exercises: add Exercise 07 SD startup watcher with OLED status and hot-insert/removal handling

This commit is contained in:
John Poole 2026-02-15 12:25:03 -08:00
commit 2aec641fc2
7 changed files with 672 additions and 0 deletions

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#include "StartupSdManager.h"
#include <stdarg.h>
#include "driver/gpio.h"
StartupSdManager::StartupSdManager(Print& serial) : serial_(serial) {}
bool StartupSdManager::begin(const SdWatcherConfig& cfg, SdStatusCallback callback) {
cfg_ = cfg;
callback_ = callback;
forceSpiDeselected();
dumpSdPins("very-early");
if (!initPmuForSdPower()) {
return false;
}
cycleSdRail();
delay(cfg_.startupWarmupMs);
bool warmMounted = false;
for (uint8_t i = 0; i < 3; ++i) {
if (mountPreferred(false)) {
warmMounted = true;
break;
}
delay(200);
}
if (warmMounted) {
setStateMounted();
} else {
setStateAbsent();
}
return true;
}
void StartupSdManager::update() {
const uint32_t now = millis();
const uint32_t pollInterval =
(watchState_ == SdWatchState::MOUNTED) ? cfg_.pollIntervalMountedMs : cfg_.pollIntervalAbsentMs;
if ((uint32_t)(now - lastPollMs_) < pollInterval) {
return;
}
lastPollMs_ = now;
if (watchState_ == SdWatchState::MOUNTED) {
if (verifyMountedCard()) {
presentVotes_ = 0;
absentVotes_ = 0;
return;
}
if (mountPreferred(false) && verifyMountedCard()) {
presentVotes_ = 0;
absentVotes_ = 0;
return;
}
absentVotes_++;
presentVotes_ = 0;
if (absentVotes_ >= cfg_.votesToAbsent) {
setStateAbsent();
absentVotes_ = 0;
}
return;
}
bool mounted = mountPreferred(false);
if (!mounted && (uint32_t)(now - lastFullScanMs_) >= cfg_.fullScanIntervalMs) {
lastFullScanMs_ = now;
logf("Watcher: preferred probe failed, running full scan");
mounted = mountCardFullScan();
}
if (mounted) {
presentVotes_++;
absentVotes_ = 0;
if (presentVotes_ >= cfg_.votesToPresent) {
setStateMounted();
presentVotes_ = 0;
}
} else {
absentVotes_++;
presentVotes_ = 0;
if (absentVotes_ >= cfg_.votesToAbsent) {
setStateAbsent();
absentVotes_ = 0;
}
}
}
bool StartupSdManager::consumeMountedEvent() {
bool out = mountedEventPending_;
mountedEventPending_ = false;
return out;
}
bool StartupSdManager::consumeRemovedEvent() {
bool out = removedEventPending_;
removedEventPending_ = false;
return out;
}
void StartupSdManager::logf(const char* fmt, ...) {
char msg[196];
va_list args;
va_start(args, fmt);
vsnprintf(msg, sizeof(msg), fmt, args);
va_end(args);
serial_.printf("[%10lu][%06lu] %s\r\n",
(unsigned long)millis(),
(unsigned long)logSeq_++,
msg);
}
void StartupSdManager::notify(SdEvent event, const char* message) {
if (callback_ != nullptr) {
callback_(event, message);
}
}
void StartupSdManager::forceSpiDeselected() {
pinMode(tbeam_supreme::sdCs(), OUTPUT);
digitalWrite(tbeam_supreme::sdCs(), HIGH);
pinMode(tbeam_supreme::imuCs(), OUTPUT);
digitalWrite(tbeam_supreme::imuCs(), HIGH);
}
void StartupSdManager::dumpSdPins(const char* tag) {
if (!cfg_.enablePinDumps) {
(void)tag;
return;
}
const gpio_num_t cs = (gpio_num_t)tbeam_supreme::sdCs();
const gpio_num_t sck = (gpio_num_t)tbeam_supreme::sdSck();
const gpio_num_t miso = (gpio_num_t)tbeam_supreme::sdMiso();
const gpio_num_t mosi = (gpio_num_t)tbeam_supreme::sdMosi();
logf("PINS(%s): CS=%d SCK=%d MISO=%d MOSI=%d",
tag, gpio_get_level(cs), gpio_get_level(sck), gpio_get_level(miso), gpio_get_level(mosi));
}
bool StartupSdManager::initPmuForSdPower() {
if (!tbeam_supreme::initPmuForPeripherals(pmu_, &serial_)) {
logf("ERROR: PMU init failed");
return false;
}
