hi,
Look at the 3 DATA line points, when you VERIFY a PIC, the PIC drives the DATA line, which if you used a 4069 would be held at an active High or Low by the program. This will cause problems.
Use the correct chip types as specified in the circuit diagram.
Just get a few 74ls06 or 7406 chips and keep your circuit true to the original design, as already mentioned these programmers, built as specified, can be tempremental at times
O.K, I am going to switch back, then. ( I haven't taken the risk of connecting the programmer to the PC yet)
I at first thought that CMOS, were superior than TTL s (higher Fan outs, Lower power cosumption and Higer price). So I thought that TTL was used just for the lower price as the other benefits aren't required.
I am learning how I was wrong.
I don't think you were right here. I bought a brand new dm7406. Suplied just powers through 7805 (whose input is 13volts). It (7805) consumed damn 33mA at 13v. I drove a led through 1 of the gates. It (7805) consumed 45mA.The datasheet also lists 30mA as a typical supply current.
I connected the programmer to the PC. The oshonsoft (https://www.oshonsoft.com/picprogparallelsetup.exe) programmer software seemed to work fine. When I enabled and disabled the Vdd/Vpp line by using the Hardware Check Freature of the software, the Leds responded correspondingly.When I programmed a simple program, It said, Chip Programmed. But When Verifying, it Said " Verification failed. Expected data 102A, Obtained data: 3fff." I even checked the PIC on breadboard, to see if it was programmed, but No.
Anybody interested to say what might be at fault?
Have you tested all the lines from the Software ? Vdd,Clock, Data as well as Mclre.
You should see over 4v on the clock and data lines and 5v on the Vdd.
You do not specify exactly what capacitor you are talking about - adding parts at random, particularly caps, will more than likely create more problems.
Hi,
Have you tested all the lines from the Software ? Vdd,Clock, Data as well as Mclre.
You should see over 4v on the clock and data lines and 5v on the Vdd.
You do not specify exactly what capacitor you are talking about - adding parts at random, particularly caps, will more than likely create more problems.
Yes I tested every (five) pins of the socket. Vdd, Clock (PGC), Data (PGD) are 4.8 to 4.95 Volts (when enabled through software). Vpp is 13.2 Volts. Vss is few milivolts i.e. effectively 0.
I was taking about putting small cap (150pF) in between the PGC and Vss terminals of the socket. But I don't know how it will help or if at all.
As for adding 150pf just to the C line ? - no reference ?
You might be better getting hold of a pic chip that has already been successfully programed and seeing if you can Read that in via the programmer - at least that will show if the circuit is working in part.
Would think someone at your college can help there ..
Hi,
You might be better getting hold of a pic chip that has already been successfully programed and seeing if you can Read that in via the programmer - at least that will show if the circuit is working in part.
Would think someone at your college can help there ..
I don't think it will help.
Well, I think the programmer can't write in the first place; because, a simple LED blinking program was written to the PIC, and then the PIC was tested in breadboard to see if it blinks the LED, but no.
Are you aware that the software can control the LEDs through its Hardware check feature?
Also, the software finishes programming a 210 byte simple Led blinking program in fraction of seconds , is this normal?
I thought that: if the "parallel port's Ground" wasn't connected to the "programmer's ground" then the software wouldn't have been able to control the LEDs.
Anyway, I am ready to do anything.
I thought that: if the "parallel port's Ground" wasn't connected to the "programmer's ground" then the software wouldn't have been able to control the LEDs.
Anyway, I am ready to do anything.
Thanks for that. I have attached the hex file and the C file of the LED blinking program. There is a little input and conditional statement too!
I am using PIC16f877A.