Pros of JerryScript

• More actively maintained with frequent updates and contributions
• Broader platform support, including various embedded systems and IoT devices
• Comprehensive documentation and examples for easier integration

Cons of JerryScript

• Larger memory footprint compared to V7
• More complex build system and configuration process
• Steeper learning curve for developers new to embedded JavaScript engines

Code Comparison

V7:

v7_val_t v7_mk_function(struct v7 *v7, v7_cfunction_t *func) {
  return v7_mk_cfunction(v7, func);
}

JerryScript:

jerry_value_t jerry_create_external_function(jerry_external_handler_t handler) {
  return jerry_create_external_function_with_data(handler, NULL);
}

Both engines provide similar functionality for creating JavaScript functions from C code, but JerryScript offers more flexibility with additional parameters and options.

Pros of Espruino

• More active development and larger community support
• Designed specifically for microcontrollers, with optimized performance
• Extensive documentation and examples for hardware integration

Cons of Espruino

• Larger codebase and memory footprint
• Less suitable for general-purpose embedded scripting
• Steeper learning curve for developers not familiar with microcontroller programming

Code Comparison

Espruino:

var led = LED1;
setInterval(function() {
  led.toggle();
}, 500);

v7:

v7_val_t blink(struct v7 *v7) {
  gpio_toggle(LED_PIN);
  return v7_mk_undefined();
}
v7_set_method(v7, v7_get_global(v7), "blink", blink);

Summary

Espruino is tailored for microcontroller programming with JavaScript, offering extensive hardware support and documentation. v7 is a more lightweight, general-purpose embedded scripting engine. Espruino provides a more accessible API for hardware interaction, while v7 offers a smaller footprint and broader application scope. The choice between them depends on the specific project requirements, target hardware, and developer expertise.

Pros of MicroPython

• More extensive standard library and built-in modules
• Larger community and ecosystem with better documentation
• Supports a wider range of microcontrollers and development boards

Cons of MicroPython

• Larger memory footprint, requiring more resources on embedded devices
• Slower execution speed for certain operations compared to V7

Code Comparison

MicroPython:

import machine
import time

led = machine.Pin(2, machine.Pin.OUT)
while True:
    led.value(not led.value())
    time.sleep(0.5)

V7:

#include "v7.h"
#include "gpio.h"

void blink(struct v7 *v7) {
  gpio_toggle(2);
  v7_exec(v7, "setTimeout(blink, 500);");
}

The MicroPython code is more readable and Pythonic, while the V7 code is more C-like and requires lower-level programming knowledge. MicroPython provides a higher-level abstraction, making it easier for beginners to work with embedded systems. V7, on the other hand, offers more direct control over hardware and potentially better performance for resource-constrained devices.