return true;
}
void StartupSdManager::cycleSdRail(uint32_t offMs, uint32_t onSettleMs) {
if (!cfg_.enableSdRailCycle) {
return;
}
if (!pmu_) {
logf("SD rail cycle skipped: pmu=null");
return;
}
forceSpiDeselected();
pmu_->disablePowerOutput(XPOWERS_BLDO1);
delay(offMs);
pmu_->setPowerChannelVoltage(XPOWERS_BLDO1, 3300);
pmu_->enablePowerOutput(XPOWERS_BLDO1);
delay(onSettleMs);
}
bool StartupSdManager::tryMountWithBus(SPIClass& bus, const char* busName, uint32_t hz, bool verbose) {
SD.end();
bus.end();
delay(10);
forceSpiDeselected();
bus.begin(tbeam_supreme::sdSck(), tbeam_supreme::sdMiso(), tbeam_supreme::sdMosi(), tbeam_supreme::sdCs());
digitalWrite(tbeam_supreme::sdCs(), HIGH);
delay(2);
for (int i = 0; i < 10; i++) {
bus.transfer(0xFF);
}
delay(2);
if (verbose) {
logf("SD: trying bus=%s freq=%lu Hz", busName, (unsigned long)hz);
}
if (!SD.begin(tbeam_supreme::sdCs(), bus, hz)) {
if (verbose) {
logf("SD: mount failed");
}
return false;
}
if (SD.cardType() == CARD_NONE) {
SD.end();
return false;
}
sdSpi_ = &bus;
sdBusName_ = busName;
sdFreq_ = hz;
return true;
}
bool StartupSdManager::mountPreferred(bool verbose) {
return tryMountWithBus(sdSpiH_, "HSPI", 400000, verbose);
}
bool StartupSdManager::mountCardFullScan() {
const uint32_t freqs[] = {400000, 1000000, 4000000, 10000000};
for (uint8_t i = 0; i < (sizeof(freqs) / sizeof(freqs[0])); ++i) {
if (tryMountWithBus(sdSpiH_, "HSPI", freqs[i], true)) {
logf("SD: card detected and mounted");
return true;
}
}
for (uint8_t i = 0; i < (sizeof(freqs) / sizeof(freqs[0])); ++i) {
if (tryMountWithBus(sdSpiF_, "FSPI", freqs[i], true)) {
logf("SD: card detected and mounted");
return true;
}
}
logf("SD: begin() failed on all bus/frequency attempts");
return false;
}
bool StartupSdManager::verifyMountedCard() {
File root = SD.open("/", FILE_READ);
if (!root) {
return false;
}
root.close();
return true;
}
const char* StartupSdManager::cardTypeToString(uint8_t type) {
switch (type) {
case CARD_MMC:
return "MMC";
case CARD_SD:
return "SDSC";
case CARD_SDHC:
return "SDHC/SDXC";
default:
return "UNKNOWN";
}
}
void StartupSdManager::printCardInfo() {
uint8_t cardType = SD.cardType();
uint64_t cardSizeMB = SD.cardSize() / (1024ULL * 1024ULL);
uint64_t totalMB = SD.totalBytes() / (1024ULL * 1024ULL);
uint64_t usedMB = SD.usedBytes() / (1024ULL * 1024ULL);
logf("SD type: %s", cardTypeToString(cardType));
logf("SD size: %llu MB", cardSizeMB);
logf("FS total: %llu MB", totalMB);
logf("FS used : %llu MB", usedMB);
logf("SPI bus: %s @ %lu Hz", sdBusName_, (unsigned long)sdFreq_);
}
bool StartupSdManager::ensureDirRecursive(const char* path) {
String full(path);
if (!full.startsWith("/")) {
full = "/" + full;
}
int start = 1;
while (start > 0 && start < (int)full.length()) {
int slash = full.indexOf('/', start);
String partial = (slash < 0) ? full : full.substring(0, slash);
if (!SD.exists(partial.c_str()) && !SD.mkdir(partial.c_str())) {
logf("ERROR: mkdir failed for %s", partial.c_str());
return false;
}
if (slash < 0) {
break;
}
start = slash + 1;
}
return true;
}
bool StartupSdManager::rewriteFile(const char* path, const char* payload) {
if (SD.exists(path) && !SD.remove(path)) {
logf("ERROR: failed to erase %s", path);
return false;
}
File f = SD.open(path, FILE_WRITE);
if (!f) {
logf("ERROR: failed to create %s", path);
return false;
}
size_t wrote = f.println(payload);
f.close();
if (wrote == 0) {
logf("ERROR: write failed for %s", path);
return false;
}
return true;
}
