need help with pin outs for ADM3202 chip please

[Bruce Larrabee]

I am building a RS-232 cable because I don't NEED USB and don't currently have a FTDI board. I DO have a serial port (my machine is not that old just fully featured). Is there any reason that I MUST build a USB cable?

You guys in no way answered my question. I have been all over this site and sourceforge and the manuals. This info is not in any of the places I've looked and that includes your suggestions.

I know the port pin outs. That is why I didn't ask for them. Referring me to a page showing them doesn't help.

Now could someone PLEASE answer my question:

I'm building a programming cable for the w34s. Can anyone tell me which signals to connect to the ADM3202 chips pins 11,12,13 and 14.

Thanks again.

[StephenR0]

I can't answer your question about pins 11, 12, 13, and 14 on the ADM3202 chip. I've just programmed it with the programming pins on the back of the calculator. The reason people are suggesting using a USB to serial cable is that the programming voltage and the voltage of these cables is 3.3 volts, not the +12 and -12 volts of a serial port. You either need a maxim level converter chip to let you use a serial port or you can use one of the cheap USB to serial adapters that exist. As far as the programming port is concerned, you only need to use three pads, TX, RX, and ground. The other pads are for clearing the previous programming before loading the new program. But that can be done with one paper clip to short two pads and another to push the reset button in the hole in the back of the calculator. Does this make more sense now?

[Paul Berger (Canada)]

(01-26-2014 12:09 AM)Bruce Larrabee Wrote:  I am building a RS-232 cable because I don't NEED USB and don't currently have a FTDI board. I DO have a serial port (my machine is not that old just fully featured). Is there any reason that I MUST build a USB cable?

You guys in no way answered my question. I have been all over this site and sourceforge and the manuals. This info is not in any of the places I've looked and that includes your suggestions.

I know the port pin outs. That is why I didn't ask for them. Referring me to a page showing them doesn't help.

Now could someone PLEASE answer my question:

I'm building a programming cable for the w34s. Can anyone tell me which signals to connect to the ADM3202 chips pins 11,12,13 and 14.

Thanks again.

You can get a data sheet for the ADM3202 at http://www.analog.com/en/interface-isola...oduct.html click on Acrobat logo beside the words "Data Sheet" the data sheet includes a pinout of the chip.

As per pinout in the datasheet the Adm3202 is a 18 pin DIP or SSOP package that provides two channels in either direction however you only need one in each direction. The TxIN pins (11 & 10) expect a TTL/CMOS signal and convert it to a RS-232 signal on the corresponding TxOUT pin (14 & 7). The RxIN pins (13 & 8) expects a RS-232 level signal and convert it to TTL/CMOS on the corresponding RxOUT pins (12 & 9). So we only need one channel in each direction so and example would be on the calculator side connect pin 2 Tx0 would go to 11 (10) and pin 1 Rx0 to 12 (9) so now on the chip we would have RS-232 level Tx on pin 14 (7) and Rx on pin 13 (8) ( Pin numbers in brackets are the alternate channel on the chip) The RS-232 level Tx would be connected to Rx on your computers RS-232 port and the Rx connected to the computers Tx pin.

One other thing does your "FTDI board" put out RS-232 level signals? I have one here with a FT232RL chip on it and that chip outputs CMOS/TTL level signals at programmable levels one option is 3.3V suitable for direct connection to the WP34S. To provide RS-232 level signals this chip would have to feed a level convertor such as the ADM3202 or a MAX232.

[Marcus von Cube]

(01-26-2014 12:09 AM)Bruce Larrabee Wrote:  I'm building a programming cable for the w34s. Can anyone tell me which signals to connect to the ADM3202 chips pins 11,12,13 and 14.

I think your pinout question has been answered by Paul. The reason why I discourage the use of RS232 level converters (as used by the original cable) is power consumption. HP did a less then famous job on this by connecting the power input of the cable (to feed the converter) directly to VBat. This is convenient because no external power is requested but it's fatal for the batteries of the poor calculator if you just leave it plugged in for some time because it draws power from the batteries even if the calculator is turned off.

USB simply avoids all the hassle and the FTDI chips have proved to be reliable in combination with the programming boot loader.