Invalid value for battery charge. NaN

[Daveblanche]

Hi there This plugin is just what I’m after. Something to tell me when my house IT falls down and I can tell my wife to shut things down…whilst I’m working in a foreign country. But I have a wee snag in that I can’t get it to work. Can I send you a debug report so you could tell me what I’ve done wrong? Probably best if I can send it to you direct as I do bones not computers. Not sure how to run through everything and anonymise it.

[cr3ative]

Sure, attach a log and I'll take a look - no promises though!

If you also wouldn't mind just running apcaccess on the command line too, so I can see what it's putting out for the charge value, that'd be great.

[upcsymbol]

This fixed for me

    // BCHARGE
    const percentage = parseFloat(parseInt(this.latestJSON.BCHARGE, 10));

[cr3ative]

Hm, that shouldn't make a difference - if parseInt fails, parseFloat would too, even wrapped. I'm very happy to publish a new version if someone can tell me what BCHARGE is set to.

For now, I'll see about catching this and reporting zero, so it's within tolerances.

[cr3ative]

I've published 0.11, which should output some useful debug, and set the charge level to zero if it's NaN:

https://github.com/cr3ative/homebridge-apcaccess/blob/master/index.js#L70

[upcsymbol]

I've published 0.11, which should output some useful debug, and set the charge level to zero if it's NaN:

https://github.com/cr3ative/homebridge-apcaccess/blob/master/index.js#L70

Results

[10/1/2022, 4:10:06 PM] [UPS] Low Battery?  BATTERY_LEVEL_NORMAL
[10/1/2022, 4:10:06 PM] [UPS] Battery level NaN problem; recorded as  undefined false
[10/1/2022, 4:10:06 PM] [homebridge-apcaccess] This plugin threw an error from the characteristic 'Battery Level': Unhandled error thrown inside read handler for characteristic: Assignment to constant variable.. See https://homebridge.io/w/JtMGR for more info.
[10/1/2022, 4:10:06 PM] [homebridge-apcaccess] TypeError: Assignment to constant variable.
    at APCAccess.getBatteryLevel (/usr/local/lib/node_modules/homebridge-apcaccess/index.js:72:18)
    at BatteryLevel.emit (node:events:526:28)
    at /usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/src/lib/Characteristic.ts:1592:14
    at new Promise (<anonymous>)
    at BatteryLevel.<anonymous> (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/src/lib/Characteristic.ts:1590:12)
    at step (/usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:144:27)
    at Object.next (/usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:125:57)
    at /usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:118:75
    at new Promise (<anonymous>)
    at __awaiter (/usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:114:16)
    at BatteryLevel.Characteristic.handleGetRequest (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/dist/lib/Characteristic.js:689:38)
    at BatteryLevel.<anonymous> (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/src/lib/Characteristic.ts:2207:22)
    at step (/usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:144:27)
    at Object.next (/usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:125:57)
    at /usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:118:75
    at new Promise (<anonymous>)
[10/1/2022, 4:10:06 PM] [UPS] Charging state:  CHARGING

[cr3ative]

Oh that’s fun. I’ve made an obvious code mistake, but also the JSON object coming through to parse is completely blank. Ok! I’ll look at this on Monday. On 1 Oct 2022, at 21:14, upcsymbol @.***> wrote:

I've published 0.11, which should output some useful debug, and set the charge level to zero if it's NaN: https://github.com/cr3ative/homebridge-apcaccess/blob/master/index.js#L70

