Friday, September 13, 2019

Assembling a TinyMod4

TinyMod has been updated again, but only slightly. It looks nearly the same. It behaves exactly the same. The changes are to make assembly easier and more robust. The diodes have been replaced with an MCP23017 i2c port expander. The microcontroller has been moved out from under the key switches, for easier assembly and repair. The switch footprints now only allow MX style switches and the switches fit better, requiring less solder. The firmware has been rewritten to accommodate the port expander. If I hadn't told you I'm not so sure you'd notice the difference.

The first step is to solder in the i2c resistors and the headers for the microcontroller.

Then we solder in the slider switch and the port expander from the back side. A rubber band holds the MCP23017 in place as we tack it at the corners.

The firmware is flashed into the microcontroller, which is then soldered into the headers on the bottom side.

Now it's good to set the protocol switch to NKRO, plug in the microcontroller and short each of the key switches to see if the right characters come out on the screen.

Once we know things are working so far, we start inserting the key switches, then solder them in. You can see the port expander here too. It's sitting between two rows of switches.

The bottom plate of the keyboard is just another bare PCB with spacers. That's a nut driver for 4-40 machine screws in the upper right corner. I 3D printed it.

Join the two halves like this, then bolt them together with the 4-40 nuts.

The final product looks like this after inserting the keycaps. I feel as though this is pretty close to being a final version. We'll see about that.

Tuesday, July 2, 2019

How to Buy a TinyMod

It's been pointed out to me that I didn't say anywhere on the main page just how to go about ordering a TinyMod. This post is a temporary solution. I'll try for a more long term one later.

To order a TinyMod, send me an email at  saying what you would like (a TinyMod) and giving me your shipping address. I need this to figure the shipping cost, but also I don't necessarily want to rely on the address that PayPal gives me. I'd rather hear it from you.

Once I get the email, I'll send you back a PayPal invoice. The invoice will be for $160 plus shipping, which is $7.90 in the US and around $24 elsewhere. Those are US dollars. You can pay the invoice with your PayPal account if you have one, or by credit card. PayPal will process credit cards.

Shipping is with the US Postal Service, Priority Package. In the US it should arrive in two or three days. Out of the US it's more like 5-10 days.

This somewhat unconventional way of doing things allows me to keep from having to accept credit cards myself as well as from having to set up a website. It's working well for me for now.

Monday, April 22, 2019

New Version, TinyMod3

Another change to the TinyMod. I've moved the thumb keys 5.5mm further from the row of keys above. I think it's more comfortable this way.

Since I was laying out a new board anyway, I also redid the wiring. Now every key is wired separately, including the S- keys and the asterisk keys. I'm still using TX Bolt as the serial protocol, so you can't tell there. But using the NKRO keyboard protocol you could make use of them in Plover. Of course, hacking your own firmware you can do whatever you like!

The boards are just a little bit longer and wider, but not much. The microcontroller has moved from the right side to the left, but is still covered by the top PCB. The slider switch for choosing the protocol is also now on the left side.

It's different firmware because of the change in wiring, but the functions are the same. You shouldn't notice any difference there.

The price is the same, $160USD for the keyboard, $7.90 shipping in the US, about $24 for most of the rest of the world. Sales tax $11.60 if you're in California like I am.

Hope you like it!