Wednesday, 27. February 2008
7x5 found a bad LED
rsbohn
11:53h
I added the last three LEDs to my 7x5 display awhile back, but didn't actually test them until this morning. One of them wasn't lighting up. Took a close look and I can see what a poor solder job I did. The flying wire wasn't even touching the next on in the row. Have to fix that next time I get the iron out. I want to try out the bidirection LED thing using this board. I want to read all seven LEDs in the rightmost column and see which one you are touching. For starters I'll just light up the whole row, so you can see a moving bar of lights when you run it. Eventually you could use this to set a value: the center line is no change, each row higher means increase faster, each row lower means decrease faster. Or, from top to bottom: +++ ++ + 0 - -- ---. To get started I created a new project in Atmel Studio for the Tiny2313 chip. This time around I'm not using the overflow interrupt for timer0, I'm just polling the overflow flag and resetting it. It didn't take long to get a row-strobe test pattern running. I've added sockets for ISP to the board, so I can just build the software and then upload it without disconnecting anything or removing the chip from the board. Sure makes things easier. I should save off a copy of the current firmware, it's nice to have a test pattern to make sure all the LEDs are lighting up. That's how I found the bad solder joint this morning. Find this story interesting? Check out uC Hobby!
|
8140 days of detection
mod: 12/3/08, 5:42 AM days of detection... PMOG owner
BiographyRandall Bohn lives in Orem, Utah, USA. He works as a Software Quality Engineer. He is a big fan of the AVR line of microcontrollers. He has been in the computer industry since 1989. Randall is married and has three children. rsbohn can be reached via gmail.com. status
Youre not logged in ... Login
Amazon.com DVD Shop
Amazon.com DVD Shopmenu
search
related
calendar
recent updates
Arduino Starter Kit
MAKE Blog How-to Tuesday posted a challenge: Optimize the sketch code for a pressure sensor bar graph. Here is my second attempt: int gate[] = {10, 20, 50, 100, 200, 32767}; void setup() {DDRB = 0b00111110;} void loop() { int dval = 0; int rval = analogRead(2); for (int x = 0; rval... 12/3/08, 5:42 AM Measuring Supply Voltage
I'm running my latest handheld computer on solar power. It starts up when the sun rises and runs all day. I started wondering how I could measure the voltage coming in from the solar panel. I came up with a way to use a diode and a resistor and the... 7/29/08, 9:53 AM Ten Pin ISP adapter
I've already built a six pin ISP adapter, but my Olmex cards use the ten pin ISP. I put a header on a scrap of perf board, added an LED for the heartbeat, and then connected the ten pin cable. Actually it is a fifteen pin cable, off a joystick... 7/16/08, 10:00 PM Hello 5x7 Style
Wrote a new firmware for the 5x7 display. Now it scrolls out 'hello' over and over again. I'm running it on a solar panel, so it wakes up with the sun and runs all day long. When I built the LED matrix I put resistors on the five columns. I'm starting... 6/17/08, 12:48 PM Provo, Utah
With a walkable downtown and access to two Universities, Provo Utah is a great location. I live next door in Orem. Kipplinger: Provo: Pristine Tech Mecca (Video) (Text) 6/2/08, 10:07 AM Another release of AVRISP sketch
There is a new release of the AVRISP emulation sketch for Arduino: avrisp.02.zip. This one should work with Mega8 and Mega168. mega-isp 5/28/08, 4:48 PM Sorting Out Page Sizes
There is a new release of AVRISP Emulation for Arduino. This is an Arduino firmware that allows you to program other AVR microcontrollers. The new zip file (avrisp.01.zip) should compile on the current Arduino IDE, and I changed the comments that put the wrong labels on the SPI pins. Go ahead... 5/27/08, 11:31 AM Flash Problems
I'm building a project using the AVR ATMega8 microcontroller. Once I got the thing wired up to where I could write firmware to it I found that it was always failing. I made a .hex file full of 0x10 values (256 bytes worth) and tried uploading that to the chip.... 5/16/08, 2:56 PM William's Arduino Board
I'm building an Arduino-compatible board for William. I'm building it on the Evil Mad Scientist MegaXX8 business card. It will have four built-in LEDs and a USB interface. It will also have connectors so he can use it with a breadboard. Perhaps we can connect it to some of his... 5/15/08, 7:26 AM Cybord Signal Detector
Some digital radio signals use Frequency Shift Keying (FSK). This often has one frequency for a Mark and one for a Space. I plan to build a cybord or other chip that will decode an FSK signal, producing three different values: NO_SIGNAL, MARK, and SPACE. The signals would then go... 5/15/08, 7:20 AM |