I will re-check the related changes
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Ok thanks îve bought also a new sim900 Shield
I’ll test as soon as possible
Thanks for your support
Best regards
hello, I received new sim900 shield; reinstalled also librairie downloaded from blynk.com, but looks to be still V0.5.1 version…
I installed also a devise to adapt serial port. I mean, SIM900 operated in 3.3V on bus, but mega 2560 operates to 5V. With this device, I transfor 5V bus to 3.3V . More safety I believe
anyways now it works but not perfectly. Globally it’s not reliable, I mean, it can work 2 hours quite good but after, it can be so long (more than 20s to update). I don’t understand where is issue. also, I have feeling in evening, it becomes very long. How to understand where is issue? How to optimize this? How to diag?
Thanks for your usual support
Just to note you: This IS the latest version of Blynk lib. As for latest TinyGSM just look for “releases” on @vshymanskyy git.
Can you post a link to the SIM900 ‘shield’ that you’re using?
Pete.
Hi, bought on amazon https://www.amazon.fr/SIM900-Quadri-bande-Fréquence-Développement-Arduino/dp/B01F3IA00S/ref=sr_1_1?ie=UTF8&qid=1522502684&sr=8-1&keywords=sim900 thanks for your return
ok thanks
Again mu second shield is down. It ran about 2 days, and now it looks broken, but in different mode. This morning it ran quite good with my mega 2560 using blynk (temp and pressure monitoring), but now impossible to connect to network, software mentions “cannot init” on serial port. On shield, network statut LED is off… several reset, nothing works. Do you have a good shield with good quality to buy?
You mean physically broken/burnt? Or bricked?
Yes, something is wrong with hardware…
What makes you think that the shield works on 3.3v logic levels? As far as I’m concerned they require 5v logic to operate correctly.
These shields also require an excellent power supply - often more than the Arduino can consistently supply - hence the external power connector. If you don’t supply it with around 2A then you’ll have problems.
Pete.
Yes, BE SURE to not power the arduino from USB socket.
Yes I operate with external power source, able to give more than 2 amps with 5V. Then I read on internet, SIM900 operates in 3.3V, then port are directly connected to chip on board, for me it’s better to use 3.3V for UART. Do you agree?
Yes, It’s ok already done
What’s SIM900 shield will you buy you’d me in my place? Is SIM800 better in quality?
Yes, I’d buy SIM800 now, but about quality… Hard to tell. Yours looks quite solid. Mine is an old, dual board (stacked) and can’t see it already available.
From this link:
http://www.rhydolabz.com/wiki/?p=736
Quote:
“This modem can operate at both TTL 3.3V and 5V Logic Level hence making it suitable for controllers at 5V logic level (PIC, AVR) as well as for 3.3V controllers like ARM based controllers and while interfacing depending upon the controller’s logic level we should give appropriate voltage to the V_interface pin of the modem like 3.3V or 5V(should be in the range 2.5-6V) and power the modem with supply range(5V-12V).”
Pete.
OK, @gg09 to summarize:
- SIM900 works fine with 5V logic. I was always using it stright-connected.
- MY BOARD is powered from integrated voltage converter, where on output it provides 4,2V (Yes, that strange). So I’m always using external 12V 1A (or more - depends what’s currently “at hand”) power supply. This a non linear buck converter so it “converts” current too (a high efficiency PSU). How is your board powered? What is the expected Input/output voltage? I don’t see any coil on it, so I’m expecting some linear voltage regulator, possibly some LDO.
Check your voltages first, as I’m not sure if the 5V PSU is the correct one for this Board.
That’s what I use and it works fine. Here’s the wiki for the board:
http://www.geeetech.com/wiki/index.php/Arduino_GPRS_Shield
Pete.