void StartupSdManager::permissionsDemo(const char* path) {
logf("Permissions demo: FAT has no Unix chmod/chown, use open mode only.");
File r = SD.open(path, FILE_READ);
if (!r) {
logf("Could not open %s as FILE_READ", path);
return;
}
size_t writeInReadMode = r.print("attempt write while opened read-only");
if (writeInReadMode == 0) {
logf("As expected, FILE_READ write was blocked.");
} else {
logf("NOTE: FILE_READ write returned %u (unexpected)", (unsigned)writeInReadMode);
}
r.close();
}
void StartupSdManager::setStateMounted() {
if (watchState_ != SdWatchState::MOUNTED) {
logf("EVENT: card inserted/mounted");
mountedEventPending_ = true;
notify(SdEvent::CARD_MOUNTED, "SD card mounted");
}
watchState_ = SdWatchState::MOUNTED;
}
void StartupSdManager::setStateAbsent() {
if (watchState_ == SdWatchState::MOUNTED) {
logf("EVENT: card removed/unavailable");
removedEventPending_ = true;
notify(SdEvent::CARD_REMOVED, "SD card removed");
} else if (watchState_ != SdWatchState::ABSENT) {
logf("EVENT: no card detected");
notify(SdEvent::NO_CARD, "Missing SD card / Please insert card to proceed");
}
SD.end();
watchState_ = SdWatchState::ABSENT;
}

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#pragma once
#include <Arduino.h>
#include <SD.h>
#include <SPI.h>
#include <Wire.h>
#include "tbeam_supreme_adapter.h"
enum class SdWatchState : uint8_t {
UNKNOWN = 0,
ABSENT,
MOUNTED
};
enum class SdEvent : uint8_t {
NO_CARD,
CARD_MOUNTED,
CARD_REMOVED
};
using SdStatusCallback = void (*)(SdEvent event, const char* message);
struct SdWatcherConfig {
bool enableSdRailCycle = true;
bool enablePinDumps = true;
uint32_t startupWarmupMs = 1500;
uint32_t pollIntervalAbsentMs = 1000;
uint32_t pollIntervalMountedMs = 2000;
uint32_t fullScanIntervalMs = 10000;
uint8_t votesToPresent = 2;
uint8_t votesToAbsent = 5;
};
class StartupSdManager {
public:
explicit StartupSdManager(Print& serial = Serial);
bool begin(const SdWatcherConfig& cfg, SdStatusCallback callback = nullptr);
void update();
bool isMounted() const { return watchState_ == SdWatchState::MOUNTED; }
SdWatchState state() const { return watchState_; }
bool consumeMountedEvent();
bool consumeRemovedEvent();
void printCardInfo();
bool ensureDirRecursive(const char* path);
bool rewriteFile(const char* path, const char* payload);
void permissionsDemo(const char* path);
private:
void logf(const char* fmt, ...);
void notify(SdEvent event, const char* message);
void forceSpiDeselected();
void dumpSdPins(const char* tag);
bool initPmuForSdPower();
void cycleSdRail(uint32_t offMs = 250, uint32_t onSettleMs = 600);
bool tryMountWithBus(SPIClass& bus, const char* busName, uint32_t hz, bool verbose);
bool mountPreferred(bool verbose);
bool mountCardFullScan();
bool verifyMountedCard();
const char* cardTypeToString(uint8_t type);
void setStateMounted();
void setStateAbsent();
Print& serial_;
SdWatcherConfig cfg_{};
SdStatusCallback callback_ = nullptr;
SPIClass sdSpiH_{HSPI};
SPIClass sdSpiF_{FSPI};
SPIClass* sdSpi_ = nullptr;
const char* sdBusName_ = "none";
uint32_t sdFreq_ = 0;
XPowersLibInterface* pmu_ = nullptr;
SdWatchState watchState_ = SdWatchState::UNKNOWN;
uint8_t presentVotes_ = 0;
uint8_t absentVotes_ = 0;
uint32_t lastPollMs_ = 0;
uint32_t lastFullScanMs_ = 0;
uint32_t logSeq_ = 0;
bool mountedEventPending_ = false;
bool removedEventPending_ = false;
};

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{
"name": "startup_sd",
"version": "0.1.0",
"dependencies": [
{
"name": "XPowersLib"
},
{
"name": "Wire"
}
]
}