I want to interface a PIC 18F877 with a GSM Modem. Can I interface with the modem through a terminal program? Anyone ever interfaced a modem like this with any type of micro-controller?
Dig
Hi Dig,
Is there a reason you are looking at using the 16f877? The most common interface for GSM modules is a usart and from memory I'm pretty sure that the 16f877 only has one hardware USART, whilst not show stopping it means that you will need to bit bang either the modem interface or the PC interface and means you have less resources available for anything else you are needing to impliment. You might want to consider using a later Pic variant with 2 uarts or even USB.
Have you got a GSM module in mind?
Again the ones I am familiar with use either a variant of the Hayes command set, which it really easy to use, or a proprietry data protocol. Still not too difficult to use but will require more time pouring over datasheets. So yes, in some cases you can talk directly to the modem but it is very hardware dependant. Oh and dont forget the Pic is a 5v device and a lot of the newer GSM modules are 3.3v only so you need voltage translation, its a terrible thing to watch the smoke escaping 
If you want to provide more info on the project I would be happy to discuss it with you further, or drop an email to techsales@farnell.com and mark it for my attention.
Hi Dig,
Is there a reason you are looking at using the 16f877? The most common interface for GSM modules is a usart and from memory I'm pretty sure that the 16f877 only has one hardware USART, whilst not show stopping it means that you will need to bit bang either the modem interface or the PC interface and means you have less resources available for anything else you are needing to impliment. You might want to consider using a later Pic variant with 2 uarts or even USB.
Have you got a GSM module in mind?
Again the ones I am familiar with use either a variant of the Hayes command set, which it really easy to use, or a proprietry data protocol. Still not too difficult to use but will require more time pouring over datasheets. So yes, in some cases you can talk directly to the modem but it is very hardware dependant. Oh and dont forget the Pic is a 5v device and a lot of the newer GSM modules are 3.3v only so you need voltage translation, its a terrible thing to watch the smoke escaping
If you want to provide more info on the project I would be happy to discuss it with you further, or drop an email to techsales@farnell.com and mark it for my attention.
