Hotsolder » microcontroller

SuperProbe

wd5gnr — Sat, 29 May 2010 13:24:21 +0000

We have a group of hams that homebrew that meets once a month for breakfast. A while back I noticed the SuperProbe and thought it would be a good way to get some of the guys started with Microchip PICs.

I started out breadboarding the circuit, but they will eventually go into nice cases we bought from Kelvin.

Here it is in logic probe mode, reading a logic 1 (High):

And here it is reading a voltage (just an output from a pot):

I want to make a few modifications — at least a buzzer (shared on the switch lines) and maybe something with the serial port, but I wanted to “base line” it first.

Stay tuned.

Update. Here’s a video of the above in action:

And I have in fact built this in a nice case (finally). Here’s some pictures:

Probe (outside view with red bezel removed)

Inside view of the probe

Where have all the posts gone

wd5gnr — Tue, 16 Feb 2010 14:15:05 +0000

It looks like I’ve gotten busy lately and neglected Hotsolder. Not exactly. You know a lot of my postings relate to embedded systems. You might also know that I have a long history with Dr. Dobb’s Journal as an author, columnist, and editor. Well, I’ve recently started blogging about embedded systems on the Dr. Dobb’s web site. Stay tuned to Hotsolder for things that don’t fit there, but for embedded items, check out DDJ.

SXKey Under Wine

wd5gnr — Thu, 14 Aug 2008 05:07:56 +0000

Since I often program Parallax/Ubicom/Scenix SX chips, I needed a good way to program the chips under Kubuntu/Ubuntu. The installation of the software under Wine worked fine. However, the program didn’t work right away.

Of course, I had already set up ~/.wine/dosdevices to have a link for com1 (ln -s /dev/ttyS0 ~/.wine/dosdevices/com1). You need to make sure you have permissions on that device also. Rather than open the port to the world, I noted the port is in the “dialout” group, so you can simply add yourself to that group to get read/write access to the port. For example:

alw@enterprise:~$ ls -l /dev/ttyS0
crw-rw—- 1 root dialout 4, 64 2008-08-13 06:45 /dev/ttyS0
alw@enterprise:~$ sudo usermod -a -G dialout alw

Naturally if you aren’t using your real COM1, you’d need to change /dev/ttyS0 to the right designator (although you can still call it COM1 for Wine!).

The com port autodetection was the culprit. The trick was to open ~/.wine/user.reg and add this line:

[Software\\ParallaxInc\\SX-Key\\2.0\\Configuration\\ComPort]
“Configuration\\ComPort”=”COM1″

I’m not sure if it mattered, but since the entries are alphabetical, I put it in the “right” place. After that, it all worked fine!

Clubland dvdrip

Uncommon Nonvolatile Memory Powers 8051

wd5gnr — Thu, 12 Jan 2006 00:24:00 +0000

The 8051 is a popular microcontroller core. In the “old” days we used external EPROMs. Modern versions have onboard EPROM or EEPROM (like flash).

Ramtron recently announced their new 8051 with onboard FRAM (8K worht). FRAM is a nonvolatile memory that is fast to write, byte-writeable, and has virtually unlimited read/write cycles. So you get the advantages of nonvolatile memory without the disadvantages of flash.

FRAM is a ferroelectric-based technology that does not require battery backup like SRAM. Of course, you can get FRAM to include with a traditional microprocessor, but this is the first microcontroller I know of that has FRAM right in the device.

Link: http://www.ramtron.com/VRS3xxx/default.asp