Inchworm components

[William At MyBlueRoom]

Hmm, very few components for the communications part. Can you post or email me a color photo of your assembled board? I can handle large attachments with this account. Since you had problems with your WISP, it could also be the serial port. It's tough to test the crystal without a scope...
support@blueroomelectronics.com

 

[Sig239]

I have installed version 7.51 and the OS is ICD04020701.hex. Is this OK to download, and when I turned of FIFO buffers windows did not prompt for a restart.
EDIT: Ohh and I forgot, How can I tell which COM port it is hooked up to.

 

[3v0]

When I built my Inchworm about a month ago I suggested to DipMicro that if they were going to supply parts different from Bill's instructions that they should provide a note regarding what the subs were.

I had no problems with DipMicro. It did take a bit longer to get the kit in the US due to customs.

My Inchworm has worked fine from the first time I fired it up.

3v0

 

[Sig239]

So far mine is working fine (at least all the voltages check out so far) I just need to get it to communicate with MP labs. I'm sure it will work fine. Maybe there needs to be total step by step for hooking it up and communication for us newbs.

UPDATE: I have successfuly connected. I couldn't find the proper firmware version until I manually selected the 16f877 part....duh anyways, now I just have to get something to program with it!

 

[gregmcc]

Bill,

I've email you a pic of my inchworm. I've tried a few more things - reinstalled mplab, tried another pc and also another rs232 cable - no luck.

I've used a scope and had a look at the pic - the crystals working, and there are some signals going from the rs232 chip into the pic. anything in particular i should look out for?

 

[3v0]

RS232 Loop Back

Loop back test for the RS232 section of the Inchworm.
--------------------------------------------------------

These instructions are for the people who are new to electronics.
Read, understand, and follow these instructions while I poke my finger in my eye. Please understand what this test does prior to doing it. It is not a learn as you do sort of thing. I do not want you to ruin your inchworm. Proceed at your own risk.

1. Remove the 16F877(A).
2. Hook the Inchworm to the PC with the serial cable.
3. Start hyperterm, select the correct com port.
4. Power up the Inchworm.
5. Note that when you type in hyperm window, nothing happens.
6. Jumper pin26 RX and pin25 TX on the PIC socket. ***
7. Type in the hyperterm window, you should see what you type.

If Hyperterm displays what you type with RX and TX jumpered and does not without the jumper.... then your RS232 cable is OK and the MAX232 is doing its job and providing TTL level ASCII to the PIC socket. This is good.

Problems
---------

If Hyperterm display the keys witout the jumper in place you have a short between RX and TX either before the MAX232 or between it and the PIC. Rare.

If Hyperterm does not display the keys with the jumper in place first check to see if maybe you have a good non-null-modem RS232 cable. Use an ohm meter to do this. Cable pins 2 and 3 should conduct and not be crossed.

If the cable is good you need to troubleshoot the RS232 section on the Inchworm. I will leave that to Bill.

*** Do NOT force a large wire into the PIC socket as if it were a breadboard. That would ruin the socket. Just hold the wire against the pins. If you can not type and hold the wire at the same time have some one else do the typing.

HTH
3v0

 

[3v0]

RS232 Loop Back

Loop back test for the RS232 section of the Inchworm.
--------------------------------------------------------

These instructions are for the people who are new to electronics.
Read, understand, and follow these instructions while I poke my finger in my eye. Please understand what this test does prior to doing it. It is not a learn as you do sort of thing. I do not want you to ruin your inchworm. Proceed at your own risk.

1. Remove the 16F877(A).*
2. Hook the Inchworm to the PC with the serial cable.
3. Start hyperterm, select the correct com port.
4. Power up the Inchworm.
5. Note that when you type in hyperm window, nothing happens.
6. Jumper pin26 RX and pin25 TX on the PIC socket. ***
7. Type in the hyperterm window, you should see what you type.

If Hyperterm displays what you type with RX and TX jumpered and does not without the jumper.... then your RS232 cable is OK and the MAX232 is doing its job and providing TTL level ASCII to the PIC socket. This is good.

Problems
---------

If Hyperterm display the keys witout the jumper in place you have a short between RX and TX either before the MAX232 or between it and the PIC. Rare.

If Hyperterm does not display the keys with the jumper in place first check to see if maybe you have a good non-null-modem RS232 cable. Use an ohm meter to do this. Cable pins 2 and 3 should conduct and not be crossed.

