Today I had some time to play around with a esp32-c6 I had laying around. I wondered for a while now whether it would be possible to run Diesel on these micro controllers.
Turns out that this is possible for the SQLite backend with some adjustments to diesel and some of our dependencies :tada:
You still need to bring your own VFS to get this working.
I likely will upstream parts of these in the next days, so the next Diesel release might support this out of the box.
![Source code for running an embedded Rust program creating a Sqlite Database connection via Diesel and executing several queries.
```rust
#[unsafe(no_mangle)]
extern "C" fn sqlite3_os_init() -> core::ffi::c_int {
println!("Setup os");
unsafe {
crate::memory::install();
}
libsqlite3_sys::SQLITE_OK
}
#[esp_hal::main]
fn main() -> ! {
let config = esp_hal::Config::default().with_cpu_clock(esp_hal::clock::CpuClock::max());
let peripherals = esp_hal::init(config);
println!("Firmware starting");
esp_alloc::heap_allocator!(size: 100 * 1024);
println!("Before sqlite");
let mut conn = SqliteConnection::establish(":memory:").unwrap();
conn.set_instrumentation(|event: diesel::connection::InstrumentationEvent<'_>| {
println!("Execute query: {event:?}")
});
conn.batch_execute("CREATE TABLE users(id INTEGER NOT NULL PRIMARY KEY, name TEXT NOT NULL)")
.unwrap();
diesel::insert_into(users::table)
.values([users::name.eq("John"), users::name.eq("Jane")])
.execute(&mut conn)
.unwrap();
let delay = Delay::new();
loop {
let data = users::table
.filter(users::name.eq("Jane"))
.first::<(i32, String)>(&mut conn)
.unwrap();
println!("----");
println!("Query data:");
println!("Loaded user data: {} -> {}", data.0, data.1);
println!("---");
delay.delay_millis(500);
}
}
```](https://social.weiznich.de/system/media_attachments/files/115/674/254/327/314/311/original/821f1497450d7ba0.png)