question about the new o8m2

[Treehouse]

on the older 08m chips pin 2 (Ser in), is only used for programing and required a 10k and 22k resistor for proper operation. My question is, after programing the new 08m2 pin 2 can be used as an input so does this mean I don't need those resistors ? or how do I use it as an input?

 

[nick12ab]

After programming, the 22k resistor doesn't have to stay, however, you still need the 10k pull-down resistor otherwise if the pin is in the high state when the PICAXE is powered on, the program will not run. The pull-down resistor is not needed if you're interfacing something that can pull down before the PICAXE first checks the pin for a program download.

To use the pin as an input, you need to use the DISCONNECT command and then you can use the pin as any other input. To program again, do a hard reset or use the RECONNECT command.

Also, to avoid confusion, 'pin' is used to refer to the pin in the program (so pin5 is serial in on the PICAXE-08M2) and 'leg' is used to refer to the physical pin (leg 2).

 

[Treehouse]

thanks, so I assume this is the same for all the M2 series chips?

 

[nick12ab]

thanks, so I assume this is the same for all the M2 series chips?

Yes, except for the 20M2 nwhich, according to the datasheet, doesn't support use of the Serial In pin as a general input.

The serial in pin is C.5 on both 08M2 and 14M2 but the 18M2 uses C.4 instead and C.5 is another fixed input.