Sariel, I have a few ideas on what may be causing your difficulties with some of the cables but I need some more info from you to confirm them. The long cable with the 4 jumpers may be a problem because of the jumpers. If the jumpers are on the '595 side of the tester three of the 4 pins will be shorting the signal on the fourth pin to ground.
Referring to the three cables in the attached diagram, cable A can be tested. Cable B, which is cable A reversed could not be tested since 2 of the 3 connected pins would be connecting the third pin to ground. Cable C could not be tested in either orientation since it would not have an input signal to the jumpers in the orientation shown, and is not connected to the '165 inputs if reversed. A tester could be built to test cables like this but it would be quite a bit more complex.
Propeller EMP-11 SIMM Tester.zip I saw this posting yesterday and I thought I might be able to modify it to fit my needs for testing the Family Modules for the Needham's Electronics
Programmers. The file I sent is for the EMP-11 which has 30-pins. I also want to do one for the EMP-20 if this works (80-pins). Manually checking each pin connection got old very fast.
I'm new to Propellers so please bear with me. Am I barking up the wrong tree? Thanks
No you are not barking up the wrong tree. At the moment I am working on a tester to check the wiring that connects several modules mounted/wired in a cabinet.
Unfortunately the file you sent is not much use without the software that uses it. I am guessing (based on the info at the Needhams web site) that you want to check the connections between a chip socket of some type on top of a module and the connectors on the bottom of the module that are used to plug the module into a base unit. Something like the adapters on an eprom programmer. If this is the case a block diagram with the total number of connections at the chip socket and base unit connectors would be helpful.
Propeller EMP-11 SIMM Tester(NP ver).zip The file I sent is from DipTrace. One can purchase it here on Parallax's Site. I have the Non-Profit version which one can start with the free option. If it says that the project has too many pads let me know and I will take out some of it so everyone can see it without having to purchase it. What I'm trying to compare are the Modules that one installs on the programmer that are
SIMM like PCBs with traces on them to different pins depending on the IC one is trying to program. These programmers are no longer sold and the needhamsprogrammers yahoo group are trying to document the circuits on these PCBs
to allow everyone to program all the devices the various machines are capable of.
I have the freeware edition version 2.1.0.7 but can not open either of the files you posted. I get a “file format is incorrect” message. Perhaps you can print the schematic to a PDF file and post it. No problem though, I am pretty sure I understand what you are trying to do.
From post 35 it sounds like you have “simm like” modules that plug in to the programmer and routes a number of signals from the programmer electronics to the programmer socket and you want to automate tracing these connections. This is essentially what the unit I helped Sariel with did, and it should work for your application if there are only wired connections (no resistors, capacitors, diodes, transistors, etc) in the modules.
There are two approaches you can take to building this tester. The first is to build it similar to the one described in this thread. That will require one TPIC6595 (or a 74HC595 and a ULN2803), 8 pullup resistors, and one 74HC165 (or 74HC597) for every 8 pins to be tested. That would mean 4 TPIC's and 4 '165's for your 30 pin module, and 10 of each for the 80 pin modules.
The second approach (and the one I am using for my tester) is to use one propeller chip for every 24 pins with a current limiting and pullup resistor on each pin to be tested.
I would be happy to help out with either approach if you decide to go ahead with the project.
OK, it looks like you have an early version of the tester that used '595's to output a bit to each pin sequentially. The problem with this design was that all of the outputs were always enabled (one high, the rest low or vice-verse). If you had any pins jumpered together you were shorting the high and low outputs together. The way we got around that was to use a TPIC6595 with pullup resistors instead of the 74HC595. Essentially the TPIC is a combination of a '595 shift register and a ULN2803 driver in one chip. The outputs of the TPIC are 8 transistors with the sources grounded and the drains connected to the output pins. That means one output can be pulled low and any other output that is jumpered to it will also be pulled low.
Programming the propeller to determine the connections is pretty straight forward.
Setting each pin as an output low in turn:
1 - Clear the TPIC register (optional).
2 - Set the data input to the TPIC serial register to 1.
3 - Shift the data bit into the TPIC serial register.
4 - Set the data input to the TPIC serial register to 0.
5 - Shift the serial register to the output register.
6 - Call the serial input/evaluate connections routine.
7 – Go to step 3 and loop as many times as there are pins to check.
Read the input pins and evaluate connections:
1 - Load the data into the '165
2 - Input the data bit.
3 - If the data bit is 0 note pin as connected to output pin.
4 – Shift the next data bit out from the '165
5 - Go to step 2 and loop as many times as there are pins to check.
I am unable to upload files so if you want schematics using the TPICs PM your email address to me and I will send them to you.
Comments
Referring to the three cables in the attached diagram, cable A can be tested. Cable B, which is cable A reversed could not be tested since 2 of the 3 connected pins would be connecting the third pin to ground. Cable C could not be tested in either orientation since it would not have an input signal to the jumpers in the orientation shown, and is not connected to the '165 inputs if reversed. A tester could be built to test cables like this but it would be quite a bit more complex.
Programmers. The file I sent is for the EMP-11 which has 30-pins. I also want to do one for the EMP-20 if this works (80-pins). Manually checking each pin connection got old very fast.
I'm new to Propellers so please bear with me. Am I barking up the wrong tree? Thanks
No you are not barking up the wrong tree. At the moment I am working on a tester to check the wiring that connects several modules mounted/wired in a cabinet.
Unfortunately the file you sent is not much use without the software that uses it. I am guessing (based on the info at the Needhams web site) that you want to check the connections between a chip socket of some type on top of a module and the connectors on the bottom of the module that are used to plug the module into a base unit. Something like the adapters on an eprom programmer. If this is the case a block diagram with the total number of connections at the chip socket and base unit connectors would be helpful.
SIMM like PCBs with traces on them to different pins depending on the IC one is trying to program. These programmers are no longer sold and the needhamsprogrammers yahoo group are trying to document the circuits on these PCBs
to allow everyone to program all the devices the various machines are capable of.
From post 35 it sounds like you have “simm like” modules that plug in to the programmer and routes a number of signals from the programmer electronics to the programmer socket and you want to automate tracing these connections. This is essentially what the unit I helped Sariel with did, and it should work for your application if there are only wired connections (no resistors, capacitors, diodes, transistors, etc) in the modules.
There are two approaches you can take to building this tester. The first is to build it similar to the one described in this thread. That will require one TPIC6595 (or a 74HC595 and a ULN2803), 8 pullup resistors, and one 74HC165 (or 74HC597) for every 8 pins to be tested. That would mean 4 TPIC's and 4 '165's for your 30 pin module, and 10 of each for the 80 pin modules.
The second approach (and the one I am using for my tester) is to use one propeller chip for every 24 pins with a current limiting and pullup resistor on each pin to be tested.
I would be happy to help out with either approach if you decide to go ahead with the project.
Programming the propeller to determine the connections is pretty straight forward.
Setting each pin as an output low in turn:
1 - Clear the TPIC register (optional).
2 - Set the data input to the TPIC serial register to 1.
3 - Shift the data bit into the TPIC serial register.
4 - Set the data input to the TPIC serial register to 0.
5 - Shift the serial register to the output register.
6 - Call the serial input/evaluate connections routine.
7 – Go to step 3 and loop as many times as there are pins to check.
Read the input pins and evaluate connections:
1 - Load the data into the '165
2 - Input the data bit.
3 - If the data bit is 0 note pin as connected to output pin.
4 – Shift the next data bit out from the '165
5 - Go to step 2 and loop as many times as there are pins to check.
I am unable to upload files so if you want schematics using the TPICs PM your email address to me and I will send them to you.