From 26c50b42789b671f0483f1de6c2ec2b5fbb7afde Mon Sep 17 00:00:00 2001
From: c vw <dl1ycf@darc.de>
Date: Tue, 4 Aug 2020 16:05:46 +0200
Subject: [PATCH] HermesLite2 PS feedback update
---
old_protocol.c | 40 ++++++++++++++++++++++++++++++++--------
1 file changed, 32 insertions(+), 8 deletions(-)
diff --git a/old_protocol.c b/old_protocol.c
index ffabfb8..dc03359 100644
--- a/old_protocol.c
+++ b/old_protocol.c
@@ -1465,11 +1465,24 @@ static int last_power=0;
// encode all 6 bits of RXgain in ATT value and set bit6
if (isTransmitting()) {
//
- // Set the preamp to (19-TXatt) dB (+19 ... â12 dB)
- // temporary change: use more amplification to allow PURESIGNAL on
- // a barefoot HL2 with "cross talk" feedback from the TRX relay
+ // The "TX attenuation" value (0 ... 31 dB) has to be mapped to a
+ // a range of preamp settings. This range is very different on the
+ // HermesLite when using "internal" feedback (crosstalk from the
+ // RX/TX releay) or "external" feedback (attenuator output
+ // connected with RF3 input of the HermesLite2).
+ // To cope with both situations, the preamp range is
+ // +2 ... +33 dB if "Internal" feedback is selected in the
+ // PS menu (this is optimal for "crosstalk" feedback) and
+ // if external feedback is used (check either EXT1 or ByPass
+ // in the PS menu) the preamp range is -12 ... +19 dB.
//
- output_buffer[C4] = 0x40 | (45 - (transmitter->attenuation & 0x1F));
+ //
+ output_buffer[C4] = 0x40 | (33 - (transmitter->attenuation & 0x1F));
+#ifdef PURESIGNAL
+ if (receiver[PS_RX_FEEDBACK]->alex_antenna == 0) {
+ output_buffer[C4] = 0x40 | (45 - (transmitter->attenuation & 0x1F));
+ }
+#endif
} else {
output_buffer[C4] = 0x40 | (rxgain & 0x3F);
}
@@ -1525,10 +1538,21 @@ static int last_power=0;
output_buffer[C1]|=(receiver[1]->adc<<(2*rx2channel));
}
}
- output_buffer[C3]=0x00;
- // this is a no-op on the HermesLite2 which needs b7 set to make this effective
- // no need to bother here since we do this manually (see above)
- output_buffer[C3]|=transmitter->attenuation & 0x1F; // Step attenuator of first ADC, value used when TXing
+ if (have_rx_gain) {
+ //
+ // On the HermesLite2, we need bit7 set to make this feature active,
+ // and need bit6 set to tell HL2 to directly use the lowest 6 bits
+ // for the built-in preamp. For the effect of choosing different
+ // "alex antennas" see above.
+ output_buffer[C3] = 0xC0 | (33 - (transmitter->attenuation & 0x1F));
+#ifdef PURESIGNAL
+ if (receiver[PS_RX_FEEDBACK]->alex_antenna == 0) {
+ output_buffer[C3] = 0xC0 | (45 - (transmitter->attenuation & 0x1F));
+ }
+#endif
+ } else {
+ output_buffer[C3]=transmitter->attenuation & 0x1F; // Step attenuator of first ADC, value used when TXing
+ }
output_buffer[C4]=0x00;
break;
case 7:
--
2.45.2