If the cable is good you need to troubleshoot the RS232 section on the Inchworm. I will leave that to Bill.

* Check the PIC for bent pins. If either pin 25 or pin 26 is bent under you may have found your probloem.

*** Do NOT force a large wire into the PIC socket as if it were a breadboard. That would ruin the socket. Just hold the wire against the pins. If you can not type and hold the wire at the same time have some one else do the typing.

HTH
3v0

 

[William At MyBlueRoom]

That's a good idea 3v0 I was thinking of something along those lines the other day. Trying to use the busy LED as an indicator when the PIC is out of socket. Perhaps flea-clips might be handy.
The difficult part is it can also be the serial port on the users PC. Although internal serial ports tend to be fine the USB to RS232 can be wonky, example is the common PL-2303 based adapters. The default driver may not work but a 3rd part driver will. (I have an example of this on my site).

To connect to the inchworm you only need CON2, P1, U1, U2, U3, All caps, R18, D1, D2, D7, D8 and the crystal

If you have a scope and the crystals running that's a good start. A second PC is also handy to eliminate the PC as a cause of problems

Nice too would be a simple PIC programmer but since the Inchworm is a programmer that's unlikely.

It would be nice if there was a program that let you toggle the CTS, RTS, DTR lines.

 

[3v0]

The difficult part is it can also be the serial port on the users PC...

A handy thing to have around is a loopback DB9, just a female DB9 with pins 2 and three jumpered together.

Plug it into the PC and you can loopback test the PC.
If that works attach the RS232 cable to the PC and and plug the
loopback DB9 into the other end. This tests the cable.

The user still has to make sure he is not using a null modem cable.

I am just starting to work with USB hardware and drivers. Regarding them I am mostly clueless at this point. Is there any reason that the loopback DB9 would not work to verify a USB to RS232 converter ?

3v0

 

[gregmcc]

3v0 - I tried testing the serial comms as you suggested - it works fine. I've already tried a 2nd PC - same problem

Both machines have internal serial ports.
I've justed tried it again using another power supply - just in case. No difference.

Really running out of options - tried 2 machines, 2 cables, 2 power supplies.

 

[3v0]

At this point I must refer you back to Bill.

It is his project and I am sure he has a much better idea of what to look for.

3v0

 

[Nigel Goodwin]

3v0 - I tried testing the serial comms as you suggested - it works fine. I've already tried a 2nd PC - same problem

Both machines have internal serial ports.
I've justed tried it again using another power supply - just in case. No difference.

Really running out of options - tried 2 machines, 2 cables, 2 power supplies.

This really leaves the obvious conclusion that the PIC isn't working, either a connection problem, or the PIC isn't actually programmed with the boot loader?.

Probably the next option is to check the PIC is programmed?, and you need something to read it with - such as a PIC programmer. Do you know anyone nearby who has a PIC programmer?.

 

[Sig239]

Hello gregmmc it looks as if you are having similar problems to what I was having. For me hardware was not the problem. Go into MP labs >configure>select device and make sure it is showing 16f877, by default it was showing a 18f... device. This will allow you to select the proper OS. I could not connect until the OS was downloaded. I hope it helps.

 

[gregmcc]

Sig239 - your a genius!!! Its working!!

I had some other pic selected. Selected the 16f877 and uploaded the OS - boom - its working! Shows all the right voltages as well.

Thanks for all the help guys.

 

[Sig239]

Great! I'm glad it helped. MPlabs has the 18f device selected by default.

 

[William At MyBlueRoom]

Great! I'm glad it helped. MPlabs has the 18f device selected by default.

I'll be darned. Amazing. I'll put that in the manual... (Done it's there with a credit to Electro-Tech-Online)

Such a great tip Sig239. Can I send you your choice of a Inchworm, Firefly or Robin PCB?

 

[Sig239]

Really, Wow! You certainly don't have to do that, but I will let you! A firefly board would make for a pretty sweet ZIF adaptor (after I get the ZIF socket of course) for the programmer!

 

[blueroomelectronics]

Sure Email me with your address. Yep I'm changing to blueroomelectronics from William at MyBlueRoom.
bill@blueroomelectronics.com

 

[Sig239]

E-mail sent... Silly me forgot to fill in a subject...If you don't get it I'll resend with a proper subject line. thanks again!

 

[gregmcc]

A really usefull tip - I was just about to replace the pic. Fired up the hello world test program - works like a charm.