VDI-RODERICO

[roderico]

Compliments to the bold design ... my suggestions for changes will be given after the prototype and tests in IDX .... a good solution with this SW5 - you can use SW3 to turn on the backlight ... I do not want to power the system with + 8V only with BAT, in IMUT + 8V to be deleted, power the system with BAT

you only have to short pins 2 and 3 of P1 (input) while keeping the 5 pin input to use only 12V, did you use 12V in your current vdi?

[roderico]

with 12V you willneed to dissipate more than twice the power that with 8V, produces moreheat, more noise… but maybe it is negligible for this

[roderico]

depending on your LCD you might also need to replace the 78L05 by a 7805 if using 12V, you could test it in the new prototype for comparison

[kroman01]

I did vdi Lugatek DM-1 and V-Box 2 with the use of LCD AG-128064H-FHW K / W-E6 or EG-128064H-FHW K / W-E6 and enough 78L05 it all depends on the required current to LED backlight

[roderico]

according to the datasheet the supply current for the backlight is 150 mA, you need to add at least another ~10mA, then you will need to dissipate (12V-5V)*160mA = 1.12W with the 78L05 instead of 0.48W if using 8V

[roderico]

in the datasheet of the 78L05 the output current is < 100mA and the power dissipation < 0.7W it won't work well with the backlight...

[roderico]

IMO a good choice would be 7805 with a heatsink if using 12V and without heatsink if using 8V

[kroman01]

displays have a bright background, so they do not require backlighting during the day, only at night do not have to be so bright, I am reducing the LED current of the R11 330R resistor. this is how the "Lugatek DM-1" shines the total current from the 12V 20.5mA power supply .... stabilizer 78L05 system on the ATMEGA8 A-PU 10 MHz clock

[roderico]

that would be the option for the 78L05, it looks very nice. IMO it would be better to leave the 8V pin and make a little room for a 7805 since there is already a regulator in the idx for 8V, and in this way, the pcb can be used with both 12V/8V and with 78L05/7805 for compatibility

[kroman01]

do not change the PCB will be pin + 8V and BAT will decide during construction what to choose ... LCD should be bought with white LEDs in the backlight, everything with a white LED has a maximum current of 20mA, which is too big because at night the eyes are tired and they should be toned down

[chafik]

Why people still doing programme for old chip like 16f84 16f876 or 16f878 or 16f88 they are expensive and they will become obsolete because microchip is introducing new chip with big memory size and cheaper and have the new features microchip is doing that because they are going from assembly to c programming

[roderico]

95% of the code can be reused and you don't need to rewrite the program for every new model, only the specific part. PIC16F886 is in production and it is quite cheap, it would not make much sense to buy a pic with 128KB when you only need 14KB, for a GLCD I would say any pic with 32KB would be sufficient, e.g. PIC18F25K22, however an old model as the PIC18F252 would also work very well... it depends on the availability of the chips and the particular problem

[kroman01]

good for GLCD will be better available PIC18F25K22 and cheaper as PIC18F252

[roderico]

if you are going to buy a new one you better buy a PIC18F25K22 without any doubt, PIC18F252 is not in production only in case you already have one

[roderico]

also PIC18F2520/2523 would be fine but preferably PIC18F25K22 (no need to say that they will also work with the LCD)