Monday, September 21, 2015

Fixing Flaky LCD Monitor with ESR Meter

My Dell E2210H LCD monitor was really wonky.

Powering up from sleep, it would only occasionally come back to life, usually after resetting itself several times.

More often, it would power off or go into power saving mode, leaving the front panel buttons inoperative.

Occasionally it would reset or power off while operating normally.

Here's how I fixed it, using my DIY ESR test harness to find a bad capacitor without desoldering.

Thursday, August 6, 2015

Automated OLED Test Jig: eeZee MicroSD

How does one test boards one sells on Tindie?

With a fancy-pants, standalone, OLED-equipped, high-zoot test jig, of course.

At least, that's what I built for testing my eeZee MicroSD boards. They're microSD breakouts for breadboard Arduinos. They've got the microSD socket plus 3.3V regulator, level-shifter IC, and various passives.

The test jig features an Arduino on the top of a two-layer permanent breadboard apparatus. Power is supplied by convenient USB connector. I manually place the board onto good ol' pogo pins soldered into the D10-D13 positions (plus power and ground).

A red and a green LED indicates overall status, while the Digole Serial OLED displays pass/fail status for each of the tests: initializing the card, creating a file, and removing a file, with an overall board status.

The test takes just a few hundred milliseconds to complete. The test jig is ready to go at any time. Just plug in a USB cable for power I can run through dozens of boards in a few minutes.

Here's the source code for the test jig: TestJig.ino

Tuesday, March 24, 2015

Redlink Connection Refused

Trying to launch LPCXpresso Redlink server, getting a "connection refused" because a shared library is missing? Online forum threads like this one don't help?

Here's the real answer: actually troubleshoot and solve the problem on your unsupported Linux distro. It's easy, just read on...