PM9549 RS-232 Interface for Philips PM6304 RLC Meter - Page 1
Forum section: electronics / projects

author: Geek459
author_rank: Contributor
timestamp: February 05, 2021, 01:36:03 pm
content: Hi guys ,i've seen a pm-6304 RLC meter without communication interface , from service manual i've seen the rs-232 interface is composed of several discrete components and a 80c652 CPU romless , so i decided to try to realize the interface by myself.The only missing is the rom code , someone has the copy or can do the copy of the bin file for me?If i will realize the interface i will post the project.Best regard.. Claudio

author: Geek459
author_rank: Contributor
timestamp: February 10, 2021, 03:07:50 pm
content: Hi , i am here , i've done a layout of the interface , but seem to be very difficult finding rom bin file.Anyone has it?

author: coromonadalix
author_rank: Super Contributor
timestamp: February 10, 2021, 06:30:18 pm
content: good work, hope you'll get your answer

author: Geek459
author_rank: Contributor
timestamp: February 12, 2021, 02:10:02 am
content: Hi , revised layout , when i opened instrument and cecked with a paper model 1:1,dimensions are too much.I search firmware but still missing ,the interface is the same for pm6304 and pm6306 and i have not found a even a seller for it.But i don't quit.

author: coromonadalix
author_rank: Super Contributor
timestamp: February 12, 2021, 04:18:42 am
content: you wont find them anymore unless you get very luckyI did a design for the dc bias board for the 6304 and 6306, never heard if someone built it

author: Geek459
author_rank: Contributor
timestamp: February 13, 2021, 12:44:06 am
content: While i'm searching rom firmware ,i decided to investigate on commands data flow between CPU board , display ,keyboard , IR receiver (RC5 encoding) , Analog Board.At the moment i've found in IC2Bus 7 timed access , 1 to 5 are blank(no data , only clock and data end bit),6 do write operation at address 0xAE (may be Analog Board) 7 do write operationsat address 0x70 ( to display).Keyboard is readed by a SAA3007 (infrared remote transmitter) and output go thru a 74HC132 (NAND) to a CPU pin P1.0 ,while ir receiver TDA3047P go to CPU P1.1 .Conclusion : P1.0 and P1.1 are gpIO and in my mind i think philips used a ir encoding for keyboard to be able to read keyboard and remote in the same way , so i think the remote IR has the same infrared remote transmitter.I have some waveforms of this but need to organize it , for the moment i will do a small remote with a pic 12f1840 to veryfy if what i think is true.Soon i will post some waveforms.Someone has a remote ir to read transmitted codes?Best regard.. Claudio

author: justin010306
author_rank: Newbie
timestamp: April 16, 2021, 10:20:06 am
content: Interested in your IR.My 6306 has a serial port board, I will try to copy the firmware.

author: Geek459
author_rank: Contributor
timestamp: April 21, 2021, 11:17:52 pm
content: Hi justin, lastly I was quite busy and i momentarily stopped the project , anyway since my last post I've made progress , i've decoded all display segments and keyboard commands interposing between one wire keyboard data and cpu a MCU(pic18f4550 i used this beacouse i had it) so all keys are processed by a MCU and repeated to the PM6304 cpu, this let me send keyboard commands also by the rs232 of the pic18f4550 so i can send commands from pc ad read data from display to pc using a little software written in c, this is not full remote control like a gpib or rs232 but is usable. Regarding IR remote i've tried several codes with RC5 encoding but i get error and for the moment i don't see the right way , but not at i've some time i try it again.If you can make a copy of the eprom i'm very grateful , i post some images of the project.best regard .. Claudio

author: Geek459
author_rank: Contributor
timestamp: April 21, 2021, 11:33:38 pm
content: I apologize image IMG_2381 is not reletive to interface but is a power switch that i've mounted to install a front panel button to switch on/off the instrument , it's frustrating to use the rear switch especially for me as the back of the instrument is a bit difficult to reach , for the momenti i've mounted internally the switch , now I'm studying how to make a rod that reaches the front by sliding it inside a side groove of the instrument container.