Search

Paul Bleisch

Author

Paul Bleisch

Make a Custom Membrane Keypad for Arduino

My son got one of these Leap Frog toys a few years ago as a gift.  He enjoys playing with it very much.  I am not sure how much counting and learning he is doing but it makes funny noises and sings to him so its a lot of fun.

Recently the unthinkable happened.  It died.  Not the batteries but something else.  I took the back off to look at what might be wrong (which was very easy for a toy).  Unfortunately, other than the speaker, a switch, battery compartment, and a ribbon cable to the front, there wasn’t much to investigate.  A couple of glop tops and nothing else.  I fiddled a bit more with it but everything “external” seemed fine.

Did I mention my son really loves this toy?

Continue reading “Make a Custom Membrane Keypad for Arduino”

Advertisements

“Lab” Upgrades

For the longest time my home electronics projects have been done on a 60″ x 30″ folding table in one of our spare bedrooms.  My growing collection of project boxes, spare parts, and equipment finally started to put stress on my furniture – particularly my table.

The old lab table.
The old bowing table in its “clean” state.

I spent embarrassingly too long fretting over whether to buy a desk or build it.  If I bought something, what should I get?  Do I need an “electronics” workbench?  If I build it, what should I build it out of?  I probably spent five months going back and forth – all the while piling more junk on my table.

Continue reading ““Lab” Upgrades”

Ancient History: Let’s Build Our Own Console!

Found a link to one of the many “big huge awesome” projects that we started in ACM@UIUC back in the day. I’m pretty sure this page is the only thing that actually came out of this project. 🙂 I think (hope?) that I’ve gotten a little better at completing things (retro pc project and this blog not withstanding).

These big huge unfinished projects were not really failures. Many of the people who worked on projects like these at ACM@UIUC are now veterans of the startup scene or leaders behind the scenes at the hot tech shops around. I look back at these projects as ambitious and a great learning experience.

Update 1/25/2017: updated link to be via archive.org.

A Simple Remote-Controlled Arduino Tank

A little while ago my son was showing some interest in robotics. His birthday was coming up and we were having trouble deciding between a beginner robot kit focused more on construction or lots of bits and pieces.

The kit we looked at was the Elenco OWI ATR – All Terrain Robot:

The alternative was to build a robot based around Arduino. There are many robotics kits out there but I liked the idea of investing in Arduino as the basis for exploring robotics. I figured we would get the Arduino Uno, a few shields to control motors and sensors and whatnot, throw some wheels on it, and blammo, have a robot.

Continue reading “A Simple Remote-Controlled Arduino Tank”

From Breadboard to Protoboard

The time has come to clear some space on my breadboard so I can continue to build out the remainder of the system. I’ve collected a few prototype boards from Futurlec by tossing a few in each order over a few months. I bought a few different flavors of boards (PROTO777, PRBRDLG, and EXPBRD) to see which worked best for my random projects.

Continue reading “From Breadboard to Protoboard”

Debugging stuck bits

I’ve been blocked on making progress on the retro pc project due to bad reads from the ROM. The seemingly simple snippet of boot code should light an led wired to to the i/o ports (any port).

section .text
resb 0x7F0
org 0x7F0

start:
mov al, 0x1

 

again:
out 0x10, al
jmp again

When assembled, this turns into the following x86 bits:

00007f0: b0 01 e6 10 eb fc

Unfortunately, when I tried to boot the bundle of wires on the breadboard, I got the following while looking at AD[0:7] on the 8088.

00007f0: b0 01 e2 10 ...

Continue reading “Debugging stuck bits”

Using Ultrascope for Rigol DS1052E

I’ve become more and more annoyed at having to export images from my Rigol scope to a flash drive plugged into the device. I’d much prefer to capture signals and images directly from my Macbook. Unfortunately, the PC software that comes with the Rigol — Ultrascope — does not run on Mac OS X. Boo. Over the last couple nights, I’ve played with the idea of writing a Cocoa app to pull data from the scope. USBTMC + Cocoa seems like a pretty good path to go.

Continue reading “Using Ultrascope for Rigol DS1052E”

Sometimes it is a bad part… sometimes.

I’ve spent the last few weeks working on my retro pc project. The first step with the 8284 seemed to go well but the trouble began when I tried wiring up the 8088. I wasn’t getting anything remotely close to the expected boot sequence. According to the datasheet and
The 8088 Project Book
a few clocks after dropping RESET back to zero, the 8088 should raise ALE after placing 0xFFFF0 on the address lines.

No such luck.

Continue reading “Sometimes it is a bad part… sometimes.”

Starting a Retro PC using The 8088 Project Book

Several months ago, I purchased a copy of Robert Grossblatt’s classic The 8088 Project Book in hopes of building a retro 8088 computer. My plan was to scavenge the parts from craigslist, ebay, and a couple Seattle area used computer junk stores. My adventures locally didn’t result in many parts though I did have much fun finding all those old ISA cards. I did manage to buy quite a few intel parts (8259s, 8255s, etc…) and a bunch of 74xx TTL parts from a gentleman in the area who was clearing out old stuff. But I still didn’t have an 8088 and a couple other necessary support parts. My queries to craigslist resulted in offers to sell me old 8088 PCs for crazy prices. Eventually, I gave up on finding the parts locally and started adding the remaining pieces to various digikey and futurlec purchases. This past weekend the final piece – the 8284 – arrived which is good because it is pretty important being that it drives the clock for the entire system.

Continue reading “Starting a Retro PC using The 8088 Project Book”

Powered by WordPress.com.

Up ↑