My Pokit scope(s)

New 02Aug2023. Updated 24Nov2023. This note is about some individual scope channel devices which send their curves to a mobile app. This app runs on several platforms. “My Pokit scopes” as in plural, is this correct? Or should it be called “My Pokit scope”? So I changed it to “My Pokit scope(s)”. Observe Standard disclaimer.

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Intro

  • I write this because I need to stay somewhat updated. I do read some student reports over the year (here), but I can’t start with any of those. But here is a physical and published product, a nice vehicle to start off from. Even more, maybe you think it interesting
  • My other oscilloscope blog notes (search for “scope” here): Technology
  • For me this all started one time. Many, many years ago: Radiobyggboken (Google translate) – and then some years ago: A scope to fulfill

Pokit Innovations

Pokit Innovations is a small Sydney (Australia) based startup with some interesting products. Start at www.pokitinnovations.com. Their parent company is Ingenuity Design Group. It’s pronounced like “pocket” → “pockit”, not “poke-it” (which was my first try, as some Americans would say, a guy at Pokit told me in a mail. But then, I did spend a year in the US.. (’67-’68 at Fisher High School (again many, many years ago)).

Pokit made a custom order for me, since their shopping software did not differentiate between discount (valid for one one per order) and bundles (several per order). Since I wanted two bundles (both were discounted) adding one bundle removed the discount of the other.

Then they asked me, and I was happy to reply: “What do you plan to use your Pokit devices for?”

  • Right now, experimenting with my Beep-BRRR project (listening device for hearing deficit people): My Beep-BRRR notes (some log & movies). I need to do this off home, so I have been looking for a portable scope for a long time. Plus, will also log from it so see how close to limits I am, and when. My plan is to use Pokit Meter for long-time logging and Pokit Pro for observing the spectra. One of the two Pros will be used as a trigger for the spectra picked up by the other
  • Blogging about my experience with it (for fun, no income or gifts from it): (here). Again: Standard disclaimer

“What is your occupation and what industry do you work in?”

  • I retired as a senior development engineer, having developed safety-critical HW and SW for 40+ years..

There is an interview with the design engineer behind the Pokit instruments at [6]. Being inspired by my father and grandfather myself, I understand what he’s saying there.

Some collected facts and comments

Collected from mails with a senior guy at the company. I have been allowed to publish this.

  • The SoC (System on a chip) in the units is the Silicon Labs EFR32BG12 [2]. It contains a BLE (Bluetooth Low Energy) radio. It seems to contain everything except a (proper?) task concept and a scheduler in the firmware (*)
  • If you have a second Pokit Pro you can use it as an external trigger for the first one and they will synchronize their waveforms down to about 1-2 microseconds. You can do this for up to 4 channels (one trigger channel, 3 slaves). This allows you to compare signals that correlate in time or measure a signal against a clock pulse (which sounds like what you want).
  • The units may be updated over the air from the app. They use Silicon Labs OTA (over-the-air) protocol [1]. They say “which we do often to fix bugs, improve features, etc.
  • The user manual and low resolution pictures of how the Pokit Pro looks inside (and outside for that matter) are published in the FCC bundle at [5]
  • Any mails from “marsello” are valid. They seem to update earned points

(*) Pokit would (of course?) not disclose whether the units run any kind of operating system or if they use interrupts as their basic task model. But (thinking aloud), between those concepts is the Silicon Labs’ system described as “12-channel Peripheral Reflex SystemPRS [3] which is part of the EMLIB low-level peripheral library (not for radio functions) [4]. Thus “EMLIB modules are provided for all peripherals and core features. The library implements no interrupt handlers. Static data, critical sections and module interdependencies are kept at a minimum.” I must admit that this looks rather nice, and as I write (and look up these things) I do learn. I get a feeling that a built-in low-level task concept comes out of this SW library. I then think of “low-level” as something where “safe” tasks (which start at task-level encapsulation) don’t come out of the box. Still, so much better than just interrupt handlers, where I guess that removing some of them only is for the good. I was used to chan with occam on transputers and am daily using chan with xC on XMOS xCore machines, where both architectures handle most of this in silicon or microcode (lots of blogs about this here). Tasks then just are present. Silicon Labs seems to have used the same channel word (which also rings a bell for go (golang) programmers, where chan is a SW matter only). This is interesting. I need to read more about it. All this being said, I have no idea whether this library is used in the Pokit instruments, even if I do guess this is hard to avoid..

