2009/3/25 Richard <[email protected]>: > > > > port pin b3 (LVP) is now spare input selectable high or low with > jumper. > I don’t know why using pull down resistor else than for safety when > making > b3 output and high, but that would be not smart to do ;-). > > But if you want pull down on port b3 (LVP) or have other ideas please > let me > know, we will discuss them, and if necessary change them. The issue is that if you forget about the lvp configuration bit (or maybe you can't set it since you use a bootloader), a high level on lvp pin will prevent your code from running. So it is not mandatory (you should not forget to reset the lvp bit), but it could prevent someone to run in trouble one day....
> one diode off € 0.02 (1N4148) will make it compatible to any > programmer > and not sensitive for signals or fingers ;-) Good to mention this again. A simpel but effective way to handle this. > for 1-pin interface you need a code to set your backlight like /B100 > is backlight 100% is therfore on and /B0 is backlight 0% is therfore > off > and off course /B50 is backlight PWM 50%. > > Or is this not what you mean? I'm afraid I don't know excactly what you mean... What I intend to achieve is one API to control the backlight. The most important function is lcd_backlight(var bit onoff). This will work regardless the case: digital or variable backlight. And direct connected or via 1-pin serial. And the 'protocol specification' of the 1pin interface should of course be able to handle the backlight control without interfering with lcd control itself. This protocol is not explicitly documented, but quite easy. It consist of sinlge byte commands. Each command is divided into a 3-bit type and 5-bit value. When type = 0, the 5 bit are the rs-value and 4 bit data (nibble). when type = 1, the 5 bit are the pwm value. So pwm works in 32 steps resolution. Joep --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/jallib?hl=en -~----------~----~----~----~------~----~------~--~---
