NeoSWSerial | Efficient alternative to SoftwareSerial | Wrapper library

It is bit tough to make arduino request for two URLs as we would have to handle two separate request and its responses, either the two request would merge in and wont obtain required result or the code would become large that arduino-uno wont be able to handle.

So i found an easy way for doing that, i.e to request for the second PHP page from the first PHP page (which is requested by arduino itself). The only difference between these two request was that the second one need an extra variable. I passed along with the first request so it was available for making request from first page.

I changed arduino code as follows :

1. First I modified the portion making the check - just after the displayinfo();, as I mentioned in the question, added a flag bit to it. So it become like this :

Normally, I would have suggested AltSoftSerial as the alternative to SoftwareSerial (read more here), but it also conflicts with the Servo library's TIMER1 use. It can only be used on two specific pins.

I think my NeoSWSerial would do the trick. It re-uses the micros() clock (TIMER0) and Pin Change interrupts to implement a software serial port. This limits it to bauds rates 9600, 19200 and 38400, but it is much more efficient than SoftwareSerial. It can be used on any two pins.

I would not suggest using a software serial port at 115200, as it can be unreliable above 38400. You might be able to send a baud rate configuration command to the NFC module to set it to a lower rate.

BTW, if you are sending information (not just receiving), all software serial port libraries disable interrupts during transmission, except AltSoftSerial... which you can't use. Just be aware of that, because it may affect your Servo when you transmit on NeoSWSerial.

Also, be sure you are using one of the PWM pins for the servo. If the Servo library is creating the PWM signal with software (just like a software serial port), the CPU won't have time for much else.

It might be better to put the NFC module on the hardware serial port, Serial. For debug prints, use NeoSWSerial connected to a TTL Serial-to-USB converter. Then open the Serial Monitor on that converter's COM port. Remove the debug later, because transmitting disables interrupts.

There are other boards that have additional UARTS. For example, an Arduino Leo (ATMega32U4 MCU) has an extra serial port, Serial1, that you could use for the NFC. Serial would still be available for debug prints.