From eae601a04d1f1efe75b174b0bde919f5a0025738 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A1s=20Retzler?= Date: Sun, 8 Nov 2015 14:41:57 +0100 Subject: [PATCH] Update README.md --- README.md | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/README.md b/README.md index 7e79ee4..0bfa756 100644 --- a/README.md +++ b/README.md @@ -15,14 +15,16 @@ Note that it should be already done, if you installed *qtcsdr*. ### Modulate from raw audio file -Generate AM modulation: - - cat testsound48000.raw | csdr convert_i16_f | csdr gain_ff 1.0 | csdr dsb_fc | csdr add_dcoffset_cc | sudo rpitx -i- -m IQFLOAT -f 28400 - -* It will read the raw audio file `testsound48000.raw`, which is present in this repo. You can get this file by: +These examples will use the raw audio file `testsound48000.raw`, which is present in this repo. You can get this file by: git clone https://github.com/ha7ilm/rpitx-app-note - cd rpitx-app-note; ls #There is your file. + cd rpitx-app-note; ls #There is your file. + +A raw audio file differs from a .wav file because it doesn't have any headers to store its parameters, just the samples after each other. + +**Generate AM modulation:** + + cat testsound48000.raw | csdr convert_i16_f | csdr gain_ff 1.0 | csdr dsb_fc | csdr add_dcoffset_cc | sudo rpitx -i- -m IQFLOAT -f 28400 * The part `csdr gain_ff 1.0` can be changed to increase/decrease modulation. * The `-f 28400` at the end gives the transmit frequency in kHz.