getPressure gets stuck with "Conversion in progress" error (Bangle.js 2; fw 2v12.40)

[espruino-discuss2]

Posted at 2022-02-19 by malaire

I've noticed new problem with Bangle.js 2 and Bangle.getPressure():

Once "I2C Error: Arbitration (start)" happens, all future calls to Bangle.getPressure() will fail with "Uncaught Error: Conversion in progress".

This never happened with earlier firmwares but I'm now seeing this quite often with 2v12.40

[espruino-discuss2]

Posted at 2022-02-21 by @gfwilliams

Ok, thanks. I'll take a look. Is this with a KickStarter bangle?

---

Posted at 2022-02-21 by malaire

yes

---

Posted at 2022-02-23 by @gfwilliams

Just fixed in latest firmware I think

---

Posted at 2022-02-25 by malaire

yes, this is fixed in 2v12.58 at least.

btw, did I misunderstand something, but I thought you made the I2C error catchable earlier? Currently in 2v12.58 it can't be catched. (But this is a minor thing, I can work around this.)

---

Posted at 2022-02-28 by @gfwilliams

Currently in 2v12.58 it can't be catched.

It might be handled as a promise rejection - which is different to something that you catch with a try...catch?

---

Posted at 2022-02-28 by malaire

Specifically this code doesn't catch it. Do I need to do something different?

setInterval(() => {
  Bangle.getPressure().then(d => {
    console.log(d.temperature);
  }).catch(()=> {
    // THIS IS NEVER REACHED
    console.log("ERROR");
  });
}, 10 * 1000);

---

Posted at 2022-02-28 by @gfwilliams

Could you try putting a try...catch around that just in case? It shouldn't be needed but would help to track down where the exception comes from

---

Posted at 2022-02-28 by malaire

I've been running with that for over 2 hours now without I2C error, I'll report here if I manage to reproduce that again. (So good news is that it has become quite rare.)

But I did notice that d.temperature from that code sometimes returns completely wrong value. For example here is a list of some successive values:

23.70770094008
23.71263150090
23.72249262342
23.73235374710
-0.01203159983
23.83589561600
23.89013188427
23.92464589151
23.95422933763

---

Posted at 2022-02-28 by malaire

ok, I got I2C error but I don't quite understand this. try...catch catches something but still output says that there is uncaught error.

Output:

23.60415923008
23.60415923008
OUTER: undefined
Uncaught Error: Unhandled promise rejection: Error: I2C Error: Arbitration (start)
23.64360367590
23.64360367590

Code:

setInterval(() => {
  try {
    Bangle.getPressure().then(d => {
      console.log(d.temperature);
    }).catch(error => {
      console.log("INNER: " + error);
    });
  } catch (error) {
    console.log("OUTER: " + error);
  }
}, 10 * 1000);

---

Posted at 2022-03-01 by @gfwilliams

Ok, thanks - that's what I thought then. I guess there is an I2C error not when initialising, but when reading the data from the sensor after a timeout. I could add a check in there for that, and I guess it may help to catch those occasional odd temperature values.

But have you tried using Bangle.on('pressure' and Bangle.setBarometerPower(1)? If you're doing a reading every 10 seconds it's probably better and far more reliable just to keep the barometer on all the time rather than repeatedly powering it on and off

---

Posted at 2022-03-01 by malaire

But have you tried using Bangle.on('pressure' and Bangle.setBarometerPower(1)? If you're doing a reading every 10 seconds it's probably better and far more reliable just to keep the barometer on all the time rather than repeatedly powering it on and off

yes, that works better, but in my clock adjust widget the update interval can be much longer than 10 seconds and Bangle.on('pressure' causes several updates each second so it likely uses a lot more power.

---

Posted at 2022-03-02 by @gfwilliams

Bangle.on('pressure' causes several updates each second so it likely uses a lot more power.

This is true, but it may not be as bad as you think especially in the ~10 second case - since the barometer takes 1 second to get started each time anyway.

---

Posted at 2022-03-02 by malaire

Is there any (simple) way to measure power consumption?

Somehow disconnecting internal battery and using only USB power would be ideal, but I don't think that is possible?

---

Posted at 2022-03-02 by @gfwilliams

Well, I have a Bangle here where I took it to bits, disconnected the battery and then power it from an external battery with a power meter, but that's about the only method I know of, and it's not easy at all :(

[banglejsdev]

It doesn't seem to be a big problem but I'm getting the same error with 2v26 (Kickstarter version):

2v26 (c) 2025 G.Williams
Uncaught Error: Conversion in progress
at line 9 col 109 in .boot0
...ressure?Bangle.getPressure():Promise.resolve({})).then(c=>{O...
^
in function called from system

My Bangle 2 was connected to the IDE and had the LCARS watchface showing when this error started appearing periodically in the console.

[gfwilliams]

I could be wrong but I think what's happening is that the health app is now trying to store the altitude every 10 minutes, and I guess LCARS is querying the barometer too? (Not sure).

It's not a hardware error, its just the software errors if you ask for pressure when pressure is already being requested.

Looking at the code again there's really no reason why that should be the case - it could just return the same promise that the currently in-progress getPressure call was going to return. I've now fixed that so if you install the cutting edge release (or 2v27 when released) it'll be fine

[banglejsdev]

I believe your brilliant inference is correct, as I do indeed have the Health app installed as well, thanks! As it's not causing me any problems I'll wait until 2v27 is officially released to confirm the same error doesn't occur anymore.