readLocator command response data
okoriko opened this issue · comments
Hi!
I've got some troubles with the readLocator response data.
Let's say I set the configuration as:
var opts = {
flags: 0x00,
x: 0x00FF, // x = 255 cm
y: 0x0000,
yawTare: 0x0
};
orb.configureLocator(opts);
I will get a 2 as xpos value the when I do:
orb.readLocator(function(err, data) {
if (err) {
console.log("error: ", err);
} else {
console.log("readLocator:");
console.log(" xpos:", data.xpos); // xpos is 2
console.log(" ypos:", data.ypos);
console.log(" xvel:", data.xvel);
console.log(" yvel:", data.yvel);
console.log(" sog:", data.sog);
}
});
I've looked at the response from ollie on the readLocator and the response itself looks wrong. It has the xpos set to 2 and xvel is to 25 (0x19):
<Buffer ff ff 00 01 0b 00 02 00 00 00 19 00 00 00 00 d8>
In parallel though, if I read the async packets, I can get the real value:
orb.on("async", function(response){
var xField = {from: 0, to: 2, type: 'signed'};
var yField = {from: 2, to: 4, type: 'signed'};
var x = Packet.prototype._parseField(xField, response.data); // x is 255
var y = Packet.prototype._parseField(yField, response.data);
console.log('pos:', x, y);
});
Not sure whether it matters but I am using a Ollie.
Does anyone know what might be going on, why am I getting the wrong data in the readLocator but correct position in the streaming/async packets?
Quick note: it looks like the iOS SDK is implementing the locator support using "odometer" and "velocity" data streaming:
https://github.com/orbotix/Sphero-iOS-SDK/blob/master/samples/Locator/Locator/ViewController.m#L100
And by reading the position from the async packets:
https://github.com/orbotix/Sphero-iOS-SDK/blob/master/samples/Locator/Locator/ViewController.m#L110
It might be the way to go with this?
It still does not explain the behavior on the readlocator response though.
This might not answering your question, but I am calling the odometer to get the x and y positions [1]. I was fiddling with readLocator before but found that they gave the same values for xpos and ypos; although calling the odometer seems way simpler.
[1] https://github.com/orbotix/sphero.js/blob/master/examples/stream-odometer.js