(aside)n begin {
    The PRS is mentioned, along with Nordic Semi's (patented!) PPI in the Wikipedia article
    Autonomous peripheral operation (below). But PPI and DPPI are, as far as I learn,
    functionality implemented in hardware, with real-time guarantees
} end

Log

My devices

Fig.1 – Goodies box

07Sep2023 (updated 24Nov2023)

Pokit app (Version 1.7.0 as seen on the Devices screen, bottom right).

  1. CH 1: Pokit Meter. (Black). FW: 1.6.0. (HW V1.70) (Since the cable winding got stuck I returned it in cooperation with Pokit support; a replacement is on its way)
  2. CH 2: Pokit Pro serial number 26007 (Slate Gray with Red). FW: V1.8.0 after update. (HW: V1.0)
  3. CH 3: Pokit Meter. (Transparent white). FW: 1.6.0. (HW V1.70)
  4. CH 4: Pokit Pro serial number 100008360 (Classic Gray with Orange). FW: V1.8.0 after update. (HW: V1.0)

Log 01

Newest at the bottom:

Log 01.01

Devices show up and are paired quite nicely. LOCATE starts a beep and a blinking on the Pros.

Log 01.02

Nothing happens if I try to LOCATE the two Meters, only the busy icon shows up for a short time. Nothing about this in the sparse manual (p_help) that came with it. So it’s rather hard to find out which is which. Observe that there is no button for Meter on, off or wake-up. Read about this at p_help. (However the Pro needs a press on its button to connect. The app would say “Connectiong. Press Bottom To Wake” for the Pro, but only “Connecting” for the Meter. (I was taught in school that prepositions(?)  should not have capital first letter in headings. I mean “To Wake” vs. “to Wake”))

Log 01.03

One of the Pros had its connection strength graphics grayed put but the LOCATE still worked. When is the connection checked and the indicator updated?

Log 01.04

Setting the TYPE on the Pro has these colour alternatives: gray, red, yellow and orange. But they seem to exist as colour combinations when you order:  Classic Gray with Orange, Slate Gray with Red, Classic Gray with Slate and Slate Gray with Yellow. Legend seems to be “body colour with end colour”. The proof is that orange only exists as the end. I recognise the three, but not the gray. It’s probably slate. I think that the app should have the same colour combinations as the ordering system has. Is a plant green or red if its flower is red? It’s red. But it’s not as obvious with advanced scope probes.

By the way, “light gray” is called “classic gray” and “dark gray” is called “slate gray“. There certainly are some shades of gray (Wikipedia) for me.

Log 01.05

Setting the color on the Meters is inactive in the app. No: I have to press the pencil, not the field. Strange. This goes for more settings. Smells of one source code, several platforms..

Log 01.06

I updated both Pros to FW: V1.8.0. (HW: V1.0).

  1. The app said: “Updating, do NOT remove pokit device battery or leave this application”. The Pro does not have a removable battery
  2. What does it mean to not “leave” the application?
  3. What happens if the iPhone’s screen had its light decreased during this? Mine did, it was ok
  4. I hope it won’t enter idle, that the app ensures that this does not happen?
  5. And again, if this happens, will the update boot loader have kept a copy of the original firmware and install it later on, or is the boot loader able to update on top of a “half update”?

Log 01.07

The Meters and the Pros each take up a channel. For me I’m full with CH 1 – CH 4. It looks like these are created equal. Since only the Pro may be used as a trigger input from another Pro, the Meter and the Pro have different behaviour. I have yet to discover how this is reflected in the app.

Log 01.08

I see that on a Meter LOCATE is shown as grayed out. It then also says “Connecting”. After some time LOCATE is ok and its “Connected”. Does this happen at random? I can also see LOCATE grayed out but still “Connected” and 3 signal strength bars. (All for my black meter)

Log 01.09

Signal strength indicators vary quite some between the devices, even if they all four lay on the table around the iPhone. Right now I have 3, 3,1,3. This is probably normal.

Communities / Help

The Pokit communiny is at p_help. I have referenced some p_help above as well.

One can also raise tickets with Pokit support.

References

Wiki-refs: Autonomous peripheral operation, Bluetooth Low Energy (BLE), Over-the-air update (OTA), System on a chip

  1. Uploading Firmware Images Using OTA DFU, see here
  2. EFR32BG12 Gecko Bluetooth ®Low Energy SoC Family Data Sheet, see here
  3. EFR32 Blue Gecko 12 Software Documentation: PRS, see here
  4. –”–: EMLIB, see here
  5. 2ARUE-POKPRO FCC ID Equipment: Pokit Innovations PTY. LTD. -POKPRO see here
  6. Inspiring Dads: Interview with the Pokit Electrical Engineer, “My name is Stephen Geary, and I’m an electrical engineer for Pokit Innovations“, see here

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