michele/DigiRadio
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Fix Si4684 FM/DAB tune commands: ARG offset bug caused total RF blackout

Browse Source 
writeCommand() always prepends a fixed ARG1=0x00 byte before the payload;
tuneFm()/tuneDab() built their argument arrays starting at what the author
believed was ARG1, so every byte landed one slot right of its real AN649
position and an extra unused byte was appended. The chip never received the
requested frequency. This is the root cause of the months-long total RF
blackout (RSQ frozen at all-zero on every frequency/ANTCAP value) previously
attributed to a QFN exposed-pad hardware defect — that hypothesis is now
overturned, confirmed live: RSSI/SNR now read real, frequency-dependent
values with zero STC timeouts after the fix.

Also make BT1035 boot failure non-fatal in HardwareBootstrap::boot() so a
companion-chip fault no longer halts the whole device (Si4684 tuning, web
UI, Wi-Fi already isolate BT1035 readiness via CompanionChipStatus).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0178rASQ6ZETPMUamvpoR2KR
This commit is contained in:
michele
2026-08-16 00:19:43 +02:00
co-authored by Claude Sonnet 5
parent bc1b1b1472
commit ef15e9839c
3 changed files with 200 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files
Software/components/drivers/si4684/src/Si4684Driver.cpp
+9 -2
View File
@@ -742,8 +742,12 @@ std::expected<void, Si4684Error> Si4684Driver::tuneFm(
return cleared;
}
const std::uint16_t chipFreq = kHzToChipFmFreq(frequency.value());
// writeCommand() always prepends a fixed ARG1=0x00 (DIR_TUNE=0,
// TUNE_MODE=0, INJECTION=0), so this array starts at ARG2 (AN649
// Command 0x30 table: ARG2=FREQ[7:0], ARG3=FREQ[15:8], ARG4=ANTCAP[7:0],
// ARG5=ANTCAP[15:8], ARG6=PROG_ID). Do not add a leading/trailing byte
// here or every field shifts into the wrong ARG slot.
const std::uint8_t args[] = {
0x00U,
static_cast<std::uint8_t>(chipFreq & 0xFFU),
static_cast<std::uint8_t>(chipFreq >> 8),
antCap, // ANTCAP[7:0] -- 0 = auto (FE_VARM/VARB), else forced value
@@ -1005,7 +1009,10 @@ std::expected<void, Si4684Error> Si4684Driver::tuneDab(std::uint8_t freqIndex)
if (freqIndex >= kDefaultDabFrequencyKhz.size()) {
return std::unexpected(Si4684Error::TuneFailed);
}
const std::uint8_t args[] = {0x00U, freqIndex, 0x00U, 0x00U, 0x00U};
// writeCommand() always prepends a fixed ARG1=0x00 (INJECTION=0), so
// this array starts at ARG2 (AN649 Command 0xB0 table: ARG2=FREQ_INDEX,
// ARG3=0x00 fixed, ARG4=ANTCAP[7:0], ARG5=ANTCAP[15:8]).
const std::uint8_t args[] = {freqIndex, 0x00U, 0x00U, 0x00U};
if (auto cmd = writeCommand(Command::DabTuneFreq, args, sizeof(args));
!cmd) {
return std::unexpected(Si4684Error::TuneFailed);