|WP 34S flash adaptors now available|
Message #1 Posted by Harald on 27 May 2012, 11:07 a.m.
Today I have assembled and tested the "final" (at least for) version of my flash adapter, and it worked as expected.
It allows you to directly connect your WP 34S to your computers USB port, so there is no need for the HP flash cable and USB to serial converter anymore.
In addition to this, the calculator runs on USB power while it is plugged in. This helps conserve battery, as you can just plug it in when you are running long programs. When you unplug the USB connector, it automaticly switches to battery.
There is also a resistor for the IR LED (for printing) on the board. The LED can be soldered directly to two pads on the board. The LED is not pre-installed, because the leads need to be cut and bend according to the position of the hole for the diode.
This is what the PCB looks like:
And this is how you install it:
First you need to cut away the plastic suports arround the top left screw post:
Then you can glue the PCB in place:
This is where the wire for the IR-Printing needs to be soldered:
You will also have to remove LB1 and LB2, connect battery, Vcc, GND, RxD and TxD and (if you haven't already done that) install the crystral and capacitors:
Detailed instructions of what to connect where will follow. This is just to give you an idea of the work involved in installing this.
Finaly you will have to drill a 3mm hole for the LED and cut a hole for the micro USB connector. This is a bit tricky if you want to be exact. I got the best results when drilling out the corners of the hole with a small (1.5 to 2mm drill) and then cutting the rest with a sharp knife. The result looks like this:
There is also a version that includes Lithium-Ion battery handling:
However it is even more work work to install this, as you have to make room for the battery. This does not include the resistor and the pads for the IR diode, so you will have to install those seperately.
And there is a very basic version for those who want neither printing nor switching to USB power.
Finaly I have also made a PCB to convert the HP flash cable from serial to USB. So no need for the USB to serial adapter anymore. This comes without the switches, which you will have to desolder from the original PCB and install in this one. You will also have to solder the two cables to the PCB:
And now (I hope this is OK on here, please remove if not) the prices. All prices include shipping within Germany, the rest of Europe will be 50 cents extra, the rest of the world +1 Euro:
Basic Flash Adaptor (without IR and USB power): 12.50 Euros
Flash Adaptor with USB-power and IR printing (including IR diode): 13.50 Euros
Flash adaptor with Li-Ion handling: 15.00 Euros
HP cable conversion kit: 13.00 Euros
And a few extras you might or might not need:
Crystal and Caps: 0.25 Euros
60mAh Li-Ion battery: 4.60 Euros
micro USB cable: 2.00 Euros
Edit: I have had a few questions about payment via PayPal. As I am not making a hughe profit on these, I am not too keen on Paypal, as I don't like them makeing more profit on these than I do. So I prefere bank transfer if possible. I appreciate this is not possible for everyone, especially for people from outside Europe. You can still pay via PayPal, but unfortunately I will have to add another Euro to the price to cover the fees. Sorry about that.
Look at the pictures for my email address. It is printed on the PCBs
PS: Initially I used a mini USB connector. In case you prefere that, I still have some Li-Ion boards left with that. They are the same price as the micro USB ones.
Edited: 28 May 2012, 8:12 a.m. after one or more responses were posted