums but sure it can be adapted for other uses.

author: Wilksey
author_rank: Super Contributor
timestamp: July 24, 2015, 01:41:50 am
content: Not a bad effort!Few things I would say, AT+CMGF, in your comments you state is "AT command to send SMS message", you may already know, but this actually sets the mode, PDU or TEXT AT+CMGF=1 sets TEXT mode.I notice you do not issue a AT+CMGD, which will delete the SMS messages after you are done, a AT+CMGD=1,4 should do the trick, otherwise the SIM will get backed up with old messages and eventually reject them.Perhaps of no interest to you, perhaps it is, but thought I would mention in case anyone else were to use your projectAlso, are you sure that the 900A requires a lot of modification (you state in your report), I am no expert with these modules, and haven't looked into them in detail, but i'm sure the 900A is just a dual band version of the 900 (quad band)? What kind of modifications are required?

author: picandmix
author_rank: Frequent Contributor
timestamp: July 24, 2015, 08:47:17 am
content: Quote from: Wilksey on July 24, 2015, 01:41:50 amNo, I really appreciate your helpful input, both C++ and the AT commands are new areas for me; I only had those online tutorials to guide me.Will have to make a AT / Sim test bed and check out / experiment with those AT commands more, though as you know better than me, there are a lot of them !QuoteSeems the 900A modules are not yet available on a Arduino Shield style of board and more importantly that they are software locked to only operate in certain Far East areas.Seems you can reprogram them with the 900 firmware, but thats perhaps not something most folk would want to try ?http://www.instructables.com/id/Using-a-SIM900A-GSMGPRS-module-in-Australia/?ALLSTEPSAm awaiting one of them to try out this mod to see how practical it is.That board is also minus the 4v regulator the standard 900 Shield has, so an additional parts would be needed, be it another buck converter or dropper diodes.Will post an updates folder when I have tested and added your corrected AT commands.Many thanks.

author: Wilksey
author_rank: Super Contributor
timestamp: July 24, 2015, 10:48:46 am
content: Hi,Yes, I have developed a ton of projects using GPRS/3G modules,http://imall.itead.cc/im140318007.htmlSeems that they are available with both.The SIM900A won't work on the UK networks in anycase, but someone might find this link useful:http://www.blog.zapro.dk/?p=368A 3.7 / 4V regulator and a decent cap would suffice for the PSU, I have gotten away with 4 x 330uF and 2 x 470uF in the past, I designed on that ran from the USB, limited to 0.5A at 5V, that was fun, I used a 40mF 5.5V capacitor and pre-charged before turning on the regulator.

author: charlespax
author_rank: Regular Contributor
timestamp: July 28, 2015, 07:48:16 pm
content: I'm trying to do something similarvia old Nokia phonesthat use the F-Bus protocol. It's a learning experience, but I'm getting there. Just be thankful that you get to use AT commands.