Search found 14 matches

by raphik
Sat Mar 25, 2017 2:47 am
Forum: Projects
Topic: Display and control buttons for a web radio
Replies: 1
Views: 321

Display and control buttons for a web radio

Several years ago I went into Jeff Keyzer's project consisting on recycling a discarded, Linux capable router into a wifi web radio. I built one, but lacking an LCD display and a tuning control. So now I would like to incorporate a screen and some buttons to operate my radio. Buttons and display wou...
by raphik
Wed Mar 15, 2017 5:45 pm
Forum: Postbag
Topic: Raphik's postbag
Replies: 1
Views: 291

Raphik's postbag

As part of my last order (my stm32duino is missing!), I have just received a pretty MB102 kit. http://i.imgur.com/PPfHZ24.jpg As seen on the picture, it consists on an 830 point solderless breadboard, a 700mA power supply and a bunch of 65 male jumper cables. I know this is basic, but it's my very f...
by raphik
Wed Mar 01, 2017 10:37 pm
Forum: Postbag
Topic: Rogers postbag
Replies: 94
Views: 6144

Re: Rogers postbag - FM radio band transmitter

Yep, it's orange. In addition, I measured it with the polymeter as well.
by raphik
Wed Mar 01, 2017 9:48 pm
Forum: Postbag
Topic: Rogers postbag
Replies: 94
Views: 6144

Re: Rogers postbag - FM radio band transmitter

There are actually one main carrier and up to three extra subcarriers. In the beginning FM used to be quite a simple wave. But then, FM Stereo came and a 19 KHz pilot signal and an extra subcarrier was added at 38 KHz just to carry the so named subtraction channel (L - R). Older receivers precess on...
by raphik
Tue Feb 28, 2017 11:59 pm
Forum: Postbag
Topic: Rogers postbag
Replies: 94
Views: 6144

Re: Rogers postbag - FM radio band transmitter

I don't have an RDS radio but I do have one of those TV dongles that work as SDR (Software Defined Radio), and I know some of the SDR software can display the data that is in the FM signal I suspect that would be the easiest way to debug any RDS data. I am displaying RDS data on my laptop using the...
by raphik
Thu Feb 23, 2017 8:48 am
Forum: Postbag
Topic: Rogers postbag
Replies: 94
Views: 6144

Re: Rogers postbag - FM radio band transmitter

@ RogerClark. I have also a DVB dongle RTL-SDR capable. A suitable RDS spy software is crucial for displaying miss-built RDS packages. I understand that standard receptors discard wrong packages.

@ Vassilis. Geia sou. Nice purchase! Let's know when you receive the parcel.
by raphik
Wed Feb 22, 2017 10:52 pm
Forum: Postbag
Topic: Rogers postbag
Replies: 94
Views: 6144

Re: Rogers postbag - FM radio band transmitter

Well, the truth is that the QN8027 IC has few, boring programmable features: initialization, calibration, frequency and emission power. The one really interesting thing is the sending of data via RDS. RDS data packages must match a particular, given structure before being sent. Otherwise receivers w...
by raphik
Wed Feb 22, 2017 11:57 am
Forum: Postbag
Topic: Rogers postbag
Replies: 94
Views: 6144

Bare but ready-to-use FM radio band transmitter

I would like to link this FM transmitter module to my next-to-be-bought STM32 MCU through its i2c bus. But having the 8027 IC SDA and SCL pins welded to its original board is a bit annoying because of the interferences with onboard "JL MCU". So one can think buying a bare QN8027 could be a good idea...
by raphik
Sun Feb 19, 2017 4:44 am
Forum: Postbag
Topic: Rogers postbag
Replies: 94
Views: 6144

Re: Rogers postbag - FM radio band transmitter

@RogerClark I soldered a pair of wires to a couple of spare GPIOs on the board. Those GPIO were thought for a pair of LEDs that the builder never put on the board. http://i.imgur.com/VtlRSZv.jpg Then I took the wires out and connected them to an I2C expansor. http://i.imgur.com/mLvj5ID.jpg For the s...
by raphik
Sun Feb 19, 2017 12:54 am
Forum: Postbag
Topic: Rogers postbag
Replies: 94
Views: 6144

Re: Rogers postbag - FM radio band transmitter

@ RogerClark Congrats for finishing your BT2FM project! I finally succeeded to connect my MCU (an OpenWRT router) with the FM board. It is important to let both devices start before connecting their i2c buses in order to avoid collisions. i2cdetect detects QN8027 on address 0x2c, just where it was s...