This is a pair of modules that Maplin was selling some time back, to send stereo audio over a 2.4GHz radio link. The transmitter identifies as a USB sound card, I’ve personally used these units to transmit audio about 60ft. The transmitter, above, has a single button for pairing with
I was recently given this unit, along with another Behringer sound processor to repair, as the units were both displaying booting problems. This first one is a rather swish Mastering Processor, which has many features I’ll leave to Behringer to explain 😉 All the inputs are on the back of
As with the previous Sony Watchman hack, injecting a composite video signal into this one is just as easy. I desoldered both the VIF/SIF IC & the digital tuner control (the tuner controller was still injecting it’s indicator into the video circuitry with the IF IC disconnected). Composite video is
This is an Audio DSP chip from the early 90’s, used for sound effects in audio mixing consoles. Unfortunately I couldn’t find much info on these. The die is massive, 10mm square at least. Interestingly, the markings on the die indicate it’s a TMS67002, maybe there was a different internal
Continue readingIC Decap: Texas Instruments TMS57002 Audio DSP
It’s been a while since I’ve done a proper radio based post, so it’s a bit of a shame that I have to start off with a rant, but it’s required in this case. One of the local 70cm repeaters, GB3WP seems to have many problems. The largest one seems
So, here is where all the action happens. Main radio of course is housed on the left, it’s partially hidden under my currently over-populated breadboard. All 3 monitors are linked to the same PC, using a pair of video cards. This is a very flexible system with so much screen
I’ve had a couple of viewfinder CRT modules for a while, & haven’t done much with them, so I decided to make a very small B&W monitor. I ordered a small transparent ABS box when I made a large order with Farnell, that turned out to be just about the
Now this is amusing, captured tonight on GB3MR, the usual unlicenced plonker is now threatening us all on the air with the Police – not sure where he’s getting a criminal offence out of the fact that everyone on the repeaters is moving around to avoid him, but still. Nor
I caught even more abuse on the local repeater this afternoon, this went on for a long time, into the early hours of the morning, having a conversation with himself as per usual. By the sounds of it alcohol was involved, the speech got more slurred as time went on.
I often find myself carrying by go bag up to the boat during trips, so I can do some radio. However at 16lbs it’s a pain on public transport. A fixed radio was required! Another Wouxun GK-UV950P was ordered, and the fact that the head unit is detachable from this
Here we go again with the GB3MR local idiot. He does always try to get a response from people, but we seem to be able to filter out this crap. 🙂 Here’s the audio for your listening pleasure. 🙂 00
I think the headline speaks for itself… The usual group, with their Baofengs… Grossly over on the power! After this, they then went up to 446.070MHz, which is in the guard band between channels. All the while admitting they’re using massive high gain antennas as well. Shortly after, they
Continue readingMore PMR Abuse – Tonight’s Menu: Casual Racism
Here’s some audio from last night on PMR, the regular group seem to be getting a little hacked off 🙂 (I do love the way these guys go on about abuse on the band when they’re transmitting on enough power to rival the BBC, they mustn’t know that PMR446
Since my new Wouxun has audio output jacks, I figured it would be useful to have the ability to record what my rig hears, if anything interesting comes on the air. Under Linux, I use an application called, (creatively enough), Audio Recorder. Using a simple connection to the mic input
I’ve been doing some tinkering with the RN-52 Bluetooth Audio module from Roving Networks, in prep for building a portable wireless speaker system, & thought I’d share my designs. Initially I was having some issues with RF noise on the audio output from the RN-52, as I was only using
As the first USB hub I was using was certainly not stable – it would not enumerate between boots & to get it working again would require waiting around 12 hours before applying power, it has been replaced. This is a cheapie eBay USB hub, of the type shown below.
The final part for the battery pack has finally arrived, the PCM boards. These modules protect the cells by cutting off the power at overcharge, undercharge & overcurrent. Each cell is connected individually on the right, 12v power appears on the left connections. These modules also ensure that all the
Continue readingWearable Raspberry Pi Part 2.5 – Battery Pack PCM
A few modifications were required to the SMPS modules to make the power rails stable enough to run the Pi & it’s monitor. Without these the rails were so noisy that instability was being caused. I have replaced the 100µF output capacitors & replaced them with 35v 4700µF caps. This
Progress is finally starting on the power supply unit for the Pi, fitted into the same case style as the Pi itself, this is an 8Ah Li-Poly battery pack with built in voltage regulation. Here are the regulators, fixed to the top of the enclosure. These provide the 12v &
For convenience, a pair of USB ports have been fitted to the wearable Pi, which open on the bottom of the unit. These will be hardwired into a 4-port USB hub which will also support the wireless adaptor for the mini-keyboard that is to be used with the device. The
Here is the project I’m currently working on. A completely wearable computing platform based on the Raspberry Pi & the WiFi Pineapple. Above can be seen the general overview of the current unit. On the left: Alfa AWUS036NHA USB High Power WiFi Network Interface 512MB Model B Raspberry Pi, 16GB
This will be the record of building a new Media PC, above you can see the finished system. It’s Mini-ITX based, with on-board HDMI output, specifically to run XBMC via Fedora for media purposes. This is the case that is being used, around the size of a Shuttle PC. It
This is a little script to make OMXPlayer on the Raspberry Pi cycle through every file in a specified folder, useful for playing sequential movies or series of episodes.
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#!/bin/bash if [ x"$1" = x"help" -o x"$1" = x"--help" -o x"$1" = x"-help" ];then echo "Usage: omxseries [audio mode] [folder path]" echo "Audio Mode can be either 'hdmi' or 'local'." echo "Folder Path is the full path to the video files on your system." echo "This script will attempt to play every file in the target folder, with any file extension," echo "so ensure that only valid video files are present in the target folder to avoid errors." exit fi |
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for file in $2/* do omxplayer -o $1 $file done |
Example: [root@raspbian ~]# omxseries hdmi /media/stuff/videos would play everything in /media/stuff/videos and send the audio over the HDMI port.
Above is the image projected from the Pi, on the default login screen. Distance from the projector is approx 10 feet. State of the art projector mount, fashioned from several cable ties. HDMI cable is plugged into the right hand side of the projector. Unfortunately the projector cannot handle audio
Here is a Sanyo tape recorder, with built in voice activation. Takes standard audio cassettes. Here visible is the speaker on the left, microphone is on the right of the tape window. The tape counter is at the top. Back cover removed from the unit, showing the PCB & the