Anyone of you has an experience with 8x32 matrix LED programming in AT89S52 with 74HC154 ? I'm using keil and C, I've done vertical scanning and want to know on how to send the pattern into those matrixes.
I will include the schematic if needed
Port 1 is the column
Port 2 is the row,
Any help w...
@Kellenjb Well I actually noticed this on my computer first. I have a laptop and it has antennas behind the screen and a microphone on a PCB near the top of the screen. My friends started to complain few weeks ago of distortions and I initially thought it was a problem with the PCB (which has seen better days but is still working).
@Kellenjb Today I was experimenting something with a electret microphone connected to a computer sound card and I noticed that the external microphone produces signal when the WiFi is working and the microphone is near the antennas. I also tested this near my router's antennas and it's producing noise there too.
@Kortuk I don't think that the power supply is picking up the problems. This is inside of a laptop (checking with a separate circuit is next on my list) and the microphone is connected to the sound card by at least 40 cm of shielded cable (the shield seems to be unbroken). It could be that the shield is picking up the noise. I also tested this with an external microphone and it shows same results.
@Kortuk And I also tested the external microphone several meters away from the computer with a 2.4 GHz RC airplane radio and it picked up interference from that too.
@Kortuk I just tried with a circuit external top the computer and it too picks up some noise, but it's much much weaker than what I'm getting. I'll probably end up researching this and asking one of those "one-off" hack questions once I do some basic research.
I think I got it. It seems that the microphone capsule itself may be picking up interference. When I connected the body of the capsule to the ground on the external microphone, it stopped picking up noise. When I disconnected ground from the body of the capsule, it started picking up noise again.
@Kortuk In the end I may even do that. The external microphone I'm using is [Hitpoint PMOF-9767NW-46UQ ](www.pselectronic.cz/pdf/5115/5115002.pdf) and it seems t be just another generic electret. I'll see if I can identify two other microphones on which I've noticed this.
@chrisstratton, Please also feel free to come discuss moderation topics in here. I had quite the learning period as I was starting to moderate spending itme in the moderator chatroom just learning from other mods of other sites like stack overflow and such.