Hi, can anyone think of any reason why my olimex icd2 works when i connect to the 40pin dip version of the 18f4550, but not the smt 44-tqfp version?
I have a professionally manufactured 18f test board with a 44 pin smt pic on it, but the icd2 wont connect. MPLAB allways says that wrong target ID is connected.
I have tested and retested the ICSP connections, all are fine.
Ive got a schem of my board, but not the of the other one.
This is my first go at smt pics, its not going well!
Ive basically just soldered on the pic and a ICSP header, and soldered on the (bottom pcb side) blue jumper wires.
This is allways the first thing i do when i make a new board. If the ICSP doesnt work, then somethings not right.
MPLAB doesnt recognise my board, or the other pro. one. If i connect up a previous project (uses a 4550 40pin pdip) and i can get the stupid olimex programmer to work, then MPlab connects without problems.
Please tell me im doing something foolish, i just cant work out why it doesnt work.
Ive trashed three 4550's on several copies of my board, i kept thinking that i had ruined the chips through ESD.
Lucky ive got my trusty (if not slightly vulgar) AOYUE rework station.
Anyway ive now come to the conclusion that the chips are ok.
everything in the schem s unconnected, just the pic and the icsp are soldered to the board.
Hi Herbert
Did you notice the schematic and Layout, at pins 28 and 29. I fear, Vdd is shown connected to Gnd and Vss to 5V as per the schematic? It should be otherwise I feel. Same is the case with pins 6 & 7. please check .
This will sort it out.
This doesnt explain why the Professional board doesnt work, but i really dont care as long as my boards work.
Does anyone know if the dedicated ICSP port has to be turned on before use (i.e config bits)?
If it does, it strikes me as slightly foolish, having to config the pic using legacy ports first.
Happy that the Chip is ALIVE with all the trouble it had with reverse polarity. Thanks for the compliment-- there is nothing about it. i looked at it with open mind and with no prior bias in my mind while looking at the problem.
You are lucky that the chip is working.
Thanks again
Happy that the Chip is ALIVE with all the trouble it had with reverse polarity. Thanks for the compliment-- there is nothing about it. i looked at it with open mind and with no prior bias in my mind while looking at the problem.
You are lucky to to save the chip.
Thanks again
Herbert, I wold not used the word "closed Mind" but perhaps you might be under tension about why NOT of the issue. this tension is what I claimed not in my mind while looking at the diagram. That way I am with you burning a 18F2550 while trying to program it. These things happen now and then-BTW, Try to purchase a Hot Air Gun to prevent further damages to chips. you can save a lot. If you come across a chinese model it won't be costly and with little practice , it serves well.
Herbert, Try to purchase a Hot Air Gun to prevent further damages to chips. you can save a lot. If you come across a chinese model it won't be costly and with little practice , it serves well.
Ive got a crude AOYUE rework station. Its just my first time using it! I roasted a few chips, and almost burnt a hole in one of my boards! pratice makes perfect i suppose.
Ive got a crude AOYUE rework station. Its just my first time using it! I roasted a few chips, and almost burnt a hole in one of my boards! pratice makes perfect i suppose.