Programmer "how to" document is available

aaknitt · Post by **aaknitt** » Sun Jan 15, 2006 2:36 pm

Hello all,

I've created a .pdf document detailing how to build an extremely cheap and simple programmer for Minitor III/IV (and probably V) pagers. The document also shows how to modify a charging stand to use as the programming cradle. Unfortunately my ISP doesn't give me any web hosting, so I don't have a way to post it on the web. If anyone here has web space and they'd like to post it I'd be willing to make it available. Or, if anyone wants the .pdf I can supply it directly via email.

Next project is to make another document showing how to fix the Mintor III pagers that stop alerting due to PC board flex.

Andy

ffexpCP · Post by **ffexpCP** » Sun Jan 15, 2006 2:54 pm

Is it the same as this: http://batlabs.com/pagerrib.html

Anyone have any luck building this? Any hints or tips?

aaknitt · Post by **aaknitt** » Sun Jan 15, 2006 3:14 pm

It's a simpler version of the programmers that are on the batlabs page. Absolute minimum parts count. It also shows how to modify a charging stand to use as a programming stand.

ffexpCP · Post by **ffexpCP** » Sun Jan 15, 2006 3:38 pm

That does look alot eaiser. Where did you get the ICs from?

aaknitt · Post by **aaknitt** » Sun Jan 15, 2006 3:54 pm

The ICs are available from pretty much any mail order electronics parts warehouse.

Mouser part numbers (http://www.mouser.com):
U1 - 595-MAX232N
U2 - 511-L78L05ABZ

Digikey part numbers (http://www.digikey.com):
U1 - 296-1402-5-ND (out of stock right now...more expensive ones are available)
U2 - 296-1365-2-ND

Jameco part numbers (http://www.jameco.com):
U1 - 24811
U2 - 51183

That should get you started. Also, you can replace the MAX232 with something like a MAX233, which doesn't require the external capacitors, but it's a more expensive chip.

Andy

aaknitt · Post by **aaknitt** » Sun Jan 15, 2006 6:16 pm

I posted a .pdf version of the document in the files section of the twowayradioprogramming Yahoo group (the more popular radio-programming group didn't have enough file space left). Anyone can download it from there, but you have to join the group first.

http://groups.yahoo.com/group/twowayrad ... ing/files/

If anyone would like a .doc version for conversion to HTML I'd be happy to provide it.

Andy

Iguana · Post by **Iguana** » Mon Jan 16, 2006 6:51 am

The original programmer is working good! tested on motorola advisor!!!
But you can use only MAX232, at most pagers you don't need the LM339 quad comparator!
Good Luck!

aaknitt · Post by **aaknitt** » Mon Jan 23, 2006 2:58 pm

I put the documentation up on googlepages so it's available to everyone.

http://radioetcetera.googlepages.com/minitorprogrammer

That should get you there.

Andy

pjpesanka · Post by **pjpesanka** » Fri Feb 17, 2006 2:55 pm

Has anybody else successfully tested this circuit? I tried using it with my Minitor IV but have had no success. Any tips?

aaknitt · Post by **aaknitt** » Fri Feb 17, 2006 5:08 pm

Can you tell me more about your setup? What are you using for the programming cradle? Did you make sure to put the pager in programming mode before trying to read it (that one has caused me some grief

)? Are you using a laptop or desktop (I've used it with both, but I'm still curious)? Have you done any kind of troubleshooting, and if so, what did you check?

Andy

pjpesanka · Post by **pjpesanka** » Sat Feb 18, 2006 4:25 am

I am using a the modified charger as the programming cradle, and I have put the pager in programming mode (C position hold reset button and turn on) DB9 serial connector. This is an older desktop computer, has successfully programmed other motorola radios, just can't seem to get this interface to work. I have good continuity from the charger pins into the circuit and from the DB9 plug into the circut and am getting +5v coming off the L78L05. The only thing I haven't checked is the connection from the charger pins into the pager, but I am not sure of a good way to check that.

aaknitt · Post by **aaknitt** » Sat Feb 18, 2006 7:59 am

Ok here are a couple things to check.

First, the polarity of the capacitors does matter! The curved line on the schematic is negative, the straight line is positive. C1 is the one that usually gets messed up, since the negative terminal of the capacitor goes to positive voltage. Counter intuitive, but that's the way it has to be.

Next, the MAX232 is a level converter that changes RS232 voltage levels to TTL voltage levels. RS232 uses +12V to represent a "0" and -12V to represent a "1". TTL levels are 0V for a "0" and +5V for a "1". So, to see if the circuit is working, measure the voltage on pin 2 of the DB9 when it is plugged into the computer. This would be the voltage between pin 2 and pin 5 (GND). If the voltage is -12V, the voltage on pin 13 of the MAX232 should also be -12V (since it's a direct connection to the DB9 pin 2), and the voltage on pin 12 should be +5V. If the voltage at pin 2 of the DB9 is +12V, the voltage on pin 12 of the MAX232 should be zero. That covers the path from the computer to the pager. To check from the pager to the computer check the voltage on pin 11 of the MAX232 with the pager connected and in programming mode. If the voltage is zero, then pin 14 on the MAX232 should be at +12V (it will probably be more like +8V, but that's good enough). If the voltage on pin 11 of the MAX232 is at 2.5V or higher, then the voltage on pin 14 of the MAX232 should be -8 to -12V.

Here is a link to the datasheet of the MAX232, if you don't have one already http://pdfserv.maxim-ic.com/en/ds/MAX220-MAX249.pdf

Also, if you have an oscilloscope it makes troubleshooting much easier...you can trace the serial data through the circuit to see where it's not getting through.

I'm not sure if there is a way to check continuity with the pager contacts per se, but if I remember correctly the pager puts some voltage onto the TX pin when in programming mode. You could check to make sure you're seeing that voltage in the charger base. I could be wrong though. My voltmeter is out in my truck right now, but maybe later today I'll check and report back.

Finally, one of the more common mistakes when building circuits like these are getting the TX and RX accidentally swapped somewhere in the circuit.

Hope that helps!

Andy

pjpesanka · Post by **pjpesanka** » Mon Feb 20, 2006 4:39 am

I had the polarity on C2 reversed and the RX and TX swapped going from the DB9 into the MAX232. I was reading on http://www.lammertbies.nl/comm/cable/RS-232.htm that pin 2 was the RX and pin 3 was the TX, where they were reversed on the schematic for the programmer. Swapped those around and now I can pull a codeplug from my Minitor IV. The RSS is complaining about a resource error now though so I will have to troubleshoot more.

Thanks for your help

PJ

aaknitt · Post by **aaknitt** » Mon Feb 20, 2006 10:00 am

aaknitt wrote:Finally, one of the more common mistakes when building circuits like these are getting the TX and RX accidentally swapped somewhere in the circuit.

I guess that should have been "somewhere in the schematic"

Sorry about that! I'll get it fixed later today sometime.

Andy

aaknitt · Post by **aaknitt** » Mon Feb 20, 2006 5:16 pm

The schematic posted on the web has been fixed. Please let me know if you find any other errors.

Thanks!

Andy

Post by **MoReloader** » Sun Jan 16, 2011 7:09 pm

I have followed these directions for a programmer for III/4 and it works great. Then set up pins for the 5 and can not get the 5 to read the codeplug. No error just failed to read codeplug. Is there an issue of reading the codeplug with too new of version of the software. I used 1.7.2 I believe, and this pager is at least a couple years old. I have tried pushing the wires against the pager and it still does not read. I think it is software related.

Thanks

Programmer "how to" document is available

Programmer "how to" document is available

its working good

Re: Programmer "how to" document is available