how can propic2 be converted to support icsp?

[spyghost]

propic2 schematic

hi,

propic2 is a good pic programmer. i have one made in a point-to-point wiring and its works great. the problem here is that it is not icsp yet. you have to program the pic the old-school way of remove it from the target app and place it in the programmer.

in the propic2 website, there is this propic2 icsp which is an icsp version of propic2. if you notice its smaller than the previous.

now i am just wondering can the propic2 schematic in the **broken link removed** be converted into icsp?

the dillema that i am facing right now is that the 13v line actualy comes from 3 independent transistors...

is there a workaround for this? all i wanted to achieve is a propic2 icsp given the existing propic2 schematic

thanks

 

[maneco]

original propic2 schematics

hi,
you could try adding a fourth pnp transistor for switching the 13v to your icsp connector,its base driven by a three input and gate,or three diodes,from the three outpùts of the 7407,so this transistor is enabled when any of the three vpp's are enabled...i don´t have propic2,but does it make sense?

 

[wizpic]

propic2 pic programmer

hi spyghost
I am in the process of modifing the pro-pic to iscp. i do all my designs cabable of iscp. at the moment i use the epic programmer but this is hit and miss some times. so all my designs use the epic header so the easy way to do it is put 3 diodes in line of VPP1,VPP2,VPP3 to your iscp header tehn RB6,RB7,GND and that will work which ever chip you want to program
i am just finshing of the schematic will be done later tonite so i will post it.

hope this helps you
wizpic

 

[wizpic]

propic schematic

Here you go have a look at that it is just the propic vesrion the PSU and gold side is still been done but it shows the ICSP part
there mat be one thing that could go worng is the 0.6V drop across diodes
I'd be interested in anybodys views on this

wizpic
p.s i have done it in protel 2004

 

[spyghost]

74hc07 pic programer

it would still use all three transistors and would employ additional diodes...

referring to the schematic on the site... i had these thoughts... please comment on them...
- i will only use one transistor for vpp
- transistor networks of t4 and t3 would be eliminated, only t2 will remain
- pins 2, 6 and 12 of ic3 would be tied together
- diode,resistor,led network would be removed (vpp1, vpp2, vpp3) and will be replaced by a current limiting resistor and led would be placed at collector of t2

 

[maneco]

propic2 icsp

Sounds like it will work,if the chip is an open collector type...so a 74hc07 won´t work,you'll need to combine the three outputs with diodes in that case...

 

[spyghost]

74hc07 same sn7407

Sounds like it will work,if the chip is an open collector type...so a 74hc07 won´t work,you'll need to combine the three outputs with diodes in that case...

7407 is open collector: https://focus.ti.com/docs/prod/folders/print/sn7407.html

 

[wizpic]

propic 2 programmer

Spygosht
i see where you are coming from in that case then just get rid of all stuff you dont want want. but you still may have to put 3 diodes in-line to prevent feed back on chip and parrell port

wizpic

 

[spyghost]

Spygosht
i see where you are coming from in that case then just get rid of all stuff you dont want want. but you still may have to put 3 diodes in-line to prevent feed back on chip and parrell port

wizpic

hmmm... so even though its an open collector type of output i still need the diodes...? :?

 

[wizpic]

spygohst i will look at data sheet later on and double check to make sure it was just a thought

wizpic

 

[wizpic]

here u are have a look at this one this should do it

wizpic