Serial Buffer RSB509B

[zgaby70]

Hi,

I am planning to use a RSB509B with a 28X1 Picaxe.
For what I have read in datasheet it perfect for my application.
Is somebody here who already have used this serial buffer with PICAXE?
I will like to check if this IC is really working with PICAXE before I order.

Thank you
Regards,
Gabriel

 

[BeanieBots]

Nice find. Looks like it should work well.

However, you do know that the 28X1 can do background serial into scratchpad.
That chip would be great for the 'lower' PICAXEs which don't support background serial.

EDIT:
and welcome to the forum.

 

[Technical]

As BB points out this chip is not required with the 28X1 - just background receive the data into the scratchpad and process it when you need to - see hsersetup command.

 

[zgaby70]

Hi,
Thank you.

This was quick reply. I am already using 28X1 background serial (hser) for receiving data from a barcode scanner.
RSB509B looks nice, I am not sure about how to send/receive data ussing same pin on PICAXE. In datasheet is a sample for BasicStamp II using one pin to send data (serout) and same pin to receive data (Serin).

Regards,
Gabriel

 

[hippy]

Looking at the datasheet the RSB509B isn't that suitable for use with high-speed serial input.

The basic principle is issue a pulse then turn the pulse off and 52us later data will arrive from the RSB509B. To get fast turn-round the trick used on the Basic Stamp is to issue a HIGH then issue a SERIN which makes it 'low' and an input ready to receive data. That should also work with a PICAXE but would need to be tested.

Doing the same with high-speed serial is far more complicated and likely not worth the effort as background serial largely does what the chip itself does.

I'd guess the RSB509B is a programmed PICmicro 12F509, right down to the 22K serial resistor. The lower diode clamp on the TICkit circuit seems to be the wrong way up. There are a number of datasheets and circuits on the site and not all show that diode.