From 8c54e6400be411307e1e0c6068ed4c0254c20c9c Mon Sep 17 00:00:00 2001
From: Ramakrishnan Muthukrishnan <ram@rkrishnan.org>
Date: Sat, 13 Aug 2022 21:51:00 +0530
Subject: [PATCH] drive level is sent in the upper 4 bits
Fix from DL1YCF pihpsdr fork.
---
old_protocol.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 56 insertions(+), 1 deletion(-)
diff --git a/old_protocol.c b/old_protocol.c
index e84da5c..8d31e20 100644
--- a/old_protocol.c
+++ b/old_protocol.c
@@ -1646,7 +1646,7 @@ void ozy_send_buffer() {
{
BAND *band=band_get_current_band();
int power=0;
-static int last_power=0;
+ static int last_power=0;
//
// Some HPSDR apps for the RedPitaya generate CW inside the FPGA, but while
// doing this, DriveLevel changes are processed by the server, but do not become effective.
@@ -1663,6 +1663,61 @@ static int last_power=0;
} else {
power=transmitter->drive_level;
}
+
+ if (device == DEVICE_HERMES_LITE2) {
+ //
+ // from the "intended" drive level power, calculate the
+ // next lower TX attenuation which can be from 0.0 to -7.5 dB
+ // in 0.5 dB steps, encode the step in a four-bit word and shift
+ // it to the upper 4 bits.
+ // we always use the att level that produces a little bit *less* attenuation
+ // than required, and down-scale the IQ samples in transmitter.c
+ //
+ // NOTE: this down-scaling does not occur when connecting a CW key to the HL2
+ // and using "internal" CW, because in this case the IQ samples are
+ // generated in the FPGA. A typical symptom is that the CW signals are
+ // stronger than the "TUNE" signal, and in the case of very low drive slider
+ // values they can be *much* stronger.
+ //
+ // NOTE: When using predistortion (PURESIGNAL), the IQ scaling must be switched off.
+ // In this case, the output power can also be stronger than intended.
+ //
+ int hl2power;
+ if (power < 102) {
+ hl2power=0; // -7.5 dB TX attenuation
+ } else if (power < 108) {
+ hl2power=16; // -7.0 dB TX attenuation
+ } else if (power < 114) {
+ hl2power=32; // -6.5 dB TX attenuation
+ } else if (power < 121) {
+ hl2power=48; // -6.0 dB TX attenuation
+ } else if (power < 128) {
+ hl2power=64; // -5.5 dB TX attenuation
+ } else if (power < 136) {
+ hl2power=80; // -5.0 dB TX attenuation
+ } else if (power < 144) {
+ hl2power=96; // -4.5 dB TX attenuation
+ } else if (power < 152) {
+ hl2power=112; // -4.0 dB TX attenuation
+ } else if (power < 161) {
+ hl2power=128; // -3.5 dB TX attenuation
+ } else if (power < 171) {
+ hl2power=144; // -3.0 dB TX attenuation
+ } else if (power < 181) {
+ hl2power=160; // -2.5 dB TX attenuation
+ } else if (power < 192) {
+ hl2power=176; // -2.0 dB TX attenuation
+ } else if (power < 203) {
+ hl2power=192; // -1.5 dB TX attenuation
+ } else if (power < 215) {
+ hl2power=208; // -1.0 dB TX attenuation
+ } else if (power < 228) {
+ hl2power=224; // -0.5 dB TX attenuation
+ } else {
+ hl2power=240; // no TX attenuation
+ }
+ power=hl2power;
+ }
}
//if(last_power!=power) {
--
2.45.2