Results [10/1/2022, 4:10:06 PM] [UPS] Low Battery? BATTERY_LEVEL_NORMAL [10/1/2022, 4:10:06 PM] [UPS] Battery level NaN problem; recorded as undefined false [10/1/2022, 4:10:06 PM] [homebridge-apcaccess] This plugin threw an error from the characteristic 'Battery Level': Unhandled error thrown inside read handler for characteristic: Assignment to constant variable.. See https://homebridge.io/w/JtMGR for more info. [10/1/2022, 4:10:06 PM] [homebridge-apcaccess] TypeError: Assignment to constant variable. at APCAccess.getBatteryLevel (/usr/local/lib/node_modules/homebridge-apcaccess/index.js:72:18) at BatteryLevel.emit (node:events:526:28) at /usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/src/lib/Characteristic.ts:1592:14 at new Promise () at BatteryLevel. (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/src/lib/Characteristic.ts:1590:12) at step (/usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:144:27) at Object.next (/usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:125:57) at /usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:118:75 at new Promise () at __awaiter (/usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:114:16) at BatteryLevel.Characteristic.handleGetRequest (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/dist/lib/Characteristic.js:689:38) at BatteryLevel. (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/src/lib/Characteristic.ts:2207:22) at step (/usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:144:27) at Object.next (/usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:125:57) at /usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:118:75 at new Promise () [10/1/2022, 4:10:06 PM] [UPS] Charging state: CHARGING

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[cr3ative]

Published 0.1.2 which will report zero if bad information is passed through. This failure looks transient, so it should just avoid a crash rather than causing bad reporting for a significant period of time.

[grgmll]

Hi, after installing the new version (0.1.2) the battery level value is always at 0%, with the previous version everything was working fine

[cr3ative]

Hm. It should only set to zero if we got NaN to avoid a crash. What's going on?

[grgmll]

with version 0.1.1

[05/10/2022, 11:06:51] [UPS Cantina] Low Battery? BATTERY_LEVEL_NORMAL [05/10/2022, 11:06:51] [UPS Cantina] Battery level NaN problem; recorded as undefined false [05/10/2022, 11:06:51] [homebridge-apcaccess] This plugin threw an error from the characteristic 'Battery Level': Unhandled error thrown inside read handler for characteristic: Assignment to constant variable.. See https://homebridge.io/w/JtMGR for more info. [05/10/2022, 11:06:51] [UPS Cantina] Charging state: CHARGING .... .... .... [05/10/2022, 11:07:35] [UPS Cantina] Low Battery? BATTERY_LEVEL_NORMAL [05/10/2022, 11:07:35] [UPS Cantina] Battery Level: 100 [05/10/2022, 11:07:35] [UPS Cantina] Charging state: NOT_CHARGING

with 0.1.2

0.1.2 [05/10/2022, 11:16:13] [UPS Cantina] Low Battery? BATTERY_LEVEL_NORMAL [05/10/2022, 11:16:13] [UPS Cantina] Battery Level: NaN [05/10/2022, 11:16:13] [homebridge-apcaccess] This plugin generated a warning from the characteristic 'Battery Level': characteristic value expected valid finite number and received "NaN" (number). See https://homebridge.io/w/JtMGR for more info. [05/10/2022, 11:16:13] [UPS Cantina] Charging state: CHARGING .... .... .... [05/10/2022, 11:17:02] [UPS Cantina] Low Battery? BATTERY_LEVEL_NORMAL [05/10/2022, 11:17:02] [UPS Cantina] Battery Level: 0 [05/10/2022, 11:17:02] [UPS Cantina] Charging state: NOT_CHARGING

[upcsymbol]

Hm. It should only set to zero if we got NaN to avoid a crash. What's going on?

The issue is that it's pulling the "100.0 Percent" from apcaccess - which is text. You either need to treat it as such or include the flag to drop value labels. My current fix to getBatteryLevel() below.

getBatteryLevel(callback) {
    // BCHARGE
    let battPctValue = 0;
    let battVal = this.latestJSON.BCHARGE;
    if(battVal != undefined) {
        const battArray = battVal.split(".");
        battPctValue = parseFloat(parseFloat(battArray[0]*-1)*-1);
        this.log('Battery Level: ', battPctValue);
    } else {
        battPctValue = 0;
        this.log('Battery Level: ', battPctValue);
    }
    callback(null, battPctValue);
  }

[cr3ative]

Brilliant, thank you for the incoming value and fix! I’ll get this rolled in soon.

[cr3ative]

Thanks for the logs. It looks like we might just revert as homebridge doesn’t crash even if presented with a bad value. 

[cr3ative]

Published + homebridge-apcaccess@0.1.3 with the fix by @upcsymbol above.

[grgmll]

Thanks, with this update everything seems to work.