SIM800L Alternatives

[Suraj143]

Is there any better GSM module over SIM800L modules? I encountered so many issues with it & planned not to use it again.Anyone has someother modules which can use in the industry...!!I only need CALL& SMS functions.

Thanks

 

[Nigel Goodwin]

What issues did you have?, I suspect you'll probably have similar issues whatever you use, as you're probably using them poorly.

 

[Suraj143]

What issues did you have?, I suspect you'll probably have similar issues whatever you use, as you're probably using them poorly.

1)Unfamiliar UART level convertion, How did you connect it to the PIC? whats the supply voltage of the PIC?
2)What type of antenna did you used?

I powered the PIC with 3V3 & connected directly the UART.I put a 1K on PIC TX side.Problems down to half way mark.I am powering the module using LM2596 buck modules @4.2V

But still the modules not stable in factory environment.

 

[Nigel Goodwin]

Just resistiors for level conversion, aerials are to a socket, so plug in what you want - for testing I use the little crappy PCB aerials than often come witth them.

With all such modules supply is critical, I use 1F super capacitors on their supply.

 

[Suraj143]

Just resistiors for level conversion, aerials are to a socket, so plug in what you want - for testing I use the little crappy PCB aerials than often come witth them.

With all such modules supply is critical, I use 1F super capacitors on their supply.

Nice info.Now I would also like to add a super capacitor & check. Just searched one, see whether you using a similar one..!!

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Also. what is the. PIC supply voltage of yours?

 

[Nigel Goodwin]

I power the PIC from a 3.3V LDO regulator.

Here's a partial circuit, for the SIMM, not the latest one though.

 

[Suraj143]

Many thanks.Now I got what you doing.You have another 1000uF cap near the SIM800L module power pin & the super cap is powering the FETs.

1)Is that your SIM800L not run always?It will be turn ON when you want..?

2) Why did you take the SIM800L reset pin?When are you reseting the module?

 

[Nigel Goodwin]

The module is turned off almost all the time, usually only turned ON once a week - I hold it in reset as power is applied, and then release the reset pin once the supply has settled.