@pamoja/gpio

I2C address frames with reserved-range checks, the four SPI clock modes, and active-high or active-low pins. One capability of pamoja, one memory-safe Rust core with bindings for TypeScript, Python, and C#.

Install

npm install @pamoja/gpio

This pulls in @pamoja/native, the compiled engine. npm install pamoja is the whole framework in one package.

Example

The test that runs in CI, spliced here as it ran.

From bindings/node/guides/gpio.ts:

// Most relay boards energize when their input is pulled low, and a float switch wired to
// ground closes the same way. Saying "active low" once, here, is what keeps the inversion
// out of every line below it.
const RELAY = PinPolarity.ActiveLow
const FLOAT = PinPolarity.ActiveLow
const pump = new Line()
const float = new Line([PinLevel.High, PinLevel.Low])
console.log(`a pump on an active-low relay runs when its line is ${pin.levelFor(RELAY, true)}`)

// The pump runs while the tank fills. The stand-in line answers open and then closed, so
// this is the real loop with nothing plugged in.
pump.drive(pin.levelFor(RELAY, true))
const whileFilling = pin.isAsserted(FLOAT, float.read())
const onceFilled = pin.isAsserted(FLOAT, float.read())
console.log(`the float reads full: ${whileFilling}, then ${onceFilled}`)

// The moment the float closes is that line going low, which is a falling edge. A watch
// armed for the rising one would sleep through the tank filling.
const closing = pin.triggers(PinEdge.Falling, PinLevel.High, PinLevel.Low)
console.log(`the float closing is a falling edge on that line: ${closing}`)

// Full, so the pump stops, and the levels the line was driven to are the whole
// conversation the board saw.
pump.drive(pin.levelFor(RELAY, false))
const [ran, stopped] = pump.driven
console.log(`running drove the line ${ran} and stopping drove it ${stopped}`)

// A part on a shared bus answers to an address, and the byte on the wire is not the
// address the datasheet prints: it shifts up one and the low bit says read or write.
const hex = (byte: number) => `0x${byte.toString(16).toUpperCase().padStart(2, '0')}`
const toWrite = i2c.addressFrame(0x76)[0]!
const toRead = i2c.addressFrame(0x76, { read: true })[0]!
console.log(`a part at 0x76 is written to as ${hex(toWrite)} and read from as ${hex(toRead)}`)

// Two ranges belong to the specification itself, so a part answering in either is a wiring
// mistake rather than a device.
const reserved = i2c.isReserved(i2c.RESERVED_FROM)
console.log(`${hex(i2c.RESERVED_FROM)} is reserved by the specification: ${reserved}`)

// And a datasheet quotes SPI's clock polarity and phase as one mode number.
const clock = spi.clockFor(3)
console.log(`SPI mode 3 idles high: ${clock.cpol}, samples on the trailing edge: ${clock.cpha}`)

The same capability in every language

| Language | Package | Reference | | --- | --- | --- | | Rust | pamoja-gpio | reference, docs.rs, install | | TypeScript | @pamoja/gpio | reference, install | | Python | pamoja-gpio | reference, install | | C# | Pamoja.Gpio | reference, install |

Documentation

• @pamoja/gpio reference, every class, function, and type this package exports.
• The I2C, SPI, and GPIO guide, with the same example in Rust, Python, and C#.
• Every capability, and the install page.

License

MIT