Flash with 2.5mm Headphone Jack

[rprosperi]

(01-30-2015 11:11 PM)BarryMead Wrote:  A while back Marcus Von Cube posted a thread on how to flash a WP-34S with a 2.5mm headphone jack. This posting is similar to his with a few simplifications. I decided to mount the 2.5mm headphone jack in the center of the calculator along the top edge. With this mounting arrangement it is easier to cut away the plastic of the case to make room for the jack, and you don't need to cut away any of the mounting struts. Since I already owned one of the FTDI TTL-232R-3V3-AJ cables from another project my cost to build was less than with Harald Pott's USB board. See the attached photos. There is one advantage to this connector over the USB connector. If you have two or more calculators built in this way, you can use a 2.5mm crossover cable to transfer programs and data directly from one calculator to the other without a computer.

The connections are:

1. Tip (USB Cable TX) goes to JP5 (Calculator RX)
2. Ring (USB Cable RX) goes to JP6 (Calculator TX)
3. Sleve (USB Cable Gnd) goes to Battery Minus (Calculator Gnd)


The attached spreadsheet shows where to order everything to make your own WP-34S with the 2.5mm headphone jack. If you order everything it costs more than with Harald's USB board, but I already owned the cable so it cost less in my case.

Cool idea Barry, will make it simpler for lots of folks. I guess I missed Marcus' earlier suggestion.

FYI - when I click the thumbnails, new pages open with photos, but those photos are the same size as the thumbnails (prob just pointing to wrong set